Researchers Database

koike soichi

    CenterforCommunityMedicineDivisionofHealthPolicyandManagement Professor
Last Updated :2021/12/04

Researcher Information

URL

J-Global ID

Research Areas

  • Life sciences / Healthcare management, medical sociology
  • Life sciences / Hygiene and public health (non-laboratory)

Published Papers

  • Education Policies to Increase Rural Physicians in Japan: A Nationwide Cohort Study Research
    Matsumoto M, Matsuyama Y, Kashima S, Koike S, Okazaki Y, Kotani K, Owaki T, Ishikawa S, Iguchi S, Okazaki H, Maeda T
    Human Resources for Health 19 102  2021/08 [Refereed][Not invited]
  • Effect and Significance of incorporating access in estimating the number of required physicians: Focus on differences in population density in the target area
    Tatsuya Suzuki, Soichi Koike, Masatoshi Matsumoto
    International Journal of Health Geographics (in press) 20 (1) 21  2021/05 [Refereed][Not invited]
  • 新 秀直, 廣瀬 稔, 井出 博生, 小池 創一
    医療機器学 (一社)日本医療機器学会 90 (3) 245 - 255 1882-4978 2020/06
  • Shuhei Yoshida, Masatoshi Matsumoto, Saori Kashima, Soichi Koike, Susumu Tazuma, Takahiro Maeda
    BMC family practice 20 (1) 147 - 147 1471-2296 2019/10 [Refereed][Not invited]
     
    BACKGROUND: Geographical maldistribution of physicians, and their subsequent shortage in rural areas, has been a serious problem in Japan and in other countries. Family Medicine, a new board-certified specialty started 10 years ago in Japan by Japan Primary Care Association (JPCA), may be a solution to this problem. METHODS: We obtained the workplace information of 527 (78.4%) of the 672 JPCA-certified family physicians from an online database. From the national census data, we also obtained the workplace information of board-certified general internists, surgeons, obstetricians/gynaecologists and paediatricians and of all physicians as the same-generation comparison group (ages 30 to 49). Chi-squared test and residual analysis were conducted to compare the distribution between family physicians and other specialists. RESULTS: Five hundred nineteen JPCA-certified family physicians and 137,587 same-generation physicians were analysed. The distribution of family physicians was skewed to municipalities with a lower population density, which shows a sharp contrast to the urban-biased distribution of other specialists. The proportion of family physicians in non-metropolitan municipalities was significantly higher than that expected based on the distribution of all same-generation physicians (p < 0.001). CONCLUSIONS: Family physicians distributed in favour of rural areas much more than any other specialists in Japan. The better balance of family physician distribution reported from countries with a strong primary care orientation seems to hold even in a country where primary care orientation is weak, physician distribution is not regulated, and patients have free access to healthcare. Family physicians comprise only 0.2% of all Japanese physicians. However, if their population grows, they can potentially rectify the imbalance of physician distribution. Government support is mandatory to promote family medicine in Japan.
  • Matsui H, Koike S, Fushimi K, Wada T, Yasunaga H
    Annals of Clinical Epidemiology 1 (3) 86 - 94 2019/10 [Refereed][Not invited]
  • Kawaguchi H, Koike S, Ohe K
    JMIR Medical Informatics 7 (2) e14026  2019/06 [Refereed][Not invited]
  • Koike S, Isse T, Kawaguchi H, Ogawa M
    Occupational Medicine 69 (2) 139 - 142 0962-7480 2019/03 [Refereed][Not invited]
  • Koike S, Matsumoto M, Kawaguchi H, Ide H, Atarashi H, Kotani K, Yasunaga H
    BMC Health Services Research 18 615  1472-6963 2018/08 [Refereed][Not invited]
  • Hideaki Kawaguchi, Soichi Koike, Kazuhiko Ohe
    International Journal of Medical Informatics 115 114 - 119 1872-8243 2018/07 [Refereed][Not invited]
     
    Purpose: Regional differences in the adoption of electronic medical records (EMR) are a major problem, yet little is known about these differences internationally. We analyzed regional differences in EMR adoption in Japan and evaluated factors associated with these differences. Methods: This nationwide ecological study used secondary data from all secondary medical service areas (SMSAs) in fiscal years 2008 (n = 348) and 2014 (n = 344). For each SMSA we collected the following information from a Japanese national database: the number of medical facilities that had adopted EMR, the population density, the average per capita income, the number of working doctors per 1000 people, and the proportion of interns to all working doctors. To adjust for medical facility characteristics in each SMSA, such as number of beds, public versus private hospital, and hospital type (psychiatric or other), we estimated the standardized adoption ratio (SAR) for EMR adoption, modeled on the standardized mortality ratio. We calculated Moran's I for the SAR and investigated whether the SAR had spatial autocorrelations. We evaluated the association between the SAR and regional factors with a conditional autoregressive model. We compared these results in 2008 and 2014, for both hospitals and clinics. Results: While the EMR adoption rate in SMSAs increased, Moran's I of the SAR in hospitals was close to 1 in both 2008 and 2014, and Moran's I of the SAR in clinics increased from 2008 to 2014. For hospitals, there was a significant association between the proportion of interns to all working doctors and the SAR only in 2008. For clinics, average income in the SMSA was positively associated with the SAR, whereas the number of working doctors was negatively associated with the SAR in both 2008 and 2014. Population density was positively associated with the SAR only in 2014. Conclusion: From 2008 to 2014, EMR adoption in Japan generally increased, but geographical differences did not improve. Regional factors associated with the SAR were different for hospitals than for clinics. Therefore, the government should take different approaches for clinics and hospitals to improve regional differences in EMR adoption, especially in providing financial and technical support.
  • Hiroo Ide, Shunsuke Doi, Hidenao Atarashi, Shinsuke Fujita, Soichi Koike
    Human Resources for Health 16 (1) 26  1478-4491 2018/06 [Refereed][Not invited]
     
    Background: The uneven geographical distribution of physicians in Japan is a result of those physicians electing to work in certain locations. In order to understand this phenomenon, it is necessary to analyze the geographic movement of physicians across the Japanese landscape. Methods: We obtained individual data on physicians from 1978 to 2012 detailing their attributes, work institutions, and locations. The data are from Japanese governmental sources (the Survey of Physicians, Dentists, and Pharmacists). The total sample size was 122150 physicians, with 77.5% being male and 22.5% female. After obtaining the data, we calculated the geographical distance of each physician's movement by using geographic information systems software (GIS ArcGIS, ESRI, Inc., CA, USA). Geographical distance was then converted into time distance. We compared the resulting median values through nonparametric testing and then conducted a multivariate analysis. Our next step involved the use of an age-period-cohort (APC) model to measure the degree of impact three points of data, experience (experience years), the historical and environmental context of the data (survey year), and physician cohort (registration year) had on the movement of each physician. Results: The ratio of female physicians who selected an urban area as their first working location was higher than that of male physicians. However, the selection of an urban area was becoming more popular as a first working location for both males and females as the year of data increased. The overall distance of geographical movement for female physicians was less than it was for male physicians. Physicians moved the greatest distance between their second and fourth years following license acquisition, at which point the time distance became shorter. The median time distance was 46min in 2000 and 22min in 2008. The physicians in our study did not move far from their first working location, and the overall distance of movement lessened in the more recent years of study. The median distance of movement after 20years was 25.9km for male physicians, and 19.1km for female physicians. The results of the APC model indicated that the effects of experience years (age) gradually declined, that the survey year (period) effects increased, and that the registration year (cohort) effects increased initially before leveling off. Conclusions: The trends following the introduction of the new mandatory training system in 2004 may imply that the concentration of physicians in Japan's urban areas is expected to increase. After 2000, the effect of that period on physicians explains their geographical movements more so than the factor of their age.
  • Masatoshi Matsumoto, Kazuki Kimura, Kazuo Inoue, Saori Kashima, Soichi Koike, Susumu Tazuma
    PLoS ONE 13 (6) e0198317  1932-6203 2018/06 [Refereed][Not invited]
     
    Background The disparity in the number of urban and rural physicians is a social problem in Japan. There may also be a disparity in the age of physicians. This study longitudinally examines both geographic and age distributions of physicians. Methods Individual data from the Survey of Physicians, Dentists and Pharmacists in 1994, 2004 and 2014 and municipality data from the National Population Census were used. The 2015 municipality border was applied to all years, and all municipalities were classified into equal-size quintiles based on population density. Both municipalities and physicians were longitudinally observed. Results Between 1994 and 2014, the number of physicians per 100,000 population increased by 31.8% in the most urban group of municipalities and 17.4% in the most rural group. The average age of physicians was highest in the most rural and lowest in the most urban group. The difference in average age between the urban and rural physicians widened from 2.1 years in 1994 to 6.0 years in 2014. This disparity is particularly pronounced among hospital physicians (from 1.5 years in 1994 to 7.6 years in 2014). In the most rural group, the number of hospital physicians younger than 40 years old has decreased by 59.4%, while the number of those 55–70 has grown by 153% and the number older than 70 years old by 41.0%. Between 1994 and 2004, only 23.0% of hospital physicians younger than 40 years old were retained in the most rural group the retention rate fell to 19.3% between 2004 and 2014, while the rates increased in older physicians. Conclusions The uneven distribution of physicians is increasing in Japan, as is the aging of rural hospital physicians. Shortage of physicians in rural areas may be more serious than that shown as their headcount.
  • Hideaki Kawaguchi, Soichi Koike, Ryota Sakurai, Kazuhiko Ohe
    International Journal of Health Geographics 17 (1) 3  1476-072X 2018/05 [Refereed][Not invited]
     
    Background: Coronary computed tomography angiography (CTA) has demonstrated high diagnostic accuracy for detection of coronary artery stenosis, and healthcare providers can detect coronary artery disease in earlier stages before it develops into more serious clinical conditions such as acute myocardial infarction (AMI). We hypothesized that the mortality ratio of AMI in regions with a higher density of coronary CTA is lower than that in regions with a lower density of coronary CTA. Methods: This ecological and cross-sectional study using secondary data targeted all secondary medical service areas (SMSAs) in Japan (n=349). We obtained the numbers of cardiologists, institutions with coronary CTA, and institutions with a cardiac catheterization laboratory (CCL) as medical resources, socioeconomic factors, lifestyle factors, exercise habit factors, and AMI mortality data from a Japanese national database. We evaluated the association between the number of these medical resources and the standardized mortality ratio (SMR) of AMI in each SMSA using a hierarchical Bayesian model accounting for spatial autocorrelation (i.e., a conditional autoregressive model). We assumed a Poisson distribution for the observed number of AMI-related deaths and set the expected number of AMI-related deaths as the offset variable. Results: The number of institutions with coronary CTA was negatively and significantly associated with the SMR of AMI (relative risk [RR] 0.900 95% credible interval [CI] 0.848-0.953), while the SMR in each SMSA was not significantly associated with the number of either cardiologists (RR 0.997 95% CI 0.988-1.004) or institutions with a CCL (RR 1.026 95% CI 0.963-1.096). Conclusions: We observed a significant association between the number of institutions with coronary CTA and the SMR of AMI. Effective allocation of coronary CTA in each region is recommended, and it would be important to clarify the standing position of coronary CTA in regional networking for AMI treatment in the future.
  • 新 秀直, 廣瀬 稔, 井出 博生, 小池 創一
    医療機器学 (一社)日本医療機器学会 88 (2) 163 - 163 1882-4978 2018/04
  • 中村 好一, 松原 優里, 笹原 鉄平, 古城 隆雄, 阿江 竜介, 青山 泰子, 牧野 伸子, 小池 創一, 石川 鎮清
    日本公衆衛生雑誌 日本公衆衛生学会 65 (2) 72 - 82 0546-1766 2018/02 
    目的 地方紙における遺族の自己申告型死亡記事の記載事項を集計し、その地域での死亡やそれに伴う儀式の実態を明らかにするとともに、死亡記事のデータベースとしての利点と問題点を明らかにする。方法 栃木の地方紙である下野新聞の自己申告型死亡記事「おくやみ」欄に掲載された2011〜2015年の栃木県内の死亡者全員のデータを集計解析し、一部の結果は人口動態統計と比較した。観察項目は掲載年月日、市町村、住所の表示(市町村名のみ、町名・字まで、番地まで含めた詳細な住所)、氏名、性別、死亡年月日、死因、死亡時年齢、通夜・告別式などの名称、通夜などの年月日、告別式などの年月日、喪主と喪主の死亡者との続柄の情報である。結果 観察期間中の掲載死亡者数は69,793人で、同時期の人口動態統計による死亡者数の67.6%であった。人口動態統計と比較した掲載割合は男女で差がなく、小児期には掲載割合が低く、10歳代で高く、20歳代で低下し、以降は年齢とともに上昇していた。市町別の掲載割合は宇都宮市や小山市など都市化が進んだ地域では低く、県東部や北部で高い市町がみられた。最も掲載割合が高かったのは茂木町(88.0%)、低かったのは野木町(38.0%)であった。死亡日から通夜や告別式などの日数から、東京などで起こっている火葬場の供給不足に起因する火葬待ち現象は起こっていないことが判明した。六曜の友引の日の告別式はほとんどなく、今後、高齢者の増加に伴う死者の増加によって火葬場の供給不足が起こった場合には、告別式と火葬を切り離して友引に火葬を行うことも解決策の1つと考えられた。死亡者の子供、死亡者の両親、死亡者の子供の配偶者が喪主の場合には、喪主は男の方が多いことが判明した。老衰、自殺、他殺の解析から、掲載された死因の妥当性は低いことが示された。結論 栃木県の地方紙である下野新聞の自己申告型死亡記事「おくやみ」欄の5年分の観察を行い、実態を明らかにした。約3分の2に死亡が掲載されており、データベースとしての使用に一定の価値があると考えられたが、記載された死因の妥当性は低いことが判明した。(著者抄録)
  • Nakamura Y, Matsubara Y, Sasahara T, Kojo T, Ae R, Aoyama Y, Makino N, Koike S, Ishikawa S
    Japanese Journal of Public Health 65 (2) 72 - 82 2187-8986 2018/02 [Refereed][Not invited]
     
