山名 隼人

Irinotecan hydrochloride (CPT-11) is used to treat a wide spectrum of malignant tumors. Hangeshashin-to (Japanese herbal medicine TJ-14) is reportedly effective in preventing and controlling diarrhea associated with CPT-11. However, the effect of TJ-14 on tolerability of chemotherapy with CPT-11 has not been fully investigated. We used the Japanese Diagnosis Procedure Combination inpatient database to retrospectively identify patients who had received CPT-11 on their first admission with and without TJ-14. Patients who did receive TJ-14 (N = 7092) received CPT-11 more often and in larger doses than those who did not receive TJ-14 (N = 82,019). The incidence rate ratio of CPT-11 administration was 1.34 for frequency (95% confidence interval [CI], 1.31⁻1.38; p < 0.001), and 1.16 for total dose (95% CI, 1.14⁻1.19; p < 0.001) according to stabilized inverse probability treatment weighting using propensity scores. Instrumental variable analysis showed similar trends. In-hospital mortality was significantly lower in patients who received TJ-14 than in those who did not. Odds ratios of in-hospital death in patients receiving TJ-14 was 0.81 (95% CI, 0.71⁻0.93; p = 0.002) according to stabilized inverse probability treatment weighting using propensity scores and 0.42 (95% CI, 0.22⁻0.81; p = 0.009) according to instrumental variable analysis. Our findings indicate that TJ-14 improve the tolerability of CPT-11.

PURPOSE: Periprosthetic joint infection is a serious complication of total knee arthroplasty. Though there are many factors that might increase its risk, the use of propofol for maintaining general anesthesia could theoretically increase the incidence of infection because of its lipid component that supports bacterial growth. Nevertheless, the relationship between anesthetic maintenance agents and the occurrence of periprosthetic joint infection remains uncertain. The purpose of this study was to compare the incidence of suspected early-onset periprosthetic joint infection between patients undergoing total knee arthroplasty under propofol vs sevoflurane anesthesia. METHODS: We conducted a retrospective cohort study of patients in the national inpatient Diagnosis Procedure Combination database in Japan who underwent total knee arthroplasty. Suspected periprosthetic joint infection was surrogately defined as the need for arthrocentesis or debridement within 30 days of surgery. Propensity score matching was performed between patients who received either propofol or sevoflurane for anesthetic maintