山名 隼人

BACKGROUND AND HYPOTHESIS: We aimed to evaluate the diagnostic validity of the International Classification of Diseases, 10th Revision (ICD-10) codes for hyponatremia and hypernatremia, using a database containing laboratory data. We also aimed to clarify whether corrections for blood glucose, triglyceride, and total protein may affect the prevalence and the diagnostic validity. METHODS: We retrospectively identified admissions with laboratory values using a Japanese hospital-based database. We calculated the sensitivity, specificity, and positive/negative predictive values of recorded ICD-10-based diagnoses of hyponatremia (E87.1) and hypernatremia (E87.2), using serum sodium measurements during hospitalization (<135 and >145 mmol/l, respectively) as the reference standard. We also performed analyses with corrections of sodium concentrations for blood glucose, triglyceride, and total protein. RESULTS: We identified 1 813 356 hospitalizations, including 419 470 hyponatremic and 132 563 hypernatremic cases based on laboratory measurements, and 18 378 hyponatremic and 2950 hypernatremic cases based on ICD-10 codes. The sensitivity, specificity, positive predictive value, and negative predictive value of the ICD-10 codes were 4.1%, 99.9%, 92.5%, and 77.6%, respectively, for hyponatremia and 2.2%, >99.9%, 96.5%, and 92.8%, respectively, for hypernatremia. Corrections for blood glucose, triglyceride, and total protein did not largely alter diagnostic values, although prevalence changed especially after corrections for blood glucose and total protein. CONCLUSIONS: The ICD-10 diagnostic codes showed low sensitivity, high specificity, and high positive predictive value for identifying hyponatremia and hypernatremia. Corrections for glucose or total protein did not affect diagnostic values but would be necessary for accurate prevalence calculation.

OBJECTIVES: Polypharmacy is an important healthcare issue, especially in elderly patients with dementia. As an incentive to reduce polypharmacy, a health insurance reimbursement scheme was introduced in 2016 for medication review and the reduction of medications for inpatients in Japan. However, the effects of these incentive schemes were not evaluated. METHODS: We identified 1,465,881 inpatients aged ≥65 years with dementia. An interrupted time-series analysis was conducted by fitting a Prais-Winsten linear regression model. The outcome measure was the number of classes of medications prescribed during discharge. RESULTS: No significant changes were observed in the average number of medication classes at discharge immediately after the introduction of the scheme (coefficient: -0.022, 95% confidence interval [CI]: -0.17 to 0.13). The slope change, representing the effect of the intervention over time, was also not significant (coefficient: -0.00053, 95% confidence interval: -0.0012 to 0.00018). CONCLUSIONS: The incentive scheme was not associated with a reduction in the number of medication classes at discharge among older inpatients with dementia.

BACKGROUND: Vertebral compression fractures (VCFs) in older adults cause considerable health and socioeconomic burdens due to worsening ability to perform activities of daily living. The long-term effects of VCFs on patient outcomes, particularly prolonged analgesic use and functional decline, remain unknown. The aims of this study were to examine long-term clinical outcomes and to determine the risk factors for persistent pain and functional disability after VCFs. METHODS: This retrospective cohort study evaluated mortality, duration of analgesic use, and changes in care requirements in older adults with VCFs using claims data from a suburban prefecture in the Greater Tokyo Area. Patients were included if they were ≥65 years of age and had been diagnosed with a VCF between June 2014 and February 2019, as determined on the basis of International Classification of Diseases, Tenth Revision (ICD-10) codes; we also used claims data that could determine whether the patients underwent imaging examinations. Patients who discontinued outpatient visits within 1 month after the VCF diagnosis were excluded. RESULTS: We included 18,392 patients with VCFs and a mean age of 80 years. Seventy-six percent of patients were women, and the median follow-up period was 670 days. At the index VCF diagnosis, 3,631 patients (19.7%) were care-dependent. Overall, 968 patients (5.3%) died within 1 year. Among the 8,375 patients who received analgesics, 22% required analgesics for >4 months. Factors associated with prolonged analgesic use for >1 year were female sex (odds ratio [OR], 1.39 [95% confidence interval (CI), 1.16 to 1.65]) and VCFs in the thoracolumbar region (OR, 1.95 [95% CI, 1.50 to 2.55]) or lumbar region (OR, 1.59 [95% CI, 1.23 to 2.04]) (the reference was the thoracic region). The care needs of 1,510 patients (8.2%) increased within 1 year. Patients with a preexisting care dependency had a 10 times higher risk of increased care need (30.2% [1,060 of 3,509]) than those who had been independent at the time of the index diagnosis (3.0% [450 of 14,761]) (p < 0.001). CONCLUSIONS: Individuals with preexisting care dependency were more likely to experience functional decline following VCFs than those who were independent, which underscores the need for intensive and appropriate allocation of health-care resources to care-dependent patients. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

AIM: The importance of comprehensive geriatric assessment (CGA) is increasing in aging societies worldwide. However, there are few comprehensive studies on CGA, resulting in a limited understanding of its implementation rate, temporal changes and factors associated with its implementation. We aimed to investigate the implementation status of CGA and its regional variance in Japan. METHODS: Using the Diagnosis Procedure Combination database, we investigated CGA trends, and identified the patient, hospital and regional factors associated with its implementation. We identified patients aged ≥65 years who were admitted for the first time between 2016 and 2020 with a diagnosis of stroke, heart failure, pneumonia, bone fracture or colorectal cancer. We examined the CGA implementation rate according to patient and hospital characteristics. We also investigated temporal changes and tendencies to carry out CGA in different prefectures. RESULTS: A total of 1 974 817 patients were analyzed, of whom 570 696 (28.9%) underwent CGA. The implementation trend increased steadily from 25.3% in fiscal year 2016 to 33.4% in fiscal year 2019. The implementation rate also increased with patient age (30.3% in patients aged ≥95 years). Regional variations in its implementation status were observed, with a higher tendency to be implemented in areas near major metropolitan regions. A trend toward carrying out CGA for colorectal cancer, but not for other diseases, has been observed in eastern Japan. CONCLUSION: Although CGA is increasingly carried out, considerable regional differences remain in its implementation status. Initiatives to reduce variations are necessary. Geriatr Gerontol Int 2024; ••: ••-••.

BACKGROUND: Most evidence of the waning of vaccine effectiveness is limited to a relatively short period after vaccination. METHODS: Data obtained from a linked database of healthcare administrative claims and vaccination records maintained by the municipality of a city in the Kanto region of Japan were used in this study. The study period extended from April 1, 2020, to December 31, 2022. The duration of the effectiveness of the COVID-19 vaccine was analyzed using a time-dependent piecewise Cox proportional hazard model using the age, sex and history of cancer, diabetes, chronic obstructive pulmonary disease, asthma, chronic kidney disease, and cardiovascular disease as covariates. RESULTS: Among the 174,757 eligible individuals, 14,416 (8.3%) were diagnosed with COVID-19 and 936 (0.54%) were hospitalized for COVID-19. Multivariate analysis based on the time-dependent Cox regression model with reference of non-vaccine group revealed a lower incidence of COVID-19 in the one-dose group (hazard ratio, 0.76 [95% confidence interval, 0.63-0.91]), two-dose (0.89 [0.85-0.93]), three-dose (0.80 [0.76-0.85]), four-dose (0.93 [0.88-1.00]), and five-dose (0.72 [0.62-0.84]) groups. A lower incidence of COVID-19-related hospitalization was observed in the one-dose group (0.42 [0.21-0.81]), two-dose (0.44 [0.35-0.56]), three-dose (0.38 [0.30-0.47]), four-dose (0.20 [0.14-0.28]), and five-dose (0.11 [0.014-0.86]) groups. Multivariable analyses based on the time-dependent piecewise Cox proportional hazard model with reference of non-vaccine group revealed significant preventive effects of the vaccine for 4 months for the incidence of COVID-19 and ≥ 6 months for hospitalization. CONCLUSIONS: Vaccine effectiveness showed gradual attenuation with time after vaccination; however, protective effects against the incidence of COVID-19 and hospitalization were maintained for 4 months and ≥ 6 months, respectively. These results may aid in formulating routine vaccination plans after the COVID-19 pandemic.