    Objectives To reveal the features of death and subsequent funeral services, we analyzed self-reported obituaries in The Shimotsuke, a local daily newspaper in Tochigi, Japan. In addition, the usefulness and disadvantages of such a database of deaths based on the obituaries were discussed.Method For a 5-year period, from January 2011 through December 2015, all the obituary columns in The Shimotsuke were computerized as a database and analyzed. Some results were compared with the vital statistics data in the corresponding period of time. Data analyzed were: dead persons' address (municipalities), name, sex, cause of death, age at death, date of death and funeral services, the chief mourner (Moshu), and so on.Results During the observed 5-year period, 69,793 deaths appeared in the columns, which were 67.6% of the all deaths in the vital statistics. No difference was observed in the proportions between the sexes in the published deaths in comparison with the vital statistics. In both sexes, the proportion was low in 0-9 years old, then high among 10-19 years, decreasing in 20s, and after then the proportion increased according to the age. The proportion was low in city areas, such as Utsunomiya and Oyama, and high in some cities and towns in the northern or eastern parts of Tochigi prefecture. The highest was in Motegi Town (88.0%), and the lowest was Nogi Town (38.0%), which is located in the southern-most part of the prefecture and is closest to the Tokyo metropolitan area. Almost all the funeral services were conducted within a week of the death, and no delays were observed to have been caused by the short supply of cremation services, which exists in large cities in Japan. In case where the chief mourner was a child, a parent, or a spouse of a child, the male sex was dominant. Analyses of death from senile decay, suicide, and homicide indicated that the accuracy of the published cause of death was low. The date of the funeral services was strongly influenced by superstitions in this country.Conclusions Observations of the self-reported obituaries in a local daily newspaper over five years revealed the situations of the deaths in the area that could not be observed using vital statistics. Despite limitations, the information was partially useful as a database.
  • Soichi Koike, Masatoshi Matsumoto, Hiroo Ide, Hideaki Kawaguchi, Masahisa Shimpo, Hideo Yasunaga
    BMC MEDICAL EDUCATION 17 83  1472-6920 2017/05 [Refereed][Not invited]
     
    Background: Establishing and managing a board certification system is a common concern for many countries. In Japan, the board certification system is under revision. The purpose of this study was to describe present status of internal medicine specialist board certification, to identify factors associated with maintenance of board certification and to investigate changes in area of practice when physicians move from hospital to clinic practice. Methods: We analyzed 2010 and 2012 data from the Survey of Physicians, Dentists and Pharmacists. We conducted logistic regression analysis to identify factors associated with the maintenance of board certification between 2010 and 2012. We also analyzed data on career transition from hospitals to clinics for hospital physicians with board certification. Results: It was common for physicians seeking board certification to do so in their early career. The odds of maintaining board certification were lower in women and those working in locations other than academic hospitals, and higher in physicians with subspecialty practice areas. Among hospital physicians with board certification who moved to clinics between 2010 and 2012, 95.8% remained in internal medicine or its subspecialty areas and 87.7% maintained board certification but changed their practice from a subspecialty area to more general internal medicine. Conclusion: Revisions of the internal medicine board certification system must consider different physician career pathways including mid-career moves while maintaining certification quality. This will help to secure an adequate number and distribution of specialists. To meet the increasing demand for generalist physicians, it is important to design programs to train specialists in general practice.
  • Hidenao Atarashi, Hiroo Ide, Soichi Koike
    Journal of Clinical Engineering 41 (3) 127 - 133 1550-3275 2016/06 [Refereed][Not invited]
     
    To ensure the safety of medical equipment, appointing medical equipment safety managers (MESMs) in medical institutions was made compulsory in Japan in 2007. This study aimed to describe the current status of clinical engineers (CEs) and analyze changes in the specialties of those selected as MESMs in Japan. We analyzed 2008 and 2011 government census data on hospitals. The proportion of hospitals where CEs were MESMs increased significantly, from 16.6% in 2008 to 18.5% in 2011. Although CEs are optimal as MESMs in terms of expertise, only one-third of hospitals (2,743/8,157) employed CEs.
  • Miho Ishimaru, Sachiko Ono, Hideo Yasunaga, Hiroki Matsui, Soichi Koike
    Journal of public health dentistry 76 (3) 241 - 8 2016/06 [Refereed][Not invited]
     
    OBJECTIVES: Appropriate health policies for the supply of dentists have been an ongoing issue in many developed countries. The purpose of this study was to estimate the future distribution of dentists with different working statuses in Japan and to discuss policy implications about the supply of dentists in any country. METHODS: This was a retrospective cohort study using data from the National Survey of Physicians, Dentists and Pharmacists for 1972-2012. Based on data from the 2010 and 2012 surveys, we calculated by means of a Markov model the future number of dentists with different working statuses until 2042 according to sex. RESULTS: We estimated that the total number of active dentists will decrease from 2012 to 2042. The number of active dentists per 1,000 population was predicted to reach a peak in 2018, decrease by 4.2% from 2012 to 2038, and thereafter slightly increase. With regard to working status, the number of dentists with their own practices per 1,000 people was predicted to have reached a peak in 2014 and decrease by 22.0% until 2042. We estimated that the number of dentists used in dental clinics per 1,000 population will increase continuously between 2012 and 2042 by 20.0%. CONCLUSIONS: Our study suggests that maintaining this supply of dentists may lead to maldistribution of their working status in the future.
  • Soichi Koike, Atsushi Shimizu, Masatoshi Matsumoto, Hiroo Ide, Hidenao Atarashi, Hideo Yasunaga
    SURGERY TODAY 46 (6) 661 - 667 0941-1291 2016/06 [Refereed][Not invited]
     
    To investigate the career pathways of board-certified surgeons' and the factors associated with them maintaining their certification in Japan. We analyzed data from the surveys of physicians, dentists and pharmacists. A multivariate logistic regression model was used to investigate whether factors such as gender, year of registration, place of work, and subspecialty board certification were associated with maintaining board certification. Most Japanese surgeons attain board certification within 5-10 years of initial medical registration. After adjusting for possible confounding factors, the odds of maintaining board certification were significantly lower for women, those who were beyond 20 years post-registration, those who worked in hospitals other than academic hospitals or clinics, and those who had board certification in surgery only. Of the total board-certified surgeons analyzed, 93.2 % continued to work in hospitals and 2.8 % moved to clinics within 2 years. Of those who moved from hospitals to clinics, half continued to practice surgery, while nearly 40 % changed their specialty to internal medicine. It is necessary to establish a special training system for mature surgeons who move from surgery to general practice later in their careers. As the number of female surgeon increases, a support system is also required to secure the future supply of surgeons.
  • Hideaki Kawaguchi, Soichi Koike
    PLOS ONE 11 (2) 1932-6203 2016/02 [Refereed][Not invited]
     
    Background Regional disparity in suicide rates is a serious problem worldwide. One possible cause is unequal distribution of the health workforce, especially psychiatrists. Research about the association between regional physician numbers and suicide rates is therefore important but studies are rare. The objective of this study was to evaluate the association between physician numbers and suicide rates in Japan, by municipality. Methods The study included all the municipalities in Japan (n = 1,896). We estimated smoothed standardized mortality ratios of suicide rates for each municipality and evaluated the association between health workforce and suicide rates using a hierarchical Bayesian model accounting for spatially correlated random effects, a conditional autoregressive model. We assumed a Poisson distribution for the observed number of suicides and set the expected number of suicides as the offset variable. The explanatory variables were numbers of physicians, a binary variable for the presence of psychiatrists, and social covariates. Results After adjustment for socioeconomic factors, suicide rates in municipalities that had at least one psychiatrist were lower than those in the other municipalities. There was, however, a positive and statistically significant association between the number of physicians and suicide rates. Conclusions Suicide rates in municipalities that had at least one psychiatrist were lower than those in other municipalities, but the number of physicians was positively and significantly related with suicide rates. To improve the regional disparity in suicide rates, the government should encourage psychiatrists to participate in community-based suicide prevention programs and to settle in municipalities that currently have no psychiatrists. The government and other stakeholders should also construct better networks between psychiatrists and non-psychiatrists to support sharing of information for suicide prevention.
  • Soichi Koike, Masatoshi Matsumoto, Hiroo Ide, Saori Kashima, Hidenao Atarashi, Hideo Yasunaga
    INTERNATIONAL JOURNAL OF HEALTH GEOGRAPHICS 15 4  1476-072X 2016/01 [Refereed][Not invited]
     
    Background: In Japan, the number of obstetrics facilities has steadily decreased and the selection and concentration of obstetrics facilities is progressing rapidly. Obstetrics services should be concentrated in fewer hospitals to improve quality of care and reduce the workload of obstetricians. However, the impact of this intensification of services on access to obstetrics hospitals is not known. We undertook a simulation to examine how the intensification of obstetrics services would affect access to hospitals based on a variety of scenarios, and the implications for health policy. Methods: The female population aged between 15 and 49 living within a 30-min drive of an obstetrics hospital was calculated using a Geographic Information System for three possible intensification scenarios: Scenario 1 retained facilities with a higher volume of deliveries without considering the geographic boundaries of Medical Service Areas (MSAs, zones of healthcare administration and management); Scenario 2 prioritized retaining at least one hospital in each MSA and then retained higher delivery volume institutions, while Scenario 3 retained facilities to maximize population coverage using location-allocation modeling. We also assessed the impact of concentrating services in academic hospitals and specialist perinatal medical centers (PMCs) alone. Results: In 2011, 95.0 % of women aged 15-49 years lived within a 30-min drive of one of 1075 obstetrics hospitals. This would fall to 82.7 % if obstetrics services were intensified into academic hospitals and general and regional PMCs. If 55.0 % of institutions provided obstetrics services, the coverage would be 87.6 % in Scenario 1, whereas intensification based on access would achieve over 90.5 % coverage in Scenario 2 and 93.9 % in Scenario 3. Conclusions: Intensification of obstetrics facilities impairs access, but a greater caseload and better staffing have the potential advantages of better clinical outcomes and reduced costs. It is essential to consult residents of hospital catchment areas when reorganizing clinical services; a simulation is a useful means of informing these important discussions.
  • Masatoshi Matsumoto, Soichi Koike, Saori Kashima, Kazuo Awai
    PLOS ONE 10 (9) 1932-6203 2015/09 [Refereed][Not invited]
     
    Background Japan has the most CT and MRI scanners per unit population in the world, and as these technologies spread, their geographic distribution is becoming equalized. In contrast, the number of radiologists per unit population in Japan is the lowest among OECD countries and their geographic distribution is unknown. Likewise, little is known about the use of teleradiology, which can compensate for the uneven distribution of radiologists. Methods Based on the Survey of Physicians, Dentists and Pharmacists and the Static Survey of Medical Institutions by the Ministry of Health, Labour and Welfare, a dataset of radiologists and CT and MRI utilizations in each of Japan's 1811 municipalities was created. The inter-municipality equity of the number of radiologists was evaluated using Gini coefficient. Logistic regression analysis, based on Static Survey data, was performed to evaluate the association between hospital location and teleradiology use. Results Between 2006 and 2012 the number of radiologists increased by 21.7%, but the Gini coefficient remained unchanged. The number of radiologists per 1,000 CT (MRI) utilizations decreased by 17.9% (1.0%); the number was highest in metropolis and lowest in town/village and the disparity has widened from 1.9 to 2.2 (1.6 to 2.0) times. The number of hospitals and clinics using teleradiology has increased (by 69.6% and 18.1%, respectively). Hospitals located in towns/villages (odds ratio 1.61; 95% confidence interval 1.26-2.07) were more likely to use teleradiology than those in metropolises. Conclusions Contrary to the CT and MRI distributions, radiologist distribution has not been evened out by the increase in their number; in other words, the distribution of radiologists was not affected by market-derived spatial competition force. As a consequence, the gap of the radiologist shortage between urban and rural areas is increasing. Teleradiology, which is one way to ameliorate this gap, should be encouraged.
  • Masatoshi Matsumoto, Soichi Koike, Shigeki Matsubara, Saori Kashima, Hiroo Ide, Hideo Yasunaga
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 41 (6) 919 - 925 1341-8076 2015/06 [Refereed][Not invited]
     
    AimA shortage of obstetricians with increased workload is a social problem in Japan. In response, the government and professional bodies have accelerated the selection and concentration' of obstetric facilities. The aim of this study was to evaluate the recent trend of selection and concentration. MethodsWe used data on the number of deliveries and of obstetricians in each hospital and clinic in Japan, according to the Static Survey of Medical Institutions in 2005, 2008 and 2011. To evaluate the inter-facility equality of distribution of the number of deliveries, number of obstetricians and number of deliveries per obstetrician, Gini coefficients were calculated. ResultsThe number of obstetric hospitals decreased by 20% and the number of deliveries per hospital increased by 26% between 2005 and 2011. Hospital obstetricians increased by 16% and the average number of obstetricians per hospital increased by 19% between 2008 and 2011. Gini coefficient of deliveries has significantly decreased. In contrast, Gini coefficient of deliveries per obstetrician has significantly increased. The degree of increase in obstetricians and of decrease in deliveries per obstetrician was largest at the hospitals with the highest proportion of cesarean sections. The proportion of obstetric hospitals with the optimal volume of deliveries and obstetricians, as defined by Japan Society of Obstetrics and Gynecology, was 4% in 2008, and it had doubled to 8.1% 3 years later. ConclusionThe selection and concentration of obstetric facilities is progressing rapidly and effectively in Japan.
  • Masatoshi Matsumoto, Soichi Koike, Saori Kashima, Kazuo Awai
    PLOS ONE 10 (5) 1932-6203 2015/05 [Refereed][Not invited]
     
    Background Japan has the most CT and MRI scanners per unit population in the world; however, the geographic distribution of these technologies is currently unknown. Moreover, nothing is known of the cause-effect relationship between the number of diagnostic imaging devices and their geographic distribution. Methods Data on the number of CT, MRI and PET devices and that of their utilizations in all 1829 municipalities of Japan was generated, based on the Static Survey of Medical Institutions conducted by the government. The inter-municipality equity of the number of devices or utilizations was evaluated with Gini coefficient. Results Between 2005 and 2011, the number of CT, MRI and PET devices in Japan increased by 47% (8789 to 12945), 19% (5034 to 5990) and 70% (274 to 466), respectively. Gini coefficient of the number of devices was largest for PET and smallest for CT (p for PET-MRI difference <0.001; MRI-CT difference <0.001). For all three modalities, Gini coefficient steadily decreased (p for 2011-2005 difference: <0.001 for CT; 0.003 for MRI; and <0.001 for PET). The number of devices in old models (single-detector CT, MRI<1.5 tesla, and conventional PET) decreased, while that in new models (multi-detector CT, MRI >= 1.5 tesla, and PET-CT) increased. Gini coefficient of the old models increased or remained unchanged (increase rate of 9%, 3%, and -1%; p for 2011-2008 difference <0.001, 0.072, and 0.562, respectively), while Gini coefficient of the new models decreased (-10%, -9%, and -10%; p for 2011-2008 difference <0.001, <0.001, and <0.001 respectively). Similar results were observed in terms of utilizations. Conclusions The more abundant a modality, the more equal the modality's distribution. Any increase in the modality made its distribution more equal. The geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force.
  • Soichi Koike, Yuji Furui
    HEALTH POLICY 110 (1) 94 - 100 0168-8510 2013/04 [Refereed][Not invited]
     
    Objectives: The objective of this study was to examine the effects of home-based long-term care insurance services on an increase in care need levels and discuss its policy implications. Methods: We analyzed care need certification and long-term care service use data for 3006 non-institutionalized elderly persons in a Tokyo ward effective as of October 2009 and 2010. Individual care need assessment intervals and their corresponding changes in care need level were calculated from data at two data acquisition points of care need assessment. Those who had been certified but did not use any long-term care insurance service were defined as the control group. The Cox proportionate hazard model was used to determine whether the use of a long-term care insurance service is associated with increased care need level. Results: After adjusting for sex, age, and care need level, the hazard ratio for the probability of increased care need level among service users was calculated as 0.75 (95% confidence interval, 0.64-0.88; p < 0.001). Conclusions: Home-based long-term care service use may prevent an increase in care need level. Administrative data on care need certification and services use could be an effective tool for evaluating the long-term care insurance system. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Seizan Tanabe, Toshio Ogawa, Manabu Akahane, Soichi Koike, Hiromasa Horiguchi, Hideo Yasunaga, Tatsuhiro Mizoguchi, Tetsuo Hatanaka, Hiroyuki Yokota, Tomoaki Imamura
    Journal of Emergency Medicine 44 (2) 389 - 397 0736-4679 2013/02 [Refereed][Not invited]
     
    Background: The effect of prehospital use of supraglottic airway devices as an alternative to tracheal intubation on long-term outcomes of patients with out-of-hospital cardiac arrest is unclear. Study Objectives: We compared the neurological outcomes of patients who underwent supraglottic airway device insertion with those who underwent tracheal intubation. Methods: We conducted a nationwide population-based observational study using a national database containing all out-of-hospital cardiac arrest cases in Japan over a 3-year period (2005-2007). The rates of neurologically favorable 1-month survival (primary outcome) and of 1-month survival and return of spontaneous circulation before hospital arrival (secondary outcomes) were examined. Multiple logistic regression analyses were performed to adjust for potential confounders. Advanced airway devices were used in 138,248 of 318,141 patients, including an endotracheal tube (ETT) in 16,054 patients (12%), a laryngeal mask airway (LMA) in 34,125 patients (25%), and an esophageal obturator airway (EOA) in 88,069 patients (63%). Results: The overall rate of neurologically favorable 1-month survival was 1.03% (1426/137,880). The rates of neurologically favorable 1-month survival were 1.14% (183/16,028) in the ETT group, 0.98% (333/34,059) in the LMA group, and 1.04% (910/87,793) in the EOA group. Compared with the ETT group, the rates were significantly lower in the LMA group (adjusted odds ratio 0.77, 95% confidence interval [CI] 0.64-0.94) and EOA group (adjusted odds ratio 0.81, 95% CI 0.68-0.96). Conclusions: Prehospital use of supraglottic airway devices was associated with slightly, but significantly, poorer neurological outcomes compared with tracheal intubation, but neurological outcomes remained poor overall. (c) 2013 Elsevier Inc.
  • Manabu Akahane, Seizan Tanabe, Toshio Ogawa, Soichi Koike, Hiromasa Horiguchi, Hideo Yasunaga, Tomoaki Imamura
    PEDIATRIC CRITICAL CARE MEDICINE 14 (2) 130 - 136 1529-7535 2013/02 [Refereed][Not invited]
     
    Objectives: There is a paucity of data examining nationwide population-based incidences and outcomes of pediatric out-of-hospital cardiac arrest. The objective of this study is to describe the detailed characteristics of pediatric out-of-hospital cardiac arrest by scholastic age category and to evaluate the impact of bystander cardiopulmonary resuscitation and public access-automated external defibrillators on the 1-month survival and favorable neurological status of pediatric out-of-hospital cardiac arrest patients. Design: A nationwide, population-based, observational study. Setting: Nationwide emergency medical system in Japan. Patients: Out-of-hospital cardiac arrest patients aged <= 18 yr. Measurements and Main Results: We identified 7,624 pediatric out-of-hospital cardiac arrest patients (<= 18 yr old) from a nationwide population-based out-of-hospital cardiac arrest database in Japan from 2005 to 2008 and stratified them into five categories by scholastic age. The overall rates of 1-month survival and favorable neurological outcomes were 11.0% and 5.1%, respectively. Bystander cardiopulmonary resuscitation resulted in a significant improvement in both 1-month survival (odds ratio 2.81; 95% confidence interval 2.30-3.44) and favorable neurological outcomes (odds ratio 4.55; 95% confidence interval 3.35-6.18). Performing public access-automated external defibrillators had a significant effect on the 1-month survival rate (odds ratio 3.51; 95% confidence interval 1.81-6.81) and favorable neurological outcomes (odds ratio 5.13; 95% confidence interval 2.64-9.96). Conclusions: This study demonstrated that bystander cardiopulmonary resuscitation and public access-automated external defibrillators had a significant impact on the outcomes of pediatric out-of-hospital cardiac arrest. The improved survival associated with bystander cardiopulmonary resuscitation and public access-automated external defibrillators are clinically important and are of major public health importance for school-aged out-of-hospital cardiac arrest patients. (Pediatr Crit Care Med 2013; 14:130-136)
  • Seizan Tanabe, Hideo Yasunaga, Soichi Koike, Manabu Akahane, Toshio Ogawa, Hiromasa Horiguchi, Tetsuo Hatanaka, Hiroyuki Yokota, Tomoaki Imamura
    Critical care (London, England) 16 (6) R219  1364-8535 2012/11 [Refereed][Not invited]
     
    INTRODUCTION: Conventional monophasic defibrillators for out-of-hospital cardiac-arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for pediatric out-of-hospital cardiac-arrest patients remains unknown. This study aimed to compare the survival outcomes of pediatric out-of-hospital cardiac-arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. METHODS: This prospective, nationwide, population-based observational study included pediatric out-of-hospital cardiac-arrest patients from January 1, 2005, to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurologic impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. RESULTS: Among 5,628 pediatric out-of-hospital cardiac-arrest patients (1 through 17 years old), 430 who received defibrillation shock with monophasic or biphasic defibrillator were analyzed. The number of patients who received defibrillation shock with monophasic defibrillator was 127 (30%), and 303 (70%) received defibrillation shock with biphasic defibrillator. The survival rates at 1 month with minimal neurologic impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchic logistic regression analyses by using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurologic impairment (odds ratio (OR), 1.57; 95% confidence interval (CI), 0.87 to 2.83; P = 0.14) and 1-month survival (OR, 1.38; 95% CI, 0.87 to 2.18; P = 0.17). CONCLUSIONS: The present nationwide population-based observational study could not confirm an advantage of biphasic over monophasic defibrillators for pediatric OHCA patients.
  • Manabu Akahane, Seizan Tanabe, Soichi Koike, Toshio Ogawa, Hiromasa Horiguchi, Hideo Yasunaga, Tomoaki Imamura
    International journal of emergency medicine 5 (1) 41 - 41 1865-1372 2012/11 [Refereed][Not invited]
     
    UNLABELLED: BACKGROUND: A growing elderly population along with advances in equipment and approaches for pre-hospital resuscitation necessitates up-to-date information when developing policies to improve elderly out-of-hospital cardiac arrest (OHCA) outcomes. We examined the effects of bystander type (family or non-family) intervention on 1-month outcomes of witnessed elderly OHCA patients. METHODS: Data from a total of 85,588 witnessed OHCA events in patients aged ≥65 years, which occurred from 2005 to 2008, were obtained from a nationwide population-based database. Patients were stratified into three age categories (65-74, 75-84, ≥85 years), and the effects of bystander type (family or non-family) on initial cardiac rhythm, rate of bystander cardiopulmonary resuscitation (CPR), and 1-month outcomes were assessed. RESULTS: The overall survival rate was 6.9% (65-74 years: 9.8%, 75-84 years: 6.9%, ≥85 years: 4.6%). Initial VF/VT was recorded in 11.1% of cases with a family bystander and 12.9% of cases with a non-family bystander. The rate of bystander CPR was constant across the age categories in patients with a family bystander and increased with advancing age categories in patients with a non-family bystander. Patients having a non-family bystander were associated with significantly higher 1-month rates of survival (OR: 1.26; 95% CI: 1.19-1.33) and favorable neurological status (OR: 1.47; 95% CI: 1.34-1.60). CONCLUSIONS: Elderly patient OHCA events witnessed by a family bystander were associated with worse 1-month outcomes than those witnessed by a non-family bystander. Healthcare providers should consider targeting potential family bystanders for CPR education to increase the rate and quality of bystander CPR.
  • Seizan Tanabe, Hideo Yasunaga, Toshio Ogawa, Soichi Koike, Manabu Akahane, Hiromasa Horiguchi, Tetsuo Hatanaka, Hiroyuki Yokota, Tomoaki Imamura
    CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES 5 (5) 689 - 696 1941-7705 2012/09 [Refereed][Not invited]
     
    Background-The use and popularity of the biphasic waveform defibrillator as a replacement for the monophasic waveform defibrillator are increasing, but it is unclear whether this can improve the rate of survival among out-of-hospital cardiac arrest patients. This study aimed to verify the hypothesis that the outcome of out-of-hospital cardiac arrest patients who received defibrillation shock with the biphasic waveform defibrillator was better than that of patients who received defibrillation shock with the monophasic defibrillator. Methods and Results-This prospective, nationwide, population-based, observational study included 21 172 out-of-hospital cardiac arrest patients with initial ventricular fibrillation or pulseless ventricular tachycardia from January 1, 2005, through December 31, 2007. Defibrillation shock was performed by monophasic defibrillator on 8224 (39%) patients and by biphasic defibrillator on 12 948 (61%) patients. The rate of survival at 1 month with minimal neurological impairment was 11.6% (951/8192) in the monophasic defibrillator group and 12.8% (1653/12928) in the biphasic defibrillator group. Hierarchical logistic regression analysis using a generalized estimation equation showed no significant difference between the biphasic and monophasic groups in 1-month survival with minimal neurological impairment (adjusted odds ratio, 1.07; 95% confidence interval, 0.91-1.26; P=0.42). Confirmatory propensity score analyses showed similar results. Conclusions-Although monophasic defibrillators are being replaced by biphasic defibrillators, our nationwide population-based observational study failed to demonstrate a statistically significant association between defibrillation waveform and 1-month survival rate with minimal neurological impairment. (Circ Cardiovasc Qual Outcomes. 2012;5:689-696.)
  • Tomoko Kodama, Soichi Koike, Shinya Matsumoto, Hiroo Ide, Hideo Yasunaga, Tomoaki Imamura
    HEALTH POLICY 105 (2-3) 214 - 220 0168-8510 2012/05 [Refereed][Not invited]
     