BACKGROUND: Patients who receive invasive mechanical ventilation (IMV) in the intensive care unit (ICU) have exhibited lower in-hospital mortality rates than those who are treated outside. However, the patient-, hospital-, and regional factors influencing the ICU admission of patients with IMV have not been quantitatively examined. METHODS: This retrospective cohort study used data from the nationwide Japanese inpatient administrative database and medical facility statistics. We included patients aged ≥ 15 years who underwent IMV between April 2018 and March 2019. The primary outcome was ICU admission on the day of IMV initiation. Multilevel logistic regression analyses incorporating patient-, hospital-, or regional-level variables were used to assess cluster effects by calculating the intraclass correlation coefficient (ICC), median odds ratio (MOR), and proportional change in variance (PCV). RESULTS: Among 83,346 eligible patients from 546 hospitals across 140 areas, 40.4% were treated in ICUs on their IMV start day. ICU admission rates varied widely between hospitals (median 0.7%, interquartile range 0-44.5%) and regions (median 28.7%, interquartile range 0.9-46.2%). Multilevel analyses revealed significant effects of hospital cluster (ICC 82.2% and MOR 41.4) and regional cluster (ICC 67.3% and MOR 12.0). Including patient-level variables did not change these ICCs and MORs, with a PCV of 2.3% and - 1.0%, respectively. Further adjustment for hospital- and regional-level variables decreased the ICC and MOR, with a PCV of 95.2% and 85.6%, respectively. Among the hospital- and regional-level variables, hospitals with ICU beds and regions with ICU beds had a statistically significant and strong association with ICU admission. CONCLUSIONS: Our results revealed that primarily hospital and regional factors, rather than patient-related ones, opposed ICU admissions for patients with IMV. This has important implications for healthcare policymakers planning interventions for optimal ICU resource allocation.

OBJECTIVE: The study aimed to investigate treatment options for older women with pelvic organ prolapse (POP) and postoperative outcomes based on their long-term care (LTC) status. METHODS: We used the medical and LTC insurance claims databases of Tochigi Prefecture in Japan, covering 2014 to 2019. We included women 65 years and older with POP and evaluated their care status and treatment, excluding women with an observation period <6 months. Among women with a postsurgical interval ≥6 months, we compared care level changes and deaths within 6 months and complications within 1 month postoperatively between those with and without LTC using Fisher exact test. RESULTS: We identified 3406 eligible women. Of the 447 women with LTC and 2959 women without LTC, 16 (3.6%) and 415 (14.0%), respectively, underwent surgery. Among 393 women with a postsurgical interval ≥6 months, 19 (4.8%) required LTC at surgery. Two of the 19 women with LTC (10.5%) and eight of 374 women without LTC (2.1%) experienced worsening care-needs level. No deaths were recorded. Urinary tract infection (UTI) was significantly more frequent in women with LTC than in women without LTC (36.8% vs 8.6%). Other complications were rare in both groups. CONCLUSION: The proportion of patients who underwent surgery for POP was lower in women with LTC than in women without LTC. Postoperative UTI was common and 11% had a worsening care-needs level postoperatively, whereas other complications were infrequent. Further detailed studies would contribute to providing optimal treatment to enhance patients' quality of life.

PURPOSE: Perinatal mood disorders affect both parents, impacting their children negatively. Little is known on the association between parental perinatal mood disorders and pediatric outcomes in Japan considering relevant covariates. Our objective was to investigate the association between paternal and maternal perinatal mood disorders and adverse physical and psychological child outcomes by the age of 36 months, adjusting for covariates such as the child's sex, age of parent at child's birth, perinatal mood disorders of the other parent, and perinatal antidepressant use. METHODS: We identified parents in the JMDC Claims Database in Japan from 2012 to 2020. Perinatal mood disorders were defined using International Classification of Diseases, 10th codes for mood disorders during the perinatal period combined with psychiatric treatment codes. We evaluated the association between parental perinatal mood disorders and pediatric adverse outcomes by the age of 36 months using Cox proportional hazard models adjusted for the covariates. RESULTS: Of the 116,423 father-mother-child triads, 2.8% of fathers and 2.3% of mothers had perinatal mood disorders. Paternal perinatal mood disorders were not significantly associated with adverse child outcomes. After adjusting for paternal perinatal mood disorders and antidepressant use, maternal perinatal mood disorders were associated with delayed motor development, language development disorders, autism spectrum disorders, and behavioral and emotional disorders (adjusted hazard ratio [95% confidence interval]: 1.65 [1.01-2.69], 2.26 [1.36-3.75], 4.16 [2.64-6.55], and 6.12 [1.35-27.81], respectively). CONCLUSIONS: Paternal perinatal mood disorders were not associated with adverse child outcomes in this population. Maternal perinatal mood disorders were associated with multiple child outcomes.

AIM: This study aimed to elucidate the impact of periodontal therapy on glycaemic control in individuals with type 2 diabetes and various baseline blood glucose levels using a large-scale claims database from Japan. MATERIALS AND METHODS: Using the JMDC Claims Database, we identified individuals with type 2 diabetes who underwent health check-ups in the fiscal years 2018 or 2019 and were followed up until the next year's health check-up. We conducted a weighted cohort analysis using stabilized inverse probability weights for treatment and censoring to estimate the effect of periodontal therapy on changes in haemoglobin A1c levels within a year. Analysis was done for different baseline haemoglobin A1c categories: 6.5%-6.9%, 7.0%-7.9% and ≥8.0%. RESULTS: Of the 4279 insured persons included in the study, 957 received periodontal therapy. Overall, there was a tendency towards improved glycaemic control among those who received periodontal therapy. Participants with baseline haemoglobin A1c levels of 7.0%-7.9% who received periodontal therapy exhibited significantly better glycaemic control compared with those without dental visits (difference; -0.094 [95% confidence interval: -0.181 to -0.007]). CONCLUSIONS: Periodontal therapy may improve glycaemic control in individuals with diabetes, especially in those with haemoglobin A1c levels ≥7.0%.

BACKGROUND: Delayed vaccination is a well-studied and critical public health issue. However, limited studies have explored whether familial factors influence vaccination delay. This study aimed to determine whether family structure and comorbidities affect the refusal or delayed receipt of measles-rubella and varicella vaccines. METHODS: We gathered data on all children from birth to 13 months of age between 2006 and 2020 using vaccination records linked with the administrative healthcare claims data from a Japanese city. Multivariable logistic regression analyses were conducted to examine the association of refusal or delay in receiving the first-dose measles-rubella and varicella vaccines with the following factors: the child's sex; presence of parents, siblings, and grandparents; parental and grandparental comorbidities; chronic pediatric comorbidities in the child and siblings; and year of vaccination. RESULTS: We identified a total of 14,241 eligible children. Refusal or delayed receipt of the first-dose measles-rubella vaccine was associated with an adjusted odds ratio of 2.46 (95% confidence interval, 1.86-3.24) for maternal absence and 1.61 (1.44-1.80) for paternal absence. Similarly, the refusal or delay in receiving the first-dose varicella vaccine was associated with an adjusted odds ratio of 2.04 (95% confidence interval, 1.01-4.16) for maternal absence and 1.37 (1.12-1.69) for paternal absence. The presence of siblings and maternal comorbidities were significantly associated with vaccination delays. CONCLUSION: The absence of a parent, the presence of siblings, and maternal comorbidities were associated with the refusal or delay in receiving measles-rubella and varicella vaccines. Strategies for vaccine recommendation should therefore consider family structure and maternal comorbidities.