    Background: The percentage of females in the physician workforce is increasing in Japan, as in other countries: however, the working status of female physicians has not been sufficiently investigated. Methods: Original data were obtained from the National Survey of Physicians (NSP) conducted by the Ministry of Health. Labour and Welfare, Japan, from 1984 to 2004. We examined the trend of female physicians' areas of practice and analyzed their leave, return to work, and change in areas of practice using cohort data. Results: The percentage of female physicians has increased significantly in recent generations, especially in surgery, surgical subareas of practice, and obstetrics and gynecology. A remarkable increase was found in obstetrics and gynecology among women under 29 years old from 15.4 to 66.2%. The total number of female physicians on leave has been higher than the number of female physicians returning since 1998. The average percentage of those who changed their area of practice was high in surgery (20.7%) and low in pediatrics (5.0%) and obstetrics and gynecology (1.7%). Conclusions: A strategic plan is needed for future health policy to plan for the physician workforce, especially for the areas of practice with increasing proportions of young female physicians. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • Manabu Akahane, Toshio Ogawa, Seizan Tanabe, Soichi Koike, Hiromasa Horiguchi, Hideo Yasunaga, Tomoaki Imamura
    CRITICAL CARE MEDICINE 40 (5) 1410 - 1416 0090-3493 2012/05 [Refereed][Not invited]
     
    Objective: Most previous studies of pediatric out-of-hospital cardiac arrest have typically examined relatively small datasets from small study regions. Although several studies have reported the impact on adult out-of-hospital cardiac arrest, little information is available on the impact of telephone dispatcher assistance on the outcomes of pediatric out-of-hospital cardiac arrest. We set out to examine the impact of cardiopulmonary resuscitation instruction by telephone dispatcher on the outcomes of pediatric out-of-hospital cardiac arrest. Design: Population-based, observational study. Setting: Japan-wide population-based setting. Patients: We identified 1,780 pediatric out-of-hospital cardiac arrest patients (67.8% male) with witnessed collapse from a nationwide, population-based, out-of-hospital cardiac arrest database. Intervention: None. Measurement and Main Results: We assessed the impact of telephone dispatcher assistance on the outcomes of 1-month survival rates and favorable neurologic status among the groups. The overall rate of bystander-performed chest compression and mouth-to-mouth ventilation among the witnessed pediatric out-of-hospital cardiac arrests were 39.5% and 25.6%, respectively. Telephone dispatcher assistance was offered in 28.4% of the witnessed pediatric out-of-hospital cardiac arrest cases and resulted in a significant increase in both chest compression (adjusted odds ratio 6.04; 95% confidence interval 4.72-7.72) and mouth-to-mouth ventilation (adjusted odds ratio 3.10; 95% confidence interval 2.44-3.95), and a significant improvement in 1-month survival rate (adjusted odds ratio 1.46; 95% confidence interval 1.05-2.03), but no significant effect on favorable neurologic outcomes at 1 month (adjusted odds ratio 1.15; 95% confidence interval 0.70-1.88). Potential confounding factors included age categories, sex, bystander type, cause of cardiac arrest, bystander cardiopulmonary resuscitation, and attempted defibrillation. Conclusions: Telephone dispatcher assistance could significantly increase bystander cardiopulmonary resuscitation among witnessed pediatric out-of-hospital cardiac arrests. Although there was only a small, nonsignificant effect on the improvement in favorable neurologic outcome at 1 month, the improved survival associated with telephone dispatcher assistance in pediatric out-of-hospital cardiac arrest is clinically important, and is of major public health importance. In cases where cardiac arrest was uncertain from the bystander's replies during the call to emergency medical services, telephone dispatcher assistance was not offered, which could affect the adjusted odds ratio of the present study. (Crit Care Med 2012; 40: 1410-1416)
  • Soichi Koike, Hiroo Ide, Tomoko Kodama, Shinya Matsumoto, Hideo Yasunaga, Tomoaki Imamura
    ACADEMIC MEDICINE 87 (5) 662 - 667 1040-2446 2012/05 [Refereed][Not invited]
     
    Purpose To investigate career trends for physician-scientists in Japan. Method The authors analyzed 1996-2008 biennial census survey data from Japan's national physician registry to examine trends over time in the numbers and proportion of physician-scientists by sex and years since registration. They also analyzed the transition of registered physicians into and out of the physician-consecutive surveys (1996-1998 and 2006-2008). Results The number of physician-scientists between 1996 and 2008 was stable, with a low of 4,893 and a high of 5,325. The number of younger physician-scientists (those registered 0-4 years at the time of the surveys) declined sharply, however, from 828 in 1996 to 253 in 2008. The number of female physician-scientists increased from 528 in 1996 to 746 in 2008. Across the two survey periods, about 30% of physician-scientists left the career path, but this attrition was offset by about the same number of new individuals entering the field. Conclusions Although the total number of physician-scientists was relatively unchanged during the period studied, it is essential that educators and policy makers develop approaches to address underlying demographic changes to ensure an adequate age- and gender-balanced
  • Satoshi Ezoe, Takeo Morooka, Tatsuya Noda, Miriam Lewis Sabin, Soichi Koike
    PLOS ONE 7 (1) 1932-6203 2012/01 [Refereed][Not invited]
     
    Background: Men who have sex with men (MSM) are one of the groups most at risk for HIV infection in Japan. However, size estimates of MSM populations have not been conducted with sufficient frequency and rigor because of the difficulty, high cost and stigma associated with reaching such populations. This study examined an innovative and simple method for estimating the size of the MSM population in Japan. We combined an internet survey with the network scale-up method, a social network method for estimating the size of hard-to-reach populations, for the first time in Japan. Methods and Findings: An internet survey was conducted among 1,500 internet users who registered with a nationwide internet-research agency. The survey participants were asked how many members of particular groups with known population sizes (firepersons, police officers, and military personnel) they knew as acquaintances. The participants were also asked to identify the number of their acquaintances whom they understood to be MSM. Using these survey results with the network scale-up method, the personal network size and MSM population size were estimated. The personal network size was estimated to be 363.5 regardless of the sex of the acquaintances and 174.0 for only male acquaintances. The estimated MSM prevalence among the total male population in Japan was 0.0402% without adjustment, and 2.87% after adjusting for the transmission error of MSM. Conclusions: The estimated personal network size and MSM prevalence seen in this study were comparable to those from previous survey results based on the direct-estimation method. Estimating population sizes through combining an internet survey with the network scale-up method appeared to be an effective method from the perspectives of rapidity, simplicity, and low cost as compared with more-conventional methods.
  • Seizan Tanabe, Hideo Yasunaga, Soichi Koike, Manabu Akahane, Toshio Ogawa, Hiromasa Horiguchi, Tetsuo Hatanaka, Hiroyuki Yokota, Tomoaki Imamura
    CRITICAL CARE 16 (6) 1466-609X 2012 [Refereed][Not invited]
     
    Introduction: Conventional monophasic defibrillators for out-of-hospital cardiac-arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for pediatric out-of-hospital cardiac-arrest patients remains unknown. This study aimed to compare the survival outcomes of pediatric out-of-hospital cardiac-arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. Methods: This prospective, nationwide, population-based observational study included pediatric out-of-hospital cardiac-arrest patients from January 1, 2005, to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurologic impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. Results: Among 5,628 pediatric out-of-hospital cardiac-arrest patients (1 through 17 years old), 430 who received defibrillation shock with monophasic or biphasic defibrillator were analyzed. The number of patients who received defibrillation shock with monophasic defibrillator was 127 (30%), and 303 (70%) received defibrillation shock with biphasic defibrillator. The survival rates at 1 month with minimal neurologic impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchic logistic regression analyses by using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurologic impairment (odds ratio (OR), 1.57; 95% confidence interval (CI), 0.87 to 2.83; P = 0.14) and 1-month survival (OR, 1.38; 95% CI, 0.87 to 2.18; P = 0.17). Conclusions: The present nationwide population-based observational study could not confirm an advantage of biphasic over monophasic defibrillators for pediatric OHCA patients.
  • Soichi Koike, Seizan Tanabe, Toshio Ogawa, Manabu Akahane, Hideo Yasunaga, Hiromasa Horiguchi, Shinya Matsumoto, Tomoaki Imamura
    RESUSCITATION 82 (7) 863 - 868 0300-9572 2011/07 [Refereed][Not invited]
     
    Aim: We sought to examine whether the outcomes of out-of-hospital cardiopulmonary arrest (OHCA) patients differed between weekday and weekend/holiday admissions, or between daytime and nighttime admissions. Methods: From a national registry of OHCA events in Japan between 2005 and 2008, 173,137 cases where the call-to-hospital admission interval was shorter than 120 min and collapse was witnessed by a bystander were included in this study. One-month survival rate and neurologically favourable 1-month survival rate were used as outcome measures. Logistic regression was used to adjust for potential confounding factors. Results: No significant differences in outcome were found between weekday and holiday/weekend admissions in rates of 1-month survival or neurologically favourable 1-month survival (p = 0.78 and p = 0.80, respectively). In contrast, patients admitted in the daytime exhibited significantly better outcomes than those admitted at night, on both outcome measures (p < 0.001 and p < 0.001). After adjusting for possible confounding factors, outcomes were significantly better for daytime admissions, with odds ratios of 1.26 (95% confidence interval (CI) 1.22-1.31; p < 0.001) for 1-month survival, and 1.26 (95% CI 1.20-1.32; p < 0.001) for neurologically favourable 1-month survival. In contrast, no significant differences on either outcome measure were found between weekday and weekend/holiday cases, with odds ratios of 1.00 (95% CI 0.96-1.04; p = 0.96) for 1-month survival and 0.99 (95% CI 0.94-1.04; p = 0.78) for neurologically favourable 1-month survival. Conclusions: Even after adjusting for confounding factors, admission day (weekday vs. weekend/holiday) had no effect on 1-month survival or neurologically favourable 1-month survival. In contrast, daytime admission was associated with significantly better outcomes than nighttime admissions. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • Soichi Koike, Seizan Tanabe, Toshio Ogawa, Manabu Akahane, Hideo Yasunaga, Hiromasa Horiguchi, Shinya Matsumoto, Tomoaki Imamura
    PREHOSPITAL EMERGENCY CARE 15 (3) 393 - 400 1090-3127 2011/07 [Refereed][Not invited]
     
    Objectives. This study aimed to determine whether short cardiopulmonary resuscitation (CPR) by emergency medical services before defibrillation (CPR first) has a better outcome than immediate defibrillation followed by CPR (shock first) in patients with ventricular fibrillation/pulseless ventricular tachycardia (VF/pulseless VT) out-of-hospital cardiac arrest. Methods. We analyzed a national database between 2006 and 2008, and included patients aged 18 years or more who had witnessed cardiac arrests and whose first recorded rhythm was VF/pulseless VT. Those study subjects were divided into five groups in accordance with the CPR/defibrillation intervention sequence. Each group was subdivided into call-to-response intervals of < 5 minutes and >= a parts per thousand yen5 minutes. We identified 267 patients in the shock-first group and 6,407 patients in the CPR-first group. One-month survival and neurologically favorable one-month survival rates were used for outcome measures. The association of intervention type on outcomes (one-month survival or neurologically favorable one-month survival) was analyzed using multivariate logistic regression analyses by adjusting potential confounding factors such as survey year, gender, age (years), bystander CPR, intubation, and call-to-response interval (min). Results. The overall one-month survival rate was 26.2%% (3,125/11,941) and the neurologically favorable one-month survival rate was 16.6%% (1,983/11,934). The CPR-first group had a one-month survival rate of 27.8%% (1,780/6,407) and a neurologically favorable one-month survival rate of 17.8%% (1,140/6,404), and the shock-first group had survival rates of 24.7%% (66/267) and 18.4%% (49/267), respectively. There were no significant differences in one-month survival and neurologically favorable one-month survival in these two primary comparison groups (odds ratio [[95%% confidence interval]], 0.85 [[0.64--1.13]] and 1.04 [[0.76--1.42]], respectively). Logistic regression analysis showed that neither CPR first nor shock first was associated with the rate of one-month survival or neurologically favorable one-month survival, after adjusting for potential confounders. Conclusions. In our study, CPR prior to attempted defibrillation did not present a better outcome compared with shock first as measured by either one-month survival or neurologically favorable one-month survival, after adjusting for potential confounders. Further studies are required to determine whether CPR first has an advantage over shock first.
  • Manabu Akahane, Toshio Ogawa, Soichi Koike, Seizan Tanabe, Hiromasa Horiguchi, Tatsuhiro Mizoguchi, Hideo Yasunaga, Tomoaki Imamura
    AMERICAN JOURNAL OF MEDICINE 124 (4) 325 - 333 0002-9343 2011/04 [Refereed][Not invited]
     