Although large-scale administrative databases may be useful for studies of infectious diseases, conventional databases lack microbiological data. To illustrate the applicability of the National Hospital Organization Clinical Data Archives, a novel database of electronic medical records in Japan, we conducted a descriptive study of the microbiological findings in patients with community-acquired pneumonia using the database. We identified patients aged ≥18 years who were hospitalized for community-acquired bacterial pneumonia between April 2016 and March 2019. We evaluated the results of bacterial culture and antibacterial susceptibility of specimens obtained on the first day of hospitalization, in addition to patient characteristics, diagnosis codes, and intravenous antibiotics administered. The analysis identified 2200 eligible patients from 15 hospitals. Sulbactam-ampicillin was the most frequently used initial antibiotic (32 %), followed by ceftriaxone (22 %) and tazobactam-piperacillin (19 %). Overall, 56 %, 95 %, 56 %, and 73 % of patients with pathogen-specific diagnosis codes in the database for Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa, respectively, also tested positive for the corresponding pathogen in their sputum or blood cultures. Antibacterial susceptibilities were consistent with a previous report from Japan; 81 % of S. pneumoniae cases were resistant to azithromycin, and 48 % of H. influenzae cases were resistant to ampicillin. These microbiological characteristics warrant the future use of this database for detailed real-world research on infectious diseases.

BACKGROUND: Anti-glomerular basement membrane (anti-GBM) disease is treated with immunosuppressive medications and plasma exchange. However, whether plasma exchange, in addition to pulse glucocorticoid therapy, would benefit patients with anti-GBM disease with dialysis-dependent kidney failure without diffuse alveolar hemorrhage remains unclear. METHODS: Using the Japanese Diagnosis Procedure Combination database, we identified patients diagnosed with anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage from July 2010 to March 2020. We compared in-hospital mortality within 10 days of hospitalization between patients who received therapeutic plasma exchange in addition to pulse glucocorticoid therapy and those who received pulse glucocorticoid therapy alone. Overlap weighting based on propensity score was performed to adjust for potential confounders. RESULTS: We identified 207 eligible patients; 168 patients received therapeutic plasma exchange plus pulse glucocorticoid therapy, while 39 patients received pulse glucocorticoid therapy alone. The mean dose of therapeutic plasma exchange was 52.2 ml/kg/day of albumin and/or fresh frozen plasma. Therapeutic plasma exchange in addition to pulse glucocorticoid therapy was associated with a lower in-hospital mortality risk in the unweighted (10.7% versus 28.2%; risk difference, 17.5%; 95% confidence interval, 2.6-32.4%; P = 0.02) and weighted analyses (11.5% versus 28.4%; risk difference, 17.0%; 95% confidence interval, 1.5-32.5%; P = 0.03) than pulse glucocorticoid therapy alone. CONCLUSIONS: This retrospective cohort study using a national database suggests that therapeutic plasma exchange may improve the in-hospital prognosis of anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage.

Abstract Aim Kakkonto, a Japanese herbal kampo medicine, is empirically prescribed to improve milk stasis and ameliorate breast inflammation in patients with noninfectious mastitis. We investigated whether early use of kakkonto is associated with a reduction in antibiotic use and surgical drainage in patients with noninfectious mastitis. Methods We identified 34 074 patients with an initial diagnosis of noninfectious mastitis within 1 year of childbirth between April 2012 and December 2022 using the nationwide administrative JMDC Claims Database. Patients were divided into the kakkonto (n = 9593) and control (n = 9648) groups if they received and did not receive kakkonto on the day of the initial diagnosis of noninfectious mastitis, respectively. Antibiotic administration and surgical drainage within 30 days after the initial diagnosis of noninfectious mastitis in the two groups were compared using propensity score‐stabilized inverse probability of treatment weighting analysis. Results The frequency of antibiotic administration within 30 days after the initial diagnosis of noninfectious mastitis was significantly lower in the kakkonto group than in the control group (10% vs. 12%; odds ratio, 0.88 [95% confidence interval, 0.80–0.96]). The frequency of antibiotic administration during 1–3 and 4–7 days after the initial diagnosis were also significantly lower in the kakkonto group than in the control group. The frequency of surgical drainage did not differ significantly between the two groups. Conclusions Kakkonto was associated with reduced administration of antibiotics for noninfectious mastitis, making it a potential treatment option for relieving breast inflammation and promoting antimicrobial stewardship.

INTRODUCTION: The association between the use of cilostazol as a post-stroke antiplatelet medication and a reduction in post-stroke pneumonia has been suggested. However, whether cilostazol has a greater preventive effect against post-stroke aspiration pneumonia (AP) than other antiplatelet medications remains unclear. Thus, this study aimed to evaluate whether cilostazol has a greater preventive effect against post-stroke AP than aspirin or clopidogrel. METHODS: Through the Japanese Diagnosis Procedure Combination database, we identified patients who were hospitalized for ischemic stroke between April 2012 and September 2019. We performed 1:1 propensity score matching between patients who received cilostazol alone at discharge and those who received aspirin or clopidogrel alone at discharge. The primary outcome was the 90-day readmission for post-stroke AP. The occurrence of recurrent ischemic stroke within 90 days was also evaluated. RESULTS: Among the 305,543 eligible patients with ischemic stroke, 65,141 (21%), 104,157 (34%), and 136,245 (45%) received cilostazol, aspirin, and clopidogrel, respectively. Propensity score matching generated 65,125 pairs. The cilostazol group had a higher proportion of 90-day post-stroke readmissions with AP than the aspirin or clopidogrel groups (1.5% vs. 1.2%, p &lt; 0.001). The proportion of patients with recurrent ischemic stroke within 90 days was also higher in the cilostazol group (2.4% vs. 2.2%, p = 0.017). CONCLUSION: The present study suggests that cilostazol may not have a greater effect on preventing post-stroke AP within 90 days than other antiplatelet medications. Nevertheless, further randomized controlled trials with longer follow-up periods are warranted.

BACKGROUND: Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease. This study aimed to clarify the status of HRS in Japan by analyzing the Japanese Diagnosis Procedure Combination database. METHODS: Patients hospitalized for cirrhosis and HRS from July 2010 to March 2019 were sampled. They were divided into two groups according to their prognosis upon discharge: the transplant-free survival group and the death or liver transplantation group. The two groups' baseline patient characteristics and treatments were compared. RESULTS: The mean age of the 1,412 participants was 67.3 years (standard deviation: 12.3 years), and 65.4% were male. The Child-Pugh grades was B and C in 18.8% and 81.2%, respectively. Hepatocellular carcinoma was present in 27.1% of the patients, and the proportion of spontaneous bacterial peritonitis was 2.3%. Albumin, noradrenaline, and dopamine were administered to 57.9%, 8.0%, and 14.9% of the patients, respectively; 7.0% of the patients underwent renal replacement therapy; and 5.0% were admitted to the intensive care unit. Intravenous antibiotics were administered to 30.8% of the patients. A total of 925 patients (65.5%) died or underwent liver transplantation. In addition to a higher proportion of patients with poor baseline liver function, the death or liver transplantation group included more males, patients with hepatocellular carcinoma, and those with spontaneous bacterial peritonitis. CONCLUSIONS: HRS in Japan has a high mortality rate. Albumin was administered to over 50% of participants. Although noradrenaline is recommended in Japanese clinical guidelines, dopamine was more frequently used as a vasoconstrictor in clinical practice.

AIMS: We aimed to explore the association between short-term exposure to temperature variability (TV), and cardiovascular hospitalization stratified by the presence of comorbid diabetes. METHODS: We collected data on nationwide hospitalization for cardiovascular diseases and daily weather conditions during 2011-2018 in Japan. TV was calculated as the standard deviation of daily minimum and maximum temperatures within 0-7 lag days. We applied a two-stage time-stratified case-crossover design to estimate the association between TV and cardiovascular hospitalization with and without comorbid diabetes, adjusting for temperature and relative humidity. Furthermore, specific cardiovascular disease causes, demographic characteristics, and seasons were used for stratification. RESULTS: In 3,844,910 hospitalizations for cardiovascular disease, each 1°C increase in TV was associated with a 0.44% (95% CI: 0.22%-0.65%) increase in the risk of cardiovascular admission. We observed a 2.07% (95% CI: 1.16%-2.99%) and 0.61% (95% CI: -0.02%-1.23%) increase per 1°C in risk of heart failure admission in individuals with and those without diabetes, respectively. The higher risk among individuals with diabetes was mostly consistent in the analyses stratified by age, sex, body mass index, smoking status, and season. CONCLUSION: Comorbid diabetes may increase susceptibility to TV in relation to acute cardiovascular disease hospitalization.

AIM: Hypnotics might increase the risk of falls and fractures in older patients with neurocognitive disorders. Orexin receptor antagonists have recently been approved, but the relationship between the new drugs and fractures remains unclarified. This study aimed to evaluate the association between the type of hypnotic and in-hospital fractures in older patients with neurocognitive disorders using a nationwide inpatient database. METHODS: Using the Japanese Diagnosis Procedure Combination database, we collected information on inpatients aged ≥65 years with neurocognitive disorders between April 2014 and March 2021. We examined trends in the prescription patterns of benzodiazepine drugs, Z-drugs, orexin receptor antagonists and melatonin receptor agonists. We also carried out a 1:4 matched case-control analysis of in-hospital fractures. The odds ratio of each hypnotic drug was estimated using a generalized estimating equation with adjustment for walking ability, comorbidities, osteoporosis, dialysis, selective serotonin reuptake inhibitor use and anti-dementia drug use. RESULTS: The prescription of benzodiazepine hypnotics decreased and that of orexin receptor antagonists increased. This case-control analysis included 6832 patients with fractures and 23 463 controls. Ultrashort-acting benzodiazepines, short-acting benzodiazepines and Z-drugs were associated with an increased risk of bone fracture (odds ratio [95% confidence interval] 1.38 [1.08-1.77], 1.38 [1.27-1.50], 1.49 [1.37-1.61], respectively). Orexin receptor antagonists were not associated with an increased risk of bone fracture (1.07 [0.95-1.19]). CONCLUSIONS: In contrast to other types of hypnotics, orexin receptor antagonists were not associated with in-hospital fractures in older patients with neurocognitive disorders. Geriatr Gerontol Int 2023; ••: ••-••.

BACKGROUND: Validating the information recorded in administrative databases is essential. However, no study has comprehensively validated the accuracy of Japanese Diagnosis Procedure Combination (DPC) data on various respiratory diseases. Therefore, this study aimed to evaluate the validity of diagnoses of respiratory diseases in the DPC database. METHODS: We conducted chart reviews of 400 patients hospitalized in the departments of respiratory medicine in two acute-care hospitals in Tokyo, between April 1, 2019 and March 31, 2021, and used them as reference standards. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DPC data on 25 respiratory diseases were determined. RESULTS: Sensitivity ranged from 22.2% (aspiration pneumonia) to 100% (chronic eosinophilic pneumonia and malignant pleural mesothelioma) and was <50% for eight diseases, while specificity was >90% for all diseases. PPV ranged from 40.0% (aspiration pneumonia) to 100% (coronavirus disease 2019, bronchiectasis, chronic eosinophilic pneumonia, pulmonary hypertension, squamous cell carcinoma, small cell carcinoma, lung cancer of other histological types, and malignant pleural mesothelioma) and was >80% for 16 diseases. Except for chronic obstructive pulmonary disease (82.9%) and interstitial pneumonia (other than idiopathic pulmonary fibrosis) (85.4%), NPV was >90% for all diseases. These validity indices were similar in both hospitals. CONCLUSIONS: The validity of diagnoses of respiratory diseases in the DPC database was high in general, thereby providing an important basis for future studies.

Abstract Background Influenza-related bacterial pneumonia is a leading complication of influenza infection. However, the differences in the incidence rates and risk factors associated with concomitant viral/bacterial pneumonia (CP) and secondary bacterial pneumonia following influenza (SP) remain unclear. This study aimed to clarify the incidence rates of CP and SP following seasonal influenza and identify factors associated with their development. Methods This retrospective cohort study was conducted using the JMDC Claims Database, a health insurance claims database in Japan. All patients aged &amp;lt;75 years who developed influenza during 2 consecutive epidemic seasons 2017/2018 and 2018/2019 were analyzed. CP was defined as bacterial pneumonia diagnosed between 3 days before and 6 days after the date of influenza diagnosis, and SP was defined as pneumonia diagnosed 7–30 days after the date of diagnosis. Multivariable logistic regression analyses were performed to identify factors associated with the development of CP and SP. Results Among the 10,473,014 individuals registered in the database, 1,341,355 patients with influenza were analyzed. The average age at diagnosis was 26.6 (standard deviation, 18.6) years. There were 2,901 (0.22%) and 1,262 (0.09%) patients who developed CP and SP, respectively. Aged 65–74 years, asthma, chronic bronchitis/emphysema, cardiovascular disease, renal disease, malignant tumor, and immunosuppression were significant risk factors for both CP and SP, whereas cerebrovascular disease, neurological disease, liver disease, and diabetes were risk factors specific for CP development. Conclusions The results determined the incidence rates of CP and SP and identified their risk factors, such as older age and comorbidities.

OBJECTIVES: The effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in preventing pneumonia in older adults remains controversial. Some studies have suggested differences in the effectiveness according to age or sex. METHODS: We conducted an observational study using the database of vaccine subsidisation data and health insurance claims data for a city in Japan. Participants were residents from 2014 to 2018 turning 65, 70, 75, 80, 85, 90 or 95 years during a given fiscal year, and PPV23 during the first year of observation were identified. We matched vaccinated and non-vaccinated individuals of the same age using propensity scores for vaccination. Incidence of hospitalisation with pneumonia was compared using Fine-Gray regression model. We summarised the results for each age using random-effects meta-analysis and conducted a subgroup analysis by sex. RESULTS: A total of 102,136 participants were included, of whom 35% received PPV23. Propensity score matching selected 32,510 pairs of vaccinated and non-vaccinated individuals. Overall, PPV23 administration was associated with a decreased incidence of hospitalisation with pneumonia (17.2 vs. 20.4 per 1,000 person-years, sub-distribution hazard ratio: 0.84, 95% confidence interval: 0.77 to 0.91). Vaccine effectiveness was highest among those aged 70 years and decreased with increasing age. No statistically significant effect was observed in those aged 90 or 95 years. Vaccine effectiveness was observed in both males and females. CONCLUSIONS: PPV23 was associated with an overall decrease in hospitalisation with pneumonia in older adults. However, vaccine effectiveness was significant in those aged 65 to 85 years but not in older population.