    OBJECTIVE: We examined the effects of sex on out-of-hospital cardiac arrest outcomes. There is evidence that women are more likely to survive cardiac arrest than men. However, few large studies have examined these sex differences in detail. It is unknown whether the female survival advantage is age-specific or whether sex affects neurologic outcomes after cardiac arrest events. METHODS: Data were analyzed from a nationwide population-based out-of-hospital cardiac arrest database (between January 2005 and December 2007) involving 318,123 patients (male: 188,357, female: 129,766) to assess the effects of sex on out-of-hospital cardiac arrest outcomes in Japan. We selected 276,590 patients aged 20 to 89 years with out-of-hospital cardiac arrest and compared the frequencies of initial cardiac rhythms, 1-month survival rates, and favorable neurologic outcome rates between sexes. RESULTS: The incidence of out-of-hospital cardiac arrest was higher in men than in women (men: 0.12%; women: 0.07%). Men were witnessed more often while out-of-hospital cardiac arrest was occurring (men: 42.1% and women: 36.9%), typically presented with initial ventricular fibrillation/ventricular tachycardia rhythms, and had a higher 1-month survival rate overall after out-of-hospital cardiac arrest events (men: 5.2% and women: 4.3%). However, the rate of survival with a favorable neurologic outcome for women aged 30 to 49 years was significantly higher than that for men within the same age range. Among patients initially presenting with ventricular fibrillation/ventricular tachycardia, the rate of survival with favorable neurologic outcome was higher for women than men in the group aged 40 to 59 years. CONCLUSION: Our results suggest that men have a higher 1-month survival rate after out-of-hospital cardiac arrest because of a higher frequency of ventricular fibrillation/ventricular tachycardia presentation compared with women. Although patients of both sexes with out-of-hospital cardiac arrest initially presenting with ventricular fibrillation/ventricular tachycardia exhibited similar overall survival rates, the rate of survival with favorable neurologic outcome was significantly higher for women than men in the group aged 40 to 59 years. (C) 2011 Elsevier Inc. All rights reserved. The American Journal of Medicine (2011) 124, 325-333
  • Hideo Yasunaga, Hiroaki Miyata, Hiromasa Horiguchi, Seizan Tanabe, Manabu Akahane, Toshio Ogawa, Soichi Koike, Tomoaki Imamura
    INTERNATIONAL JOURNAL OF HEALTH GEOGRAPHICS 10 26  1476-072X 2011/04 [Refereed][Not invited]
     
    Background: Little is known about the effects of geographic variation on outcomes of out-of-hospital cardiac arrest (OHCA). The present study investigated the relationship between population density, time between emergency call and ambulance arrival, and survival of OHCA, using the All-Japan Utstein-style registry database, coupled with geographic information system (GIS) data. Methods: We examined data from 101,287 bystander-witnessed OHCA patients who received emergency medical services (EMS) through 4,729 ambulatory centers in Japan between 2005 and 2007. Latitudes and longitudes of each center were determined with address-match geocoding, and linked with the Population Census data using GIS. The endpoints were 1-month survival and neurologically favorable 1-month survival defined as Glasgow-Pittsburgh cerebral performance categories 1 or 2. Results: Overall 1-month survival was 7.8%. Neurologically favorable 1-month survival was 3.6%. In very low-density (<250/km(2)) and very high-density(>= 10,000/km(2)) areas, the mean call-response intervals were 9.3 and 6.2 minutes, 1-month survival rates were 5.4% and 9.1%, and neurologically favorable 1-month survival rates were 2.7% and 4.3%, respectively. After adjustment for age, sex, cause of arrest, first aid by bystander and the proportion of neighborhood elderly people >= 65 yrs, patients in very high-density areas had a significantly higher survival rate (odds ratio (OR), 1.64; 95% confidence interval (CI), 1.44 - 1.87; p < 0.001) and neurologically favorable 1-month survival rate (OR, 1.47; 95% CI, 1.22 - 1.77; p < 0.001) compared with those in very low-density areas. Conclusion: Living in a low-density area was associated with an independent risk of delay in ambulance response, and a low survival rate in cases of OHCA. Distribution of EMS centers according to population size may lead to inequality in health outcomes between urban and rural areas.
  • Toshio Ogawa, Manabu Akahane, Soichi Koike, Seizan Tanabe, Tatsuhiro Mizoguchi, Tomoaki Imamura
    BMJ 342 (7792) 321  1756-1833 2011/02 [Refereed][Not invited]
     
    Objective: To compare the effectiveness of cardiopulmonary resuscitation (CPR) with chest compression only and conventional CPR on outcomes after cardiopulmonary arrest out of hospital. Design: Nationwide population based observational study. Setting: A nationwide emergency medical service system in Japan. Population: All consecutive patients with out of hospital cardiopulmonary arrest, January 2005 to December 2007 in Japan, witnessed at the moment of collapse. Lay people attempted chest compression only CPR (n=20 707) or conventional CPR (mouth to mouth ventilation and chest compression) (n=19 328), and patients were transferred to hospital by ambulance. Main outcome measures: Factors associated with better outcomes (assessed with X2, multiple logistic regression analysis, odds ratios and their 95% confidence intervals): one month survival and neurologically favourable one month survival rates defined as category one (good cerebral performance) or two (moderate cerebral disability) of the cerebral performance categories. Results: Conventional CPR was associated with better outcomes than chest compression only CPR, for both one month survival (adjusted odds ratio 1.17, 95% confidence interval 1.06 to 1.29) and neurologically favourable one month survival (1.17, 1.01 to 1.35). Neurologically favourable one month survival decreased with increasing age and with delays of up to 10 minutes in starting CPR for both conventional and chest compression only CPR. The benefit of conventional CPR over chest compression only CPR was significantly greater in younger people in non-cardiac cases (P=0.025) and with a delay in start of CPR after the event was witnessed in non-cardiac cases (P=0.015) and all cases combined (P=0.037). Conclusions: Conventional CPR is associated with better outcomes than chest compression only CPR for selected patients with out of hospital cardiopulmonary arrest, such as those with arrests of non-cardiac origin and younger people, and people in whom there was delay in the start of CPR.
  • Soichi Koike, Toshio Ogawa, Senzan Tanabe, Shinya Matsumoto, Manabu Akahane, Hideo Yasunaga, Hiromasa Horiguchi, Tomoaki Imamura
    Critical care (London, England) 15 (3) R120  1364-8535 2011 [Refereed][Not invited]
     
    INTRODUCTION: The relationship between collapse to emergency medical service (EMS) cardiopulmonary resuscitation (CPR) interval and outcome has been well documented. However, most studies have only analyzed cases of cardiac origin and Vf (ventricular fibrillation)/pulseless VT (ventricular tachycardia). We sought to examine all causes of cardiac arrest and analyze the relationship between collapse-to-EMS CPR interval and outcome in a nationwide sample using an out-of-hospital cardiac arrest (OHCA) registry. METHODS: This was a retrospective observational study based on a nationwide OHCA patient registry in Japan between 2005 and 2008 (n = 431,968). We included cases where collapse was witnessed by a bystander and where collapse and intervention time were recorded (n = 109,350). Data were collected based on the Utstein template. One-month survival and neurologically favorable one-month survival were used as outcome measures. Logarithmic regression and logistic regression were used to examine the relation between outcomes and collapse-to-EMS CPR interval. RESULTS: Among collapse-to-EMS CPR intervals between 3 and 30 minutes, the logarithmic regression equation for the relationship with one-month survival was y = -0.059 ln(x) + 0.21, while that for the relationship with neurologically favorable one-month survival was y = -0.041 ln(x) + 0.13. After adjusting for potential confounders in the logistic regression analysis for all intervals, longer collapse-to-EMS CPR intervals were associated with lower rates of one-month survival (odds ratio (OR) 0.93, 95% confidence interval (CI): 0.93 to 0.93) and neurologically favorable one-month survival (OR 0.89, 95% CI 0.89 to 0.90). CONCLUSIONS: Improving the emergency medical system and CPR in cases of OHCA is important for improving the outcomes of OHCA.
  • Soichi Koike, Shinya Matsumoto, Tomoko Kodama, Hiroo Ide, Hideo Yasunaga, Tomoaki Imamura
    HEALTH POLICY 98 (2-3) 236 - 244 0168-8510 2010/12 [Refereed][Not invited]
     
    Objectives: To investigate trends of specialty distribution and physicians' career paths in Japan, and to discuss potential policy implications. Methods: Distribution of main area of practice, relation between board-certified specialists and reported main area of practice, and migration of main area of practice by career stage were analyzed in data from the National Physician Survey, collected between 1996 and 2006. Results: The percentages of physicians involved in internal medicine, surgery, neurosurgery, pediatrics, ophthalmology, obstetrics and gynecology and otorhinolaryngology decreased from 1996 to 2006. Overall, the numbers reported for the main area of practice matched the number of board-certified specialists. Among physicians who began their careers as internal medicine physicians in the 1996 registration cohort, the proportion of those engaged in internal medicine fell from 82.5% in 1996, to 43.6% in 2000, to 37.0% by their 10th year. Among five registration cohorts analyzed, 9.1-16.8% of the surgical specialties group switched their main area of practice to internal medicine within 10 years. Conclusions: While there is a general trend toward specialization, it is important to balance between general practice and specialization to strengthen health care systems. Developing a certification system and maintaining the quality of specialist physicians are also crucial. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
  • Hiroo Ide, Soichi Koike, Hideo Yasunaga, Tomoko Kodama, Kazuhiko Ohe, Tomoaki Imamura
    WORLD JOURNAL OF SURGERY 34 (8) 1748 - 1755 0364-2313 2010/08 [Refereed][Not invited]
     
    A surgical workforce is essential for providing surgical services to the community. However, little is known about surgeons' career changes in circumstances where physicians can freely choose their specialty. Differing career transitions among surgical specialties were hypothesized. Longitudinal data were obtained for all physicians in Japan, giving a total of 4,302,844 items of data (for 390,368 physicians) from 1972 to 2006. Descriptive statistics for all physicians and surgeons were calculated in 1976, 1986, 1996, and 2006. "Active surgeons" (working at hospitals), "primary care surgeons" (working at clinics), and "retired surgeons" were analyzed among physicians licensed in 1972, 1982, and 1992 for the subspecialties of general surgery, orthopedic surgery, neurosurgery, urology, and "other" surgeries. Survival analysis and Cox's proportional hazard analysis were conducted to examine factors affecting career changes. During the study period, the greatest change was observed in the increased number of surgeons per 100,000 physicians. The percentage of female surgeons and surgeons registered in a surgical subspecialty also increased greatly. Significant differences, by sex, age, and subspecialty, were shown in survival analyses for surgeons' career changes in the transition from active surgeons to primary care surgeons or retired surgeons. Surgical specialty was still a significant factor for predicting career transition, even after adjustment for the surgeons' characteristics. The current study elucidated the differences in career transitions among surgical specialties. Given the observed findings, policy makers should consider more detailed and effective measures for retaining surgeons in active practice.
  • Soichi Koike, Tomoko Kodama, Shinya Matsumoto, Hiroo Ide, Hideo Yasunaga, Tomoaki Imamura
    BMC HEALTH SERVICES RESEARCH 10 101  1472-6963 2010/04 [Refereed][Not invited]
     
    Background: Physicians who serve as public health specialists at public health centers and health departments in local or central government have significant roles because of their public health expertise. The aim of this study is to analyze the retention and career paths of such specialists in Japan. Method: We analyzed the data of seven consecutive surveys, spanning 1994 to 2006. We first analyzed the 2006 survey data by sex, age group, and facility type. We then examined the changes over time in the proportion of physicians working in public health administration agencies. We also examined the distribution of the facility types and specialties in which physicians worked both before beginning and after leaving their jobs. These analyses were performed by using physician registration numbers to cross-link data from two consecutive surveys. Results: The proportion of physicians working in public health administration agencies was 0.7% in 2006. The actual numbers for each survey ranged between 1,800 and 1,900. The overall rate remaining in public health administration agencies during the two-year survey interval was 72.8% for 1994-1996. The ratio declined to 67.2% for 2004-2006. Among younger physicians with 1-10 years of experience, the retention rate showed a sharp decline, dropping from 72.6% to 50.0%. Many of these physicians came from or left for a hospital position, with the proportion entering academic hospital institutions increasing in recent years. In many cases, physicians left or entered internal medicine clinical practices. Conclusion: At present in Japan, the number of physicians who leave and the number who begin a position are almost the same; thus, some of the problems associated with physicians leaving are yet to become apparent. However, the fact that the retention period is shortening for younger physicians may represent a future problem for ensuring the quality of physicians in public health administration agencies. Possible strategies include: increasing the number of physicians entering positions; reducing the number leaving positions; and creating a system where physicians can easily reenter positions after leaving while also establishing a revolving door type of career development system, involving both public health departments and hospital clinical departments.
  • Soichi Koike, Hiroo Ide, Hideo Yasunaga, Tomoko Kodama, Shinya Matsumoto, Tomoaki Imamura
    MEDICAL EDUCATION 44 (3) 289 - 297 0308-0110 2010/03 [Refereed][Not invited]
     