BACKGROUND: The immune response to influenza vaccination in the elderly is likely to be lower than that in young adults. Clinical protection may not persist year-round in the elderly. However, the effectiveness of influenza vaccine in the elderly has not been adequately studied, especially in terms of the duration of effectiveness. METHODS: We used a linked database of healthcare administrative claims data and vaccination records maintained by the municipality of a city in Kanto region of Japan. We studied individuals who were aged 65 years or older at baseline and were followed up between April 1, 2014 to March 31, 2020. The duration of influenza vaccine effectiveness by age category was analyzed using a time-dependent piecewise Cox proportional hazard model with time-dependent vaccine status, prior season vaccination and covariates confirmed in the baseline period (age, sex, cancer, diabetes, chronic obstructive pulmonary diseases, asthma, chronic kidney diseases, and cardiovascular diseases). RESULTS: We identified an analysis population of 83,146 individuals, of which 7,401 (8.9%) had experienced influenza and 270 (0.32%) underwent influenza-related hospitalization. Individuals who were vaccinated during the first season (n = 47,338) were older than non-vaccinated individuals (n = 35,808) (average age, 75.8 vs. 74.1 years, respectively). The multivariable analysis showed a lower incidence of influenza in vaccinated individuals (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.43-0.51; P < 0.001), while the incidence of hospitalization for influenza did not differ significantly by vaccination status (HR, 0.79; 95% CI, 0.53-1.18; P = 0.249). Protective effectiveness against incidence was maintained for 4 or 5 months after vaccination in those aged 65-69 and 80-years, 5 months in 70-79 years. CONCLUSIONS: Our study identified moderate vaccine effectiveness in preventing the incidence of influenza in the Japanese elderly. Vaccine effectiveness showed a trend of gradual attenuation. Clinicians should suspect influenza infection even in those vaccinated, especially in elderly individuals who had received vaccination more than 4 or 5 months previously.

BACKGROUND: Substantial evidence suggests that non-optimal temperatures can increase the risk of cardiovascular disease (CVD) mortality and morbidity; however, limited studies have reported inconsistent results for hospital admissions depending on study locations, which also lack national-level investigations on cause-specific CVDs. METHODS: We performed a two-stage meta-regression analysis to examine the short-term associations between temperature and acute CVD hospital admissions by specific categories [i.e., ischemic heart disease (IHD), heart failure (HF), and stroke] in 47 prefectures of Japan from 2011 to 2018. First, we estimated the prefecture-specific associations using a time-stratified case-crossover design with a distributed lag nonlinear model. We then used a multivariate meta-regression model to obtain national average associations. RESULTS: During the study period, a total of 4,611,984 CVD admissions were reported. We found cold temperatures significantly increased the risk of total CVD admissions and cause-specific categories. Compared with the minimum hospitalization temperature (MHT) at the 98th percentile of temperature (29.9 °C), the cumulative relative risks (RRs) for cold (5th percentile, 1.7 °C) and heat (99th percentile, 30.5 °C) on total CVD were 1.226 [95% confidence interval (CI): 1.195, 1.258] and 1.000 (95% CI: 0.998, 1.002), respectively. The RR for cold on HF [RR = 1.571 (95% CI: 1.487, 1.660)] was higher than those of IHD [RR = 1.119 (95% CI: 1.040, 1.204)] and stroke [RR = 1.107 (95% CI: 1.062, 1.155)], comparing to their cause-specific MHTs. We also observed that extreme heat increased the risk of HF with RR of 1.030 (95% CI: 1.007, 1.054). Subgroup analysis showed that the age group ≥85 years was more vulnerable to these non-optimal temperature risks. CONCLUSIONS: This study indicated that cold and heat exposure could increase the risk of hospital admissions for CVD, varying depending on the cause-specific categories, which may provide new evidence to reduce the burden of CVD.

BACKGROUND: Despite the widespread practice of Japanese traditional Kampo medicine, the characteristics of patients receiving various Kampo formulations have not been documented in detail. We applied a machine learning model to a health insurance claims database to identify the factors associated with the use of Kampo formulations. METHODS: A ten-percent sample of enrollees of the JMDC Claims Database in 2018 and 2019 was used to create the training and testing sets, respectively. Logistic regression with lasso regularization were performed in the training set to construct models with prescriptions of 10 commonly used Kampo formulations in one year as the dependent variable and data of the preceding year as independent variables. Models were applied to the testing set to calculate the C-statistics. Additionally, the performance of simplified scores using 10 or 5 variables were evaluated. RESULTS: There were 338,924 and 399,174 enrollees in the training and testing sets, respectively. The commonly prescribed Kampo formulations included kakkonto, bakumondoto, and shoseityuto. Based on the lasso models, the C-statistics ranged from 0.643 (maoto) to 0.888 (tokishakuyakusan). The models identified both the common determinants of different Kampo formulations and the specific characteristics associated with particular Kampo formulations. The simplified scores were slightly inferior to full models. CONCLUSIONS: Lasso regression models showed good performance for explaining various Kampo prescriptions from claims data. The models identified the characteristics associated with Kampo formulation use.

BACKGROUND: Several studies have demonstrated the efficacy of prednisolone and cyclosporine as initial combination treatments for the prevention of coronary artery abnormalities (CAA) in patients with Kawasaki disease. However, whether prednisolone or cyclosporine results in superior clinical outcomes is unknown. Thus, this study aimed to compare the outcomes of these two treatments. METHODS: Using the Japanese Diagnosis Procedure Combination database, we identified patients with Kawasaki disease who had received prednisolone or cyclosporine in addition to initial intravenous immunoglobulin treatment between April 2014 and March 2021. The primary outcome was the proportion of CAA; secondary outcomes included intravenous immunoglobulin resistance, medical costs, and length of hospital stay. Propensity score matching was conducted to compare outcomes between the two groups. RESULTS: We identified 6288 patients with Kawasaki disease who had received prednisolone (n = 6147) or cyclosporine (n = 141) as an initial treatment in combination with intravenous immunoglobulin. Four-to-one propensity score-matched analysis demonstrated no significant difference in the proportion of CAA (0.7% vs. 2.8%; p = 0.098), intravenous immunoglobulin resistance, or medical costs between the treatment groups. The length of hospital stay was significantly longer in the prednisolone group (14 vs. 11 days, p < 0.001). CONCLUSIONS: Prednisolone and cyclosporine used in the initial combination treatment for Kawasaki disease showed similar clinical outcomes regarding the risk of CAA, intravenous immunoglobulin resistance, and medical costs, whereas the length of hospital stay was longer in the prednisolone group than in the cyclosporine group.