    Objectives This study analyses and discusses recent changes in young Japanese doctors' career paths, in terms of their distribution in different types of facilities and specialties, following changes to the postgraduate clinical training system in 2004. Methods Data from the National Survey of Physicians, Dentists and Pharmacists conducted by Japan's Ministry of Health, Labour and Welfare were used for this study. Results After the introduction of the new postgraduate training system, 2 years of clinical training became mandatory and a doctor-to-facility matching system was introduced. Since then, more young doctors have migrated from academic hospitals to non-academic hospitals. The number of first-year doctors at non-academic hospitals increased, whereas the number at academic hospitals decreased. In terms of the distribution of doctors per specialty, the decreasing tendency of doctors to choose internal medicine and surgery has accelerated. These results illustrate the significant changes that have affected young doctors' career paths since the new system was introduced. Conclusions Designing and providing desirable postgraduate clinical training and achieving appropriate doctor distribution are important policy issues. Appropriate policy interventions regarding a mechanism to ensure the appropriate distribution of doctors should be established and attention should be paid to expanding doctors' choices and increasing patient satisfaction and general cost-effectiveness.
  • Hideo Yasunaga, Hiromasa Horiguchi, Seizan Tanabe, Manabu Akahane, Toshio Ogawa, Soichi Koike, Tomoaki Imamura
    CRITICAL CARE 14 (6) 1466-609X 2010 [Refereed][Not invited]
     
    Introduction: There are inconsistent data about the effectiveness of prehospital physician-staffed advanced cardiac life support (ACLS) on the outcomes of out-of-hospital cardiac arrest (OHCA). Furthermore, the relative importance of bystander-initiated cardiopulmonary resuscitation (BCPR) and ACLS and the effectiveness of their combination have not been clearly demonstrated. Methods: Using a prospective, nationwide, population-based registry of all OHCA patients in Japan, we enrolled 95,072 patients whose arrests were witnessed by bystanders and 23,127 patients witnessed by emergency medical service providers between 2005 and 2007. We divided the bystander-witnessed arrest patients into Group A (ACLS by emergency life-saving technicians without BCPR), Group B (ACLS by emergency life-saving technicians with BCPR), Group C (ACLS by physicians without BCPR) and Group D (ACLS by physicians with BCPR). The outcome data included 1-month survival and neurological outcomes determined by the cerebral performance category. Results: Among the 95,072 bystander-witnessed arrest patients, 7,722 (8.1%) were alive at 1 month, including 2,754 (2.9%) with good performance and 3,171 (3.3%) with vegetative status or worse. BCPR occurred in 42% of bystander-witnessed arrests. In comparison with Group A, the rates of good-performance survival were significantly higher in Group B (odds ratio (OR), 2.23; 95% confidence interval, 2.05 to 2.42; P < 0.01) and Group D (OR, 2.80; 95% confidence interval, 2.28 to 3.43; P < 0.01), while no significant difference was seen for Group C (OR, 1.18; 95% confidence interval, 0.86 to 1.61; P = 0.32). The occurrence of vegetative status or worse at 1 month was highest in Group C (OR, 1.92; 95% confidence interval, 1.55 to 2.37; P < 0.01). Conclusions: In this registry-based study, BCPR significantly improved the survival of OHCA with good cerebral outcome. The groups with BCPR and ACLS by physicians had the best outcomes. However, receiving ACLS by physicians without preceding BCPR significantly increased the number of patients with neurologically unfavorable outcomes.
  • Shinya Matsumoto, Yoshiyuki Kanagawa, Soichi Koike, Manabu Akahane, Hiroshi Uchi, Satoko Shibata, Masutaka Furue, Tomoaki Imamura
    BMC Research Notes 3 129  1756-0500 2010 [Refereed][Not invited]
     
    Background. Recently, methods for measurement of dioxins in the blood have improved. Also, techniques for analyzing large quantities of data have been developed, such as data mining. Even in subjects with elusive characteristics, it is becoming possible to find previously unknown characteristics by checking all combinations of symptoms. Findings. Using association analysis of the data mining technique, we extracted and compared combinations with a strong relationship between recent symptoms (2001-2004) and recent blood PeCDF levels, and between past symptoms (1986-1989) and recent PeCDF levels, in physical, blood, dermatological, dental and ophthalmological examinations. Patients with a higher PeCDF level were more likely to present with symptoms included in the diagnostic criteria, such as pigmentation. In addition, we obtained evidence that recent PeCDF levels had a stronger relationship with recent than past symptoms. Conclusions. Recent PeCDF levels should not be compared directly with past symptoms. However, as the excretion rate of PeCDF has been constant, it is probable that PeCDF levels were higher in the past if recent PeCDF levels were also high. The study confirmed a relationship between past PeCDF levels and past clinical symptoms. For symptoms included in the diagnostic criteria, there was a stronger relationship between PeCDF levels and past symptoms than recent symptoms. Alleviation of symptoms in each patient or aging weakened the relationship between PeCDF levels and symptoms. © 2010 Matsumoto et al licensee BioMed Central Ltd.
  • Soichi Koike, Tomoko Kodama, Shinya Matsumoto, Hiroo Ide, Hideo Yasunaga, Tomoaki Imamura
    MEDICAL TEACHER 32 (6) E239 - E247 0142-159X 2010 [Refereed][Not invited]
     
    Background: In 2004, a new postgraduate medical training system was introduced in Japan and a shift of new graduates from university hospitals to other postgraduate education hospitals happened. Aim: The aim of this study is to analyse the past trends on postgraduate medical education choices and subsequent career options to discuss possible outcomes of the current shift and policy implications. Methods: Data from the national physician survey from 1976 to 2006 were analysed. The proportion change of physicians started their career in university hospitals was calculated. The career paths for physicians by different residency type were presented. Results: More than 90% of physicians experienced university hospital work at least once in their 20-year careers. In their first 10 years of their career, physicians who started their residency in a university hospital tended to spend more years working in university hospitals, and those who started in other post-graduate training hospitals tended to spend less in university hospitals. Then, these groups presented quite similar patterns in their career choices. Conclusions: University hospitals need to strengthen their function as continuing education and career development centres and to adopt a less paternalistic approach, as fewer residents start their career in university hospitals.
  • Hiroo Ide, Hideo Yasunaga, Soichi Koike, Tomoko Kodama, Takashi Igarashi, Tomoaki Imamura
    PEDIATRICS INTERNATIONAL 51 (5) 645 - 649 1328-8067 2009/10 [Refereed][Not invited]
     
    Background: Currently, there is a shortage of hospital pediatricians in Japan. In the present study, using data from the Survey of Physicians, Dentists, and Pharmacists in Japan, we analyzed the dynamics and distribution of pediatricians, using a time series approach. Methods: The total number of pediatricians, the ratios of hospital-working and female pediatricians, their mean age and geographic distribution in 1974, 1984, 1994, and 2004 were determined. The dynamics of pediatricians were analyzed by identifying the annual number of physicians participating in and withdrawing from pediatrics, and by following up withdrawal rates from pediatrics and movement rates from hospitals. The withdrawal rates of male and female pediatricians registered in 1992, 1994, and 1996 were also analyzed. Results: The number of pediatricians per 10 000 children increased from 1.9 to 7.4 between 1974 and 2004. The percentage of women among pediatricians was significantly higher than that of women among all physicians in 2004 (P < 0.01). The numbers of physicians who withdrew from pediatrics increased from the periods 1985-1994 to 1995-2004. Younger pediatricians tended to leave pediatrics earlier than elder pediatricians. There were no differences in the withdrawal rates of pediatricians between men and women registered in 1992, 1994, and 1996. Conclusions: It is anticipated that the number of pediatricians in Japan will decrease in the near future unless practical strategies are implemented to improve the early withdrawal of younger pediatricians and the current working conditions of female pediatricians.
  • Soichi Koike, Hideo Yasunaga, Shinya Matsumoto, Hiroo Ide, Tomoko Kodama, Tomoaki Imamura
    HEALTH POLICY 92 (2-3) 244 - 249 0168-8510 2009/10 [Refereed][Not invited]
     
    Objectives: To make future estimates of physician distributions in hospitals and clinics to better understand the impact of recent health policy changes in post graduate clinical education, and to discuss possible policy implications. Methods: Analyze National Surveys Data conducted from 1972 to 2004. Multistate Life Table was used to make future estimations of numbers of physicians in hospitals and clinics. Results: A typical Japanese physician's career would start from academic hospitals, and move through non-academic hospitals to clinics. After the introduction of the new post-graduate clinical training system in 2004, more medical school graduates started their careers at non-academic hospitals. Recently, the flow of physicians from academic hospitals to non-academic hospitals has been declining while the flow from academic hospitals to clinics has slightly increased. We also observed a shift of physicians from hospitals to clinics. From the data we estimated that the number of physicians working at clinics will be almost equal to those at non-academic hospitals in 2016, for the first time in 30 years. Conclusions: It is important to discuss the appropriate sharing of roles, responsibilities, and cooperation among medical facilities in line with the observed changes of career paths and physician distributions (C) 2009 Elsevier Ireland Ltd, All rights reserved.
  • Shinya Matsumoto, Manabu Akahane, Yoshiyuki Kanagawa, Soichi Koike, Takesumi Yoshimura, Chikage Mitoma, Satoko Shibata, Hiroshi Uchi, Masutaka Furue, Tomoaki Imamura
    CHEMOSPHERE 77 (5) 658 - 662 0045-6535 2009/10 [Refereed][Not invited]
     
    Yusho (oil disease) is the name given to a food poisoning incident caused by rice bran oil that occurred in west Japan in 1968. The causative agents of Yusho are currently considered to be polychlorinated biphenyls (PCBs) and their by-products, such as dioxin like compounds. The levels of 2,3,4,7,8-penta-cholorodibenzofuran (PeCDF) are measured in the blood of Yusho patients who attend medical check-ups. The objectives of this study were to determine the half-life of PeCDF in these patients. Linear regression analysis was performed with the binary logarithm of PeCDF blood levels in Yusho patients as the dependent variable and the measurement year as the independent variable. The linear coefficient determined in this analysis is the reciprocal of the half-life. The half-life of PeCDF varied among patients. Among patients with PeCDF blood levels of 50 pg g(-1) or higher, there were two groups: one showing a half-life of approximately 7 years and the other showing no reduction in PeCDF levels over time. The results indicate that there is a group of patients whose PeCDF levels are maintained at a high level. Our study suggests that a more complicated model is required to explain PeCDF excretion in humans. (C) 2009 Elsevier Ltd. All rights reserved.
  • Soichi Koike, Shinya Matsumoto, Tomoko Kodama, Hiroo Ide, Hideo Yasunaga, Tomoaki Imamura
    BMC HEALTH SERVICES RESEARCH 9 180  1472-6963 2009/10 [Refereed][Not invited]
     
    Background: Japan has experienced two large changes which affect the supply and distribution of physicians. They are increases in medical school enrollment capacity and in the proportion of female physicians. The purpose of this study is to estimate the future supply of physicians by specialty and to predict the associated impact of increased female physicians, as well as to discuss the possible policy implications. Methods: Based on data from the 2004 and 2006 National Survey of Physicians, Dentists and Pharmacists, we estimated the future supply of physicians by specialty, using multistate life tables. Based on possible scenarios of the future increase in female physicians, we also estimated the supply of physicians by specialty. Results: Even if Japan's current medical school enrollment capacity is maintained in subsequent years, the number of physicians per 1000 population is expected to increase from 2.2 in 2006 to 3.2 in 2036, which is a 46% increase from the current level. The numbers of obstetrician/gynecologists (OB/GYNs) and surgeons are expected to temporarily decline from their current level, whereas the number of OB/GYNs per 1000 births will still increase because of the declining number of births. The number of surgeons per 1000 population, even with the decreasing population, will decline temporarily over the next few years. If the percentage of female physicians continues to increase, the overall number of physicians will not be significantly affected, but in specialties with current very low female physician participation rates, such as surgery, the total number of physicians is expected to decline significantly. Conclusion: At the current medical school enrollment capacity, the number of physicians per population is expected to continue to increase because of the skewed age distribution of physicians and the declining population in Japan. However, with changes in young physicians' choices of medical specialties and as the percentage of female physicians increases, patterns of physician supply will vary between specialties. Specialties less often chosen by young physicians and where males have dominated will face a decline in physician supply. These results highlight the necessity for developing a work environment that attracts female physicians to these types of specialties. This will also lead to improved gender equality in the workforce and more effective use of human resources.
  • ESTIMATION OF PENTA-CHLORODIBENZOFURAN (PECDF) HALF LIFE IN YUSHO PATIENTS
    Manabu Akahane, Shinya Matsumoto, Yoshiyuki Kanagawa, Soichi Koike, Chikage Mitoma, Satoko Shibata, Hiroshi Uchi, Takesumi Yoshimura, Masutaka Furue, Tomoaki Imamura
    DIOXIN 2009Organohalogen Compounds 71 800-804  2009/08 [Not refereed][Not invited]
  • Hiroo Ide, Soichi Koike, Tomoko Kodama, Hideo Yasunaga, Tomoaki Imamura
    HUMAN RESOURCES FOR HEALTH 7 73  1478-4491 2009/08 [Refereed][Not invited]
     