Proteinuria is a major side-effect of the anti-tumor drug bevacizumab, although its incidence and risk factors in the real world are still unclear. Although renin-angiotensin-aldosterone system inhibitors are used clinically to prevent proteinuria, their efficacy remains unclear. The aim of the present study was to reveal the incidence and risk factors of bevacizumab-induced proteinuria and examine the effectiveness of antihypertensive drugs in preventing proteinuria. We conducted a retrospective cohort study using the National Hospital Organization Clinical Data Archives and Medical Information Analysis Databank. Hospitalized patients who received bevacizumab between January 1, 2016, and June 30, 2019, were included. The study outcome was proteinuria within 12 months of bevacizumab administration. Patient characteristics, laboratory tests, and medications were compared between patients with and without proteinuria using multivariable logistic regression analysis. Among the 2,458 patients, 27% developed proteinuria after bevacizumab administration. Nursing dependence (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.89-3.05; P<0.001) and systolic blood pressure ≥140 mmHg (OR, 1.44; 95% CI, 1.17-1.79; P<0.001) were identified as risk factors. Patients with an estimated glomerular filtration rate (eGFR) of 60-89, 45-59, and <45 mL/min/1.73 m2 had 29.7%, 76.8%, and 66.0% higher odds of proteinuria, respectively, than those with an eGFR ≥90 mL/min/1.73 m2. No significant relationship was observed between antihypertensive drugs and the occurrence of proteinuria. More patients may suffer from proteinuria after bevacizumab administration than previously reported. Nursing dependence and systolic blood pressure are predictive risk factors for bevacizumab-induced proteinuria. Patients at risk of proteinuria should be closely monitored.

OBJECTIVE: It remains unclear which factors contribute to dysphagia recovery after an acute stroke. This study aimed to identify factors associated with complete oral intake recovery in patients with post-stroke dysphagia. METHODS: Data were obtained from the Diagnosis Procedure Combination database, which is a nationwide database of administrative claims and discharge abstracts in Japan. We selected patients admitted within 3 days of stroke onset and conducted multivariable logistic regression analysis. Total oral intake within 30 days of admission was the primary outcome measure. RESULTS: A total of 151,302 patients were included, and total oral intake was observed in 48% of them within 30 days of admission. Total oral intake was significantly associated with age, sex, stroke subtype, consciousness disturbance, low body mass index, multiple comorbidities, and the modified Rankin Scale before stroke onset. In addition, males had worse outcomes than females (odds ratio, 0.75; 95% confidence interval, 0.73-0.77, p < 0.001), and intracerebral and subarachnoid hemorrhagic stroke subtypes were associated with non-recovery. CONCLUSION: This study identified several prognostic factors for total oral intake in patients with acute stroke. These results may be useful for predicting a patient's dysphagia prognosis at the time of admission and designing a nutritional management plan for patients with acute stroke.

OBJECTIVE: To clarify the fetal safety of herbal Kampo medicines, including Hange-koboku-to, Koso-san, Nyoshin-san, Yokukansan, Yokukansan-kachinpi-hange, Saiko-keishikankyo-to, Keishi-karyukotu-borei-to, and Kanbaku-taisou-to, when administered to pregnant women with depression using a large healthcare administrative database. METHODS: We extracted data from the JMDC Claims Database (2005-2018) for this retrospective cohort study of pregnant women aged 19 years or older admitted to obstetric clinics or hospitals for delivery. Participants were classified into four groups: those without depression, those diagnosed with depression without medication, those given Kampo medicines for depression, and those given western medicines for depression. Neonatal outcomes (congenital anomalies, low birth weight, and preterm birth) were considered as the safety outcome measures. RESULTS: We identified 179 707 eligible mothers. The adverse outcomes did not differ significantly between participants receiving Kampo medicine and those not diagnosed with depression during pregnancy. The proportion of low-birth-weight neonates did not differ significantly between the Kampo medicine and non-depression groups (adjusted odds ratio [aOR] 1.28; 95% confidence interval [CI] 0.86-1.91), but was significantly higher in the unmedicated depression group (aOR 1.31; 95% CI 1.07-1.61) and western medicine group (aOR 1.47; 95% CI 1.18-1.83). CONCLUSION: Kampo medicines are safe for treating depression during pregnancy without increasing the incidence of congenital anomalies, low birth weight, or preterm birth.

OBJECTIVES: Although amoxicillin is the first-line prophylactic drug for impacted mandibular third molar extraction, third-generation cephalosporins are widely prescribed in Japan. The lack of real-world evidence may be one reason for this inappropriate use. We evaluated differences in the incidence of surgical site infection between amoxicillin and third-generation cephalosporins for impacted mandibular third molar extraction. METHODS: Using the JMDC Claims Database, we identified dental visits with fully or horizontally impacted mandibular third molar extraction from April 2015 to March 2020. One-to-one propensity-score matching was conducted between amoxicillin and third-generation cephalosporin groups. The incidence of surgical site infection following extraction was compared in the matched pairs using McNemar's test. RESULTS: We identified 109,266 dental visits, including 39,514 (36.2%) patients who received amoxicillin and 69,752 (63.8%) patients who received third-generation cephalosporins. In the 39,514 matched pairs, the incidence of surgical site infection was 3.5% (n = 1399) for amoxicillin group and 3.7% (n = 1467) for third-generation cephalosporin group (p = 0.003). CONCLUSIONS: Amoxicillin was associated with a lower incidence of surgical site infection after impacted mandibular third molar extraction compared with third-generation cephalosporins. This result supports current guidelines and strengthens the importance of disseminating and implementing antimicrobial resistance control in dentistry.

PURPOSE: To investigate the risk of ocular adverse events after Coronavirus Disease 2019 (COVID-19) mRNA vaccination. DESIGN: Matched cohort and self-controlled case series (SCCS) studies. PARTICIPANTS: We used a population-based database of medical claims and vaccination records in a large Japanese city. In the matched cohort study, we identified individuals who received COVID-19 vaccination (BNT162b2) from February 2021 to September 2021. One control was selected from nonvaccinated individuals by matching time, date of birth, sex, Charlson comorbidity index, and the enrollment period for health insurance. In the SCCS study, we analyzed individuals who developed ocular adverse events. METHODS: In the matched cohort study, we applied the Kaplan-Meier estimator to estimate the cumulative incidence of ocular adverse events over 21 days after the first dose and 84 days after the second dose. In the SCCS method, we used conditional Poisson regression to estimate the incidence rate ratio (IRR) of ocular adverse events during the risk periods (0-21 days after the first dose and 0-84 days after the second dose) compared with the remaining periods. MAIN OUTCOME MEASURES: Composite outcome of uveitis, scleritis, retinal vein occlusion (RVO), and optic neuritis. RESULTS: There were 99 718 pairs eligible for the matched cohort study after the first dose (mean age, 69.3 years; male, 44%). The vaccinated and control groups developed 29 and 21 events, respectively, over 21 days after the first dose, and 79 and 28 events, respectively, over 84 days after the second dose. The differences in cumulative incidence (reference, the control group) were 2.9 (95% confidence interval, -14.5 to 19.1) events/100 000 persons and 51.3 (16.2-84.3) events/100 000 persons, respectively, for the first and second doses. The SCCS study showed the IRRs of 0.89 (0.62-1.28) and 0.89 (0.71-1.11) for the first and second doses, respectively. CONCLUSIONS: The matched cohort analysis found an increased risk for the composite outcome after the second dose; however, the SCCS analysis showed no increased risk. Considering that the SCCS can cancel out time-invariant confounders, the current results suggest that COVID-19 vaccination is unlikely to causally increase the risk of ocular adverse events. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

PURPOSE: To evaluate the validity of operative information recorded in the Diagnosis Procedure Combination (DPC) database, a national inpatient database including administrative claims data. METHODS: We reviewed the medical charts of 1221 patients who underwent one of six surgeries (breast, esophageal, gastric, thyroid cancer surgery, appendectomy, or inguinal hernia repair) at a surgery department of a university hospital from April 2016 to March 2019. We compared operative information (type, date, laterality of procedure; type of anesthesia; transfusion; and duration of anesthesia) recorded in the DPC database with the information recorded in the medical charts. RESULTS: The DPC data for type, date, laterality of surgery, and type of anesthesia were accurate in 99% of the reviewed patients. The sensitivity and specificity for identifying whether a patient received a transfusion procedure were 97.5% and 99.6%, respectively. Data regarding the duration of anesthesia in the DPC database were identical to those in medical chart records in 1114 of 1216 cases that received general or spinal anesthesia (91.5%). The duration of anesthesia in the DPC data was 53 min longer on average than the recorded operative time in the medical charts. CONCLUSION: The DPC database had high validity for operative information.

BACKGROUND: Direct comparative effectiveness of booster doses of BNT162b2 and mRNA-1273 after BNT162b2 primary vaccination is unknown. METHODS: We investigated comparative effectiveness of BNT162b2 and mRNA-1273 booster dose using data from registry systems for vaccination and COVID-19 infection in a local city in Japan. We followed participants aged ≥16 years who completed the BNT162b2 primary vaccination between November 22, 2021, and April 15, 2022. We collected information on age, sex, vaccination status, vaccine type, and infection status. Age was categorized as 16-44, 45-64, 65-84, and ≥85 years. Vaccine effectiveness for mRNA-1273 and no booster vaccination against BNT162b2 was estimated using age-stratified Cox regression adjusted for age, sex, and days since the second vaccination. The estimated hazard ratios for mRNA-1273 and no booster vaccinations were integrated separately using random effects meta-analyses. RESULTS: During the study period, we identified 62,586 (40.4%), 51,490 (33.2%), and 40,849 (26.4%) participants who received BNT162b2, mRNA-1273, and no booster dose, respectively. The median age was 69, 71, and 47 years for BNT162b2, mRNA-1273, and no booster dose, respectively. The integrated hazard ratio with reference to BNT162b2 was 1.72 for no booster vaccination and 0.62 for mRNA-1273. The comparative effectiveness of mRNA-1273 was similar across age categories. CONCLUSIONS: Both homologous and heterologous vaccinations are effective against Omicron variants. In the head-to-head comparison, the effect was stronger in people who received heterologous vaccination than in those who received homologous vaccination. These findings may help improve logistics and decision making in future vaccination programs.

Pediatric cardiac catheterization requires unconsciousness and immobilization through general anesthesia or sedation. This study aimed to compare the occurrence of severe complications in pediatric diagnostic cardiac catheterization for ventricular septal defect between general anesthesia and sedation performed under similar institutional environments. Using the Japanese Diagnosis Procedure Combination database, we retrospectively identified pediatric patients (aged &lt;2 years) who underwent diagnostic cardiac catheterization for ventricular septal defect between July 2010 and March 2019. The composite outcome was the occurrence of severe complications, including catecholamine use and intensive care unit admission, within seven days after catheterization. Overlap weighting based on propensity scores was used to adjust for patient- and hospital-level confounding factors. We identified 3159 patients from 87 hospitals, including 930 under general anesthesia and 2229 under sedation. The patient- and hospital-level baseline characteristics differed between the groups. After adjustment, the proportion of patients with severe complications was significantly higher in the general anesthesia group than in the sedation group (2.4% vs. 0.6%; risk difference, 1.8% [95% confidence interval, 0.93-2.6%]). Severe complications occurred more frequently in the general anesthesia group than in the sedation group. Further research on anesthetic methods is necessary to assess the safety and accuracy of pediatric diagnostic cardiac catheterization.

Background: Polypharmacy and its adverse drug events are a major healthcare challenge related to falls, hospitalisations and mortality. Comprehensive geriatric assessment (CGA) may contribute to polypharmacy improvement, however, there is no clear evidence so far. Methods: Using a national inpatient database in Japan from April 1, 2014 to March 31, 2018, we investigated the association between CGA and polypharmacy. We identified patients aged ≥65 years admitted for ischaemic stroke who could receive oral medications. Propensity score matching was conducted for patients with and without CGA during hospitalisation. The outcomes were polypharmacy (defined as use of five or more types of oral medications) at discharge, the number of medication types prescribed at discharge, and the difference between the numbers of medication types prescribed on admission and at discharge. Findings: A total of 162,443 patients were analysed, of whom 39,356 (24·2%) received CGA, and propensity score matching identified 39,349 pairs. Compared with non-CGA group, the CGA group had a significantly lower proportion of polypharmacy at discharge (34·3% vs. 32·9%, p < 0·001) and a smaller number of medication types prescribed at discharge (3·84 vs. 3·76, p < 0·001). Interpretation: This study shows the clear evidence that there is a positive relationship between CGA and a reduction in the number of medications in older inpatients with ischaemic stroke. Funding: The Ministry of Health, Labour and Welfare, Japan and the Ministry of Education, Culture, Sports, Science and Technology, Japan.

INTRODUCTION: To describe patterns in antibiotic prophylaxis for tooth extraction following the 2016 Japanese National Action Plan on Antimicrobial Resistance. METHODS: Using a health insurance claims database, we retrospectively identified tooth extraction visits by patients aged ≥18 years from September 2015 to August 2018 and classified patients as undergoing extraction of a fully impacted or horizontally impacted mandibular wisdom tooth, being at risk of infective endocarditis or surgical site infection, or being at low risk. Antibiotic use and type of antibiotics prescribed on the day of tooth extraction were evaluated across the study period, with stratification by tooth extraction category and facility type (hospital or dental clinic). RESULTS: We identified 662,435 patients with tooth extraction. The mean age was 42.7 years, and 57% were male. Twelve percent underwent wisdom tooth extraction, 32% were high risk, and 10% visited hospitals. The proportion of antibiotic use was 83% overall and 82% among low-risk patients. This proportion remained similar throughout the study period. A shift from third-generation cephalosporins to amoxicillin was observed from 2015 to 2018: the proportion prescribed third-generation cephalosporins decreased from 58% to 34% in hospitals and from 57% to 56% in clinics, and the proportion prescribed amoxicillin increased from 16% to 37% in hospitals and from 6% to 10% in clinics. CONCLUSIONS: The pattern of prophylactic antibiotic use for tooth extraction gradually changed after the initiation of the National Action Plan. Further efforts are required to reduce potentially inappropriate prescriptions for low-risk patients, especially in dental clinics.

PURPOSE: Although subcutaneous steroid injections are conventionally used to treat extravasation of vesicant anticancer drugs, their effects on the extravasation site remain unclear. We investigated the association between subcutaneous steroid injection in patients with extravasation of vesicant anticancer drugs and incidence of skin ulcers requiring surgery. METHODS: We performed a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database. We identified patients with extravasation of vesicant anticancer drugs who were prescribed steroid ointment or cream on the same day as vesicant drug use between July 2010 and March 2019. The exposure group consisted of patients who had received subcutaneous steroid injections and local anesthetic in addition to topical steroids, whereas the control group had received topical steroids alone. The outcome was the incidence of skin surgical procedures during hospitalization. We performed a mixed-effect logistic regression analysis with random intercept for each hospital to compare outcomes between the groups. RESULTS: We identified 7284 patients from 704 hospitals, including 3713 patients who had received topical steroids alone and 3571 who had received subcutaneous steroid injection in addition to topical steroids. According to mixed-effect logistic regression analysis, subcutaneous steroid injection was significantly associated with a higher incidence of skin surgery (odds ratio, 1.61; 95% confidence interval, 1.14-2.26; P = 0.007). Barthel Index, type of cancer, and type of vesicant drugs were also associated with surgery. CONCLUSIONS: Subcutaneous steroid injections after extravasation of vesicant anticancer drugs are associated with more frequent skin surgery. Randomized controlled trials are required to evaluate the safety and effectiveness of steroid injection.