    Background: In Japan, physicians freely choose their specialty and workplace, because to date there is no management system to ensure a balanced distribution of physicians. Physicians in Japan start their careers in hospitals, then become specialists, and then gradually leave hospitals to work in private clinics and take on primary care roles in their specialty fields. The present study aimed to analyse national trends in the distribution and career transitions of physicians among types of facilities and specialties over a 30-year period. Methods: We obtained an electronic file containing physician registration data from the Survey of Physicians, Dentists and Pharmacists. Descriptive statistics and data on movement between facilities (hospitals and clinics) for all physicians from 1974, 1984, 1994 and 2004 were analysed. Descriptive statistics for the groups of physicians who graduated in 1970, 1980 and 1990 were also analysed, and we examined these groups over time to evaluate their changes of occupation and specialty. Results: The number of physicians per 100 000 population was 113 in 1974, and rose to 212 by 2004. The number of physicians working in hospitals increased more than threefold. In Japan, while almost all physicians choose hospital-based positions at the beginning of their career, around 20% of physicians withdrew from hospitals within 10 years, and this trend of leaving hospitals was similar among generations. Physicians who graduated in 1980 and registered in general surgery, cardiovascular surgery or paediatric surgery were 10 times more likely to change their specialty, compared with those who registered in internal medicine. More than half of the physicians who registered in 1970 had changed their specialties within a period of 30 years. Conclusion: The government should focus primarily on changing the physician fee schedule, with careful consideration of the balance between office-based physicians and hospital-based physicians and among specialties. To implement effective policies in managing health care human resources, policy-makers should also pay attention to continuously monitoring physicians' practising status and career motivations; and national consensus is needed regarding the number of physicians required in each type of facility and specialty as well as region.
  • Hiroo Ide, Hideo Yasunaga, Tomoko Kodama, Soichi Koike, Yuji Taketani, Tomoaki Imamura
    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH 35 (4) 761 - 766 1341-8076 2009/08 [Refereed][Not invited]
     
    Aim: A shortage of obstetricians and gynecologists (OB/GYNs) in Japan has been highlighted. We conducted a descriptive and retrospective cohort study using data from the Survey of Physicians in Japan, and analyzed the dynamics of OB/GYNs. Methods: We calculated the total numbers of OB/GYNs, their average age, the percentage of female OB/GYNs, hospital OB/GYNs, and the number of OB/GYNs in rural areas in 1974, 1984, 1994 and 2004. We determined the number of physicians who participated in and left the specialty of obstetrics and gynecology. The withdrawal rates of OB/GYN,; who graduated in 1972, 1982 and 1992 were retrospectively followed using survival analysis. Results: The overall number of physicians has increased, while the number of OB/GYNs has remained almost unchanged over the past 30 years. The percentage of female OB/GYNs has increased. Fewer new graduates chose obstetrics and gynecology, the withdrawal rate of current OB/GYNs decreased, and their average age (50.8 years) increased. The trend in withdrawal rates did not differ significantly among the generations. Conclusions: The gravest problem in the OB/GYNs workforce is the continued decline in newly graduated OB/GYNs. Improvements in working conditions and job satisfaction are considered vital.
  • Yoshiyuki Kanagawa, Shinya Matsumoto, Soichi Koike, Tomoaki Imamura
    PEDIATRIC ALLERGY AND IMMUNOLOGY 20 (4) 347 - 352 0905-6157 2009/06 [Refereed][Not invited]
     
    Food allergy patients are known to present with allergic reactions to multiple allergens, but extrapolating these associations is difficult. Data mining, a procedure that analyzes characteristic combinations among large amounts of information, is often used to analyze and predict consumer purchasing behaviour. We applied this technique to the extrapolation of food allergen associations in allergy patients. We sent 1510 families our 'Questionnaire survey for the prevention of food allergies'. Responses noting 6549 allergens came from 878 families with 1383 patients, including 402 with anaphylaxis. Some results of the survey have already been published and here we presented the results of our association analysis of combinations of food allergens. Egg, milk, wheat, peanuts, and buckwheat are the most common food allergens. The most common simultaneous combinations of these allergens were 'egg-milk', 'egg-wheat', and 'milk-wheat'. The occurrence probability of a combination (i.e. one person suffering from a certain allergen also suffers from another) is called 'confidence'. Confidence was higher for 'chicken-egg', 'abalone-salmon eggs', and 'matsutake mushroom-milk'. As well, the combinations of 'crab-shrimp', 'squid-shrimp', and 'squid-crab' also indicated higher values in a statistical examination of the occurrence probabilities of these allergen combinations (Z-score). From the results of the association analysis, we speculated that some food allergens, such as abalone, orange, salmon, chicken, pork, matsutake mushroom, peach and apple did not independently induce food allergies. We also found that combinations, such as 'crab-shrimp', 'squid-shrimp', 'squid-crab', 'chicken-beef', and 'salmon-mackerel' had strong associations.
  • Tomoaki Imamura, Shinya Matsumoto, Manabu Akahane, Yoshiyuki Kanagawa, Soichi Koike, Bunichi Tajima, Shiro Matsuya, Hiroshi Uchi, Satoko Shibata, Masutaka Furue
    BMC Research Notes 2 27  1756-0500 2009 [Refereed][Not invited]
     
    Background. Yusho an intoxication caused by oral dioxins and polychlorinated biphenyls occurred in 1968. Patients suffered from various systemic symptoms, including general fatigue, nausea, muscular and articular pain, acneform eruptions, black comedones, cutaneous and oral pigmentation, and increased eye discharge. The major causative factor was the contamination of rice oil with 2,3,4,7,8-penta-chlorodibenzofuran (PeCDF). Recent technical advances have allowed us to measure blood levels of PeCDF. However, there is little information on which symptoms and laboratory data are directly associated with PeCDF levels. Methods. Yusho patients underwent annual medical check-ups from 2001 to 2003. Blood PeCDF levels were correlated with the presence or absence of symptoms in medical, hematological, dermatological, dental and ophthalmological examinations. This study analyzed all combinations by using the association analysis. This is the most suitable method to evaluate all combinations of the data comprehensively. This method was used to determine the rate of patients with high PeCDF level in the population with each symptom, and to extract combinations of three symptoms which were strongly associated with high PeCDF level. Results and Conclusion. The rate of the patients with high PeCDF level was high in populations with high uric acid, black comedones (face), second highest quartile of age, or high urea nitrogen. The combination of three symptoms associated with the highest rate of patients with high PeCDF level was "high uric acid, female sexuality, and history of acneform eruptions", followed by "history of Yusho in and after 1968, high cholesterol level, and subjective symptoms." This analysis newly suggested that PeCDF concentration may be associated with history of dermatological symptoms, high uric acid, and elevated erythrocyte sedimentation rate. © 2009 Imamura et al.
  • 小池 創一, 勝村 裕一, 児玉 知子, 井出 博生, 康永 秀生, 松本 伸哉, 今村 知明
    厚生の指標 (一財)厚生労働統計協会 55 (11) 22 - 28 0452-6104 2008/10 
    目的 医師需給についての考察をさらに深めるため,医師・歯科医師・薬剤師調査のデータを用いて診療所勤務医師(いわゆる開業医)の現状を明らかにするとともに,多相生命表の原理を用いて,医師の診療科間の移動の側面を考慮した医師の将来推計を行うことを目的とした。方法 1972年から2004年調査までの医師・歯科医師・薬剤師調査データを用いて,各年度の調査について横断的に解析を行うとともに,医籍登録番号を用いて縦断的にデータを結合し,医師の勤務状況の変化について解析を行った。さらに,2002年と2004年調査から多相生命表の原理を用いて診療科別の医師数の将来推計を行った。結果 診療所勤務医の年齢構成に経年的に変化が生じていることが明らかになるとともに,診療所勤務医を引退する年齢が上昇してきている可能性が示唆された。2002年から2004年の移動率,および2004年の新規登録医師数が今後も変わらないと仮定した場合の医師数は,2010年で内科10.7万人,小児科1.6万人,精神科1.4万人,外科5.3万人,産婦人科1.2万人,その他8.9万人で合計29.0万,2020年で内科11.8万人,小児科1.8万人,精神科1.6万人,外科5.3万人,産婦人科1.2万人,その他10.2万人で,合計32.0万人と推計された。結論 本研究で用いた多相生命表の原理を用いれば,診療科別の将来推計に加えて,病院,診療所といった勤務の種別,都市部と地方といった医師の地域分布についても推計が可能であることが示唆され,医師需給の議論を深化させる上で有益な情報を提供しうることが示唆された。新臨床研修を終えた者が最初に届け出を行う2006年医師・歯科医師・薬剤師調査のデータを用いることが可能となり次第,今回の結果と比較することで,新臨床研修制度が医師の診療科の選択・診療科間の移動に与えた影響を評価した形での将来推計を行う等,さらなる研究が推進されることが期待される。(著者抄録)
  • Yoshiyuki Kanagawa, Shinya Matsumoto, Soichi Koike, Bunichi Tajima, Noriko Fukiwake, Satoko Shibata, Hiroshi Uchi, Masutaka Furue, Tomoaki Imamura
    ENVIRONMENTAL HEALTH 7 47  1476-069X 2008/10 [Refereed][Not invited]
     
    Background: The Yusho poisoning incident, which was caused by rice bran oil contaminated with polychlorinated biphenyls (PCBs), polychlorinated quarterphenyls (PCQs) and polychlorinated dibenzofurans (PCDFs) generated by heat denaturation of PCB, occurred in 1968 in western Japan. Annual physical, dermatological, dental, ophthalmological and laboratory examinations were conducted for Yusho patients after the incident. From 2001, blood levels of individual PCDF congeners were also measured. The blood levels of 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF), PCBs and PCQs in Yusho patients were found to be significantly higher than those of the general population. We investigated the relationships between blood concentrations of 2,3,4,7,8PeCDF, PCBs and PCQs in Yusho patients and the items measured in the annual medical examination. Methods: Medical and laboratory examination data from 501 Yusho patients enrolled in the study from 2001 to 2004 were analyzed. The relationships between blood 2,3,4,7,8-PeCDF, PCB and PCQ concentrations and medical/laboratory examination data were investigated using principal components and logistic regression analyses. Results: Serum Concentrations of 2,3,4,7,8-PeCDF, PCBs and PCQs in blood tended to correlate with either acneform eruptions, black comedones, cutaneous and mucosal pigmentation, and hypersecretion of meibomian glands as well as general fatigue, headaches, cough/sputum, abdominal pain, arthralgia, increased blood sugar, increased serum.-GTP and decreased total bilirubin. The majority of these signs and symptoms are included in the diagnostic criteria for Yusho. Conclusion: After Yusho patients had suffered chronic exposure to these chlorinated compounds for more than 35 years, the serum concentration of 2,3,4,7,8-PeCDF in blood was significantly related to arthralgia and decreased albumin/globulin (A/G) ratio; the serum concentration of PCBs was significantly related to ophthalmologic symptoms; and the serum concentration of PCQ to increased total cholesterol. These findings suggest that the co-contaminants may affect other functions than those originally associated with Yusho.
  • KOIKE Soichi
    慶應醫學 慶應医学会 81 (4) 271 - 286 0368-5179 2004/11 [Not refereed][Not invited]
     
    The purpose of this study was to compare the long-term care services in municipalities before and after the introduction of Long-term Care Insurance for the elderly (LTCI) in April 2000, Questionnaires were sent to all municipalides in Japan in November 1999 (before the introduction of (LTCI) and in 2001(after the introduction of LTCI). The questions included the level of care needed for the elderly, the type of service (home or institution-based), and other factors related to the implementation of LTCI. Two hundred and sixty-five municipalities responded to both questionnaires were analyzed in this study. The proportion of elderly who needed care, the pmportion of elderly at care need level 5, and the average care-need level among certified increased and became less variable afterthe introduction of LTCl, In addition, there was a higher correlation between the proportion of elderly who needed care and the number of beds for long-term care per elderly population after the introduction of LTCI. The standardization of eligibility criteria and the changes in the financing system for care for the elderly served as background of these changes. These findings demonstrate that the introduction of LTCI had a significant impact on care for the elderly in municipalities in Japan.

Books etc

  • 地域医療学入門
    日本医学教育学会地域医療教育委員会, 全国地域医療教育協議会, 合同編集委員会, 監修 (Contributor第2章 1. 行政の役割と関連法規)
    診断と治療社 2019/07 9784787823847 184 38-41
  • Japan Health System Review.Health systems in transition. Vol-8, Number-1
    Sakamoto H, Rahman M, Nomura S, Okamoto E, Koike S, Yasunaga H, Kawakami N, Hashimoto H, Abe S, Palmer M, Ghaznavi C (Joint work)
    World Health Organization, Regional Office for South- East Asia, 2018/02
  • 新体系 看護学全書 健康支援と社会保障制度 公衆衛生学
    佐々木明子, 井原一成 (Contributor第11章 国際保健)
    メヂカルフレンド社 2016/12 9784839233075 329-40
  • 医療情報の利活用と個人情報保護
    東京大学大学院医学系研究科医療経営政策学講座 (Contributor第9章 医療情報の利活用と公的統計調査の調査票情報))
    EDITEX 2015/10 4903320391 151 113-121
  • 敗血症と臓器障害
    葛西健, 宇都宮啓, 小池創一, 渡辺正俊, 中野滋文, 藤井紀夫, 鈴木泰, 遠藤重厚 (Contributor敗血症の疫学)
    岩手医科大学医学部救急医学講座 2010/07 9784990530921 32-41
  • 油症研究Ⅱ 治療と研究の最前線
    松本伸哉, 赤羽学, 神奈川芳行, 小池創一, 今村知明 (Contributor第7章 油症患者におけるPeCDFの残留濃度と半減期)
    九州大学出版会 2010/02 4798500070 72-78

MISC

  • 医師確保計画における医師少数スポットの実態:無医地区との関係の検討
    寺裏寛之, 小谷和彦, 野原康弘, 小池創一  厚生の指標  68-  (8)  1  -8  2021/08  [Refereed][Not invited]
  • 地域医療の現状と産業医制度への示唆
    小池創一  Occupational Health Journal  43-  (4)  16  -18  2020/07  [Not refereed][Invited]
  • Atarashi H, Hirose M, Ide H, Koike S  The Japanese Journal of Medical Instrumentation  90-  (3)  245  -255  2020/06  [Refereed][Not invited]
  • 小池 創一, 松本 正俊, 鈴木 達也, 寺裏 寛之, 前田 隆浩, 井口 清太郎, 春山 早苗, 小谷 和彦  厚生の指標 = Journal of health and welfare statistics  67-  (5)  20  -26  2020/05  [Refereed][Not invited]
  • 地域医療政策の動向-地域医療構想、医師偏在対策、医師の働き方改革を中心に
    小池 創一  医学のあゆみ  270-  (8)  657  -663  2019/08  [Not refereed][Invited]
  • 小池 創一, 古井 祐司, 磯 博康, 山縣 然太朗, 津下 一代, 三浦 克之, 宮本 恵宏, 立石 清一郎, 岡村 智教  厚生の指標  66-  (7)  1  -7  2019/07  [Refereed][Not invited]
     
    目的 特定健康診査・特定保健指導も制度開始から10年が経過し、将来的な健診・保健指導制度の在り方、特に生涯を通じた健康づくりに対して、保険者が制度を超えてどのように対応していくかについて検討することは重要になっている。このような状況を踏まえ、本研究では、定年退職等により新たに市町村国民健康保険(国保)の被保険者になった者の特徴、保険者による健康状況の把握や制度周知に関する取り組みの状況、国民健康保険団体連合会(国保連)が行う保険者支援の実態等について明らかにするとともに、今後の課題について検討することとした。方法 市町村国保の保険者と国保連に、郵送による自記式質問紙調査を行った。質問項目は、保険者調査では、定年等による新規加入者の健康状態や受療行動の課題、前保険者に求めたい取り組み、国保へ異動してきた者への取り組み内容を、国保連向け調査では、国保へ異動してきた者の健康状態や受療行動、個々の保険者支援、保険者間異動時の情報のやり取り等の有無と内容について、選択肢を提示するとともに自由記載欄を設けた。結果 1,225保険者(回収率71.4%)、38国保連(回収率80.9%)から有効回答を得た。国保へ異動してきた者と国保に継続して加入している者の健康状態や受療行動に差があるかとの質問について、保険者調査では3/4、国保連調査でも4割強が分からないと回答していたが、差があると感じている場合には、国保移行者の方が特定健康診査の受診率や特定保健指導の完遂率などが高いと感じる保険者と、低いと感じる保険者はほぼ拮抗していた。保険者が、前保険者に期待していることには、制度変更に関する情報提供が約2/3と最多で、前保険者の健診結果等のデータ提供や、「健康問題への意識づけ」についても約半数の保険者が選択をしていた。国保連に関して、保険者間異動時の情報のやり取りや健康管理の引き継ぎに関しては、9割近い国保連から議論を行っているとの回答を得た。結論 保険者、国保連に対するアンケート調査の結果、保険者間異動前後の保健指導や受療動向や、各種データの活用についてはいまだ課題があることが明らかになった。また、保険者間異動後も継続的に取り組める生活習慣病の重症化予防に向けた取り組みの重要性も示唆された。(著者抄録)
  • 麻生 将太郎, 康永 秀生, 小池 創一  厚生の指標  66-  (6)  31  -36  2019/06  [Refereed][Not invited]
     
    目的 これまで日本の専門医数の将来推計を行った研究はない。専門医の適正配置のために各診療科の専門医数の将来推計を行った。方法 2010年から2014年の医師・歯科医師・薬剤師調査の個票データに基づいて、Markovモデルを用いて、基本領域(精神科、臨床検査科を除く)の専門医数の将来推計を2038年まで行った。新人医師数が7,000人/年増加すると仮定し、男女比を7:3とした。定年退職する医師の男女比は実測値に基づき、年に応じて変化させた。専門医取得、維持、喪失のステータスの移行確率は、推計期間中一定とした。労働力を算出する際の重みづけは、60歳以上、あるいは女性は0.8、それ以外は1とした。結果 256,885人の医師の背景は、男性77.9%、平均年齢40.9歳、診療所勤務28.9%、市中病院勤務50.8%、大学病院勤務20.3%であった。ほぼすべての診療科で専門医数は増加し、2014年と比較して、形成外科(1.66倍)、救急科(1.58倍)で比較的大きく増加する。男性の専門医数はリハビリテーション科(0.68倍)、外科(0.85倍)で減少する。女性の専門医数は全診療科で増加し、特に形成外科(3.27倍)、泌尿器科(3.04倍)で比較的大きく増加する。2016年を1としたときの2038年における「女性の専門医数の増加比」はすべての診療科で1.5以上であり、特に泌尿器科(2.73)、リハビリテーション科(2.72)、外科(2.48)が大きい値となった。「労働力の増加率」もすべての診療科で1倍以上であり、特に形成外科(1.91倍)、救急科(1.78倍)で大きい値となった。結論 専門医数は全診療科で増加するものの、診療科によって大きなばらつきがある。女性の専門医数が増加するものの、専門医の労働力の減少にはつながらないことが示唆された。(著者抄録)
  • Soichi Koike  The Japanese Journal of Clinical Dialysis  34-  (12)  9  -17  2018/11  [Not refereed][Invited]
  • Atarashi H, Hirose M, Ide H, Koike S  Clinical Engineering  29-  (11)  947  -958  2018/11  [Not refereed][Invited]
  • Inter / Multi-disciplinary cooperation in community Medicine
    Kotani K, Koike S, Matsumura M  Journal of Japanese Society of Internal MedicineI  107-  (11)  2294  -2300  2018/11  [Not refereed][Invited]
  • 石丸美穂, 大野幸子, 松居宏樹, 康永秀生, 小池創一  厚生の指標  64-  (2)  30  -37  2017/02  [Refereed][Not invited]
  • Shunsuke Doi, Hiroo Ide, Shinji Ogawa, Katsuhiko Takabayashi, Shinsuke Fujita, Soichi Koike  KNOWLEDGE-BASED AND INTELLIGENT INFORMATION & ENGINEERING SYSTEMS 19TH ANNUAL CONFERENCE, KES-2015  60-  1631  -1639  2015  [Not refereed][Not invited]
     
    In this study, we developed a probabilistic model to analyze patient accessibility to hospitals by using a geographic information system (GIS). In the consideration of patient accessibility, we do not have correct patient addresses because of the laws related to protection of a patient's personal information. Thus, we use a representational place in the city or the ZIP code of the area. However, this may lead to a decline in the accuracy of the analysis. In this study, we used a 500-m mesh map and obtained the population gender and age group data from the national census data, in order to estimate the patient accessibility to medical facilities in small areas. We calculated the probability that a patient lives in each mesh on the basis of the population gender and five-year age group data. We selected the appropriate mesh on the basis of this probability and investigated the time distance from the estimated mesh to each hospital by using a GIS. As a result, we calculated the time distance and its distribution by using the proposed method from limited available information. Further, we found that in the target cities, the average time distance to hospital calculated using the proposed method was longer than that calculated by using a previous method; the percentage of patients who took more time than the city average to reach a hospital by using the proposed method. This method is very useful when planning the geographical resource allocation of medical services. (C) 2015 Published by Elsevier B.V.
  • Toshio Ogawa, Seizan Tanabe, Soichi Koike, Tomoaki Imamura  CIRCULATION  126-  (21)  2012/11  [Not refereed][Not invited]
  • Soichi Koike, Seizan Tanabe, Toshio Ogawa, Manabu Akahane, Hideo Yasunaga, Hiromasa Horiguchi, Shinya Matsumoto, Tomoaki Imamura  PREHOSPITAL EMERGENCY CARE  15-  (4)  579  -580  2011/10  [Not refereed][Invited]
  • 児玉 知子, 小池 創一, 松本 伸哉  厚生の指標  58-  (8)  1  -7  2011/08  [Not refereed][Not invited]
  • 神奈川 芳行, 小池 創一, 武内 澄子, 今村 知明  食品衛生研究  60-  (6)  15  -23  2010/06  [Refereed][Not invited]
  • 赤羽 学, 松本 伸哉, 神奈川 芳行, 梶原 淳睦, 戸髙 尊, 平川 博仙, 小池 創一, 古江 増隆, 今村 知明  Fukuoka acta medica  100-  (5)  172  -178  2009/05  [Not refereed][Not invited]
     
    The half-life of 2,3,4,7,8-penta-chlorodibenzofuran (PeCDF) in the Yusho patients has been reported to be approximately seven years. In the present study, we estimated the half-life of PeCDF using data from the medical check-ups of more than 300 Yusho patients. We performed linear regression analysis with a binary logarithm of PeCDF blood level in Yusho patients as the dependent variable, and the measurement year as the independent variable. Our results showed that there were many patients who had shown no reduction of their blood PeCDF level for several years. This result contradicts the previously reported half-life period. Therefore, we believe that a more complicated excretion model needs to be established to explain the discrepancy we found. We hypothesized that there might be two mechanisms of PeCDF assimilation in human digestive tract. In the present study, we also used our hypothesis to simulate PeCDF excretion in Yusho patients.
  • 神奈川 芳行, 松本 伸哉, 赤羽 学, 小池 創一, 吉村 健清, 内 博史, 古江 増隆, 今村 知明  Fukuoka acta medica  100-  (5)  166  -171  2009/05  [Not refereed][Not invited]
     
    [Background] Since 1968, when the Yusho poisoning incident occurred, annual physical, dermatological, dental, and ophthalmological and laboratory examinations, collectively called Yusho health checks, have been conducted for Yusho patients. The Yusho incident was a health hazard caused by intake of rice-bran oil contaminated with PCB and PeCDF ; therefore, since 2001 the levels of dioxins such as PeCDF in the blood have been measured in applicants. Here, we investigated correlations among findings from various medical examinations and those between those findings and PeCDF, PCB, and PCQ. [Patients and Methods] Subjects were Yusho patients who underwent Yusho annual health checks and had their levels of PeCDF measured between 2001 and 2004. The results of 4 years of health checks of those who underwent the health checks for 2 years or longer were aggregated to extract representative inspection items by principal component analysis. We also investigated the presence or absence of correlations among these items and PeCDF, PCB, and PCQ levels in blood. [Results] Using 49 variables extracted by principal component analysis as objective variables, we determined that there were correlations between the following combinations : arthralgia, A/G ratio and PeCDF level, ophthalmological symptoms such as excessive eye discharge and PCB level, and total cholesterol, inferior gingival pigmentation and PCQ level.
  • KOIKE Soichi  Japanese journal of public health  49-  (12)  1268  -1277  2002/12  [Refereed][Not invited]
  • 小池 創一  保健婦雑誌  58-  (3)  190  -196  2002/03  [Not refereed][Not invited]
  • Shinoda-Tagawa T, Koike S  Harvard Health Policy Review  3-  (1)  27  -35  2002  [Refereed][Not invited]
  • 小池 創一  地域ケアリング  1-  (7)  78  -82  1999/09  [Not refereed][Not invited]
  • 小池 創一  社会保険  50-  (7)  4  -7  1999/07  [Not refereed][Not invited]
  • 橋本修二, 藤田 利治, 小池 創一  厚生の指標  42-  (2)  3  -8  1995/02  [Not refereed][Not invited]
  • 中村 好一, 橋本 修二, 小池 創一  厚生の指標  41-  (10)  26  -33  1994/09  [Not refereed][Not invited]
  • 小池 創一, 今村 知明, 小野寺 すゑ 他  厚生の指標  41-  (8)  p9  -15  1994/08  [Not refereed][Not invited]
  • 小池 創一, 今村 知明, 山根 昌子  厚生の指標  41-  (7)  p9  -16  1994/07  [Not refereed][Not invited]
  • 橋本 修二, 中村 好一, 小池 創一  厚生の指標  41-  (6)  3  -12  1994/06  [Not refereed][Not invited]
  • 中村 好一, 橋本 修二, 小池 創一  厚生の指標  41-  (5)  3  -9  1994/05  [Not refereed][Not invited]


Copyright © MEDIA FUSION Co.,Ltd. All rights reserved.