Objective: The aim of this study was to identify factors associated with requiring surgical treatment for mastitis or breast abscess in postpartum mothers. Materials and Methods: This was a retrospective cohort study using the Japan Medical Data Center Claims Database. Information on pairs of infants born between April 2012 and December 2016 and their mothers were extracted. Data regarding the baseline characteristics, medical history, medical practice, and prescription drugs of mothers and their infants were collected. Multivariable logistic regression analysis was used to examine factors associated with undergoing surgical treatment. Results: The data of 69,363 eligible mothers were analyzed. The proportion of mothers who were diagnosed with mastitis or breast abscess within 1 year after childbirth was 10.8% (7,516/69,363). There were 114 mothers who underwent surgical treatment within 1 year after childbirth. This was 0.2% of all mothers and 1.5% of those diagnosed with mastitis or breast abscess. Surgical treatment was significantly associated with mothers having their first child (adjusted odds ratio [AOR], 2.58; 95% confidence interval [CI], 1.63-4.07) compared to those with a second or later child; it was also significantly associated with the diagnosis of breast abscess (AOR, 10.38; 95% CI, 5.28-20.40). Conclusions: This was the first report of the prevalence of mastitis or breast abscess and the requirement for surgical treatment among postpartum mothers in Japan. A first diagnosis of breast abscess and having a first child were associated with requiring surgical treatment. Health care professionals providing postpartum care should be aware of these factors.

BACKGROUND: Administrative claims databases have been used widely in studies because they have large sample sizes and are easily available. However, studies using administrative databases lack information on disease severity, so a risk adjustment method needs to be developed. OBJECTIVE: We aimed to develop and validate deep learning-based prediction models for in-hospital mortality of acute care patients. METHODS: The main model was developed using only administrative claims data (age, sex, diagnoses, and procedures on the day of admission). We also constructed disease-specific models for acute myocardial infarction, heart failure, stroke, and pneumonia using common severity indices for these diseases. Using the Japanese Diagnosis Procedure Combination data from July 2010 to March 2017, we identified 46,665,933 inpatients and divided them into derivation and validation cohorts in a ratio of 95:5. The main model was developed using a 9-layer deep neural network with 4 hidden dense layers that had 1000 nodes and were fully connected to adjacent layers. We evaluated model discrimination ability by an area under the receiver operating characteristic curve (AUC) and calibration ability by calibration plot. RESULTS: Among the eligible patients, 2,005,035 (4.3%) died. Discrimination and calibration of the models were satisfactory. The AUC of the main model in the validation cohort was 0.954 (95% CI 0.954-0.955). The main model had higher discrimination ability than the disease-specific models. CONCLUSIONS: Our deep learning-based model using diagnoses and procedures produced valid predictions of in-hospital mortality.

BACKGROUND: Maoto is a Japanese Kampo formula used for treating febrile illnesses. However, researchers have not yet clarified its effect in preventing severe influenza among older adults. We evaluated the association between the addition of maoto to a neuraminidase inhibitor in older adults and reduced hospitalization following influenza. METHODS: Using a prefecture-wide health insurance claims database, we identified outpatients aged ≥60 years who were diagnosed with influenza between September 2012 and August 2017. We performed one-to-one propensity score matching between patients who received maoto in addition to a neuraminidase inhibitor and those who received a neuraminidase inhibitor alone. Hospitalization within 7 days of influenza diagnosis was compared using the McNemar's test. We performed subgroup analyses based on sex, age, and other characteristics. RESULTS: We identified 57,366 eligible patients with influenza. Maoto was used in 8.1% of these patients. In 4,630 matched pairs, the 7-day hospitalization rate was 1.77% (n = 82) and 1.62% (n = 75) for patients with and without maoto, respectively; the difference between the groups was insignificant (P = 0.569). Subgroup analysis showed a tendency toward more hospitalizations within 7 days among patients aged 90 years or older who were prescribed maoto than those who were not (9.7% vs. 6.6%, P = 0.257). CONCLUSIONS: Maoto use was not associated with decreased hospitalization rates in older adults with influenza. This warrants further research to evaluate the safety and effectiveness of maoto in different patient groups, particularly the oldest-old population.

AIM: Psychiatric disturbances are the major adverse effects of corticosteroids. There are no consistent conclusions regarding changes in steroid dosage and the incidence of psychiatric conditions, due in part to the lack of consistent evaluation criteria. The purpose of this research was to determine the incidence and dose-dependency of psychiatric conditions as assessed by trained psychiatrists. METHODS: A retrospective chart review was conducted at a university hospital in Japan. We identified inpatients receiving oral prednisolone treatment, who were referred to the consultation-liaison psychiatry team from April 2015 to March 2018. Patients were divided into high-dose (≥0.5 mg/kg/day) and low-dose (<0.5 mg/kg/day) groups. We investigated the associations between steroid dosage and incidence of psychiatric conditions. RESULTS: A total of 93 patients (35 in the high-dose group, 58 in the low-dose group) were included. Various psychiatric conditions, such as insomnia, delirium, depression, and psychosis, occurred during steroid therapy. The most common condition was insomnia (72%). We observed no significant differences in the patient background characteristics and the incidence of most psychiatric conditions between the high-dose and low-dose groups. However, there were more patients with delirium in the low-dose group than in the high-dose group. CONCLUSIONS: Based on the accurate assessment of psychiatric conditions by psychiatrists, our analysis suggests that, among inpatients referred to a consultation-liaison psychiatry team, the incidence of psychiatric conditions, with the exception of delirium, is independent of the dose of oral prednisolone.

<title>Abstract</title><sec> <title>Background</title> Dental claims data have been used for epidemiological studies without establishing the validity of the recorded diagnoses or procedures. The present study aimed to examine the accuracy of diagnoses, procedures, operation time, and the number of teeth recorded in dental claims data. </sec><sec> <title>Methods</title> We reviewed the charts of 200 patients who visited and 100 patients who were hospitalized in the Department of General Dentistry, Orthodontics, and Oral and Maxillofacial Surgery in an academic hospital between August 2012 and December 2017. The sensitivity and specificity of the dental claims data for five diseases and 15 procedures were evaluated. We assessed the difference in the number of teeth and duration of general anesthesia between claims data and chart reviews. </sec><sec> <title>Results</title> Sensitivity was more than 86% for six out of seven diagnoses except for pericoronitis (67%). Specificity ranged from 72% (periodontal disease) to 100% (oral cancer for inpatient). The sensitivity of procedures ranged from 10% (scaling for inpatient) to 100%, and the specificity ranged from 6% (food intake on the day of the surgery) to 100%. The mean (standard deviation [SD]) number of teeth in the chart review was 22.6 (6.8), and in the dental claims was 21.6 (8.6). The mean (SD) operation time was 171.2 (120.3) minutes, while the duration of general anesthesia was 270.9 (171.3) minutes. </sec><sec> <title>Conclusions</title> The present study is the first study to validate dental claims data, and indicates the extent of usefulness of each diagnosis and procedure for future dental research using administrative data. </sec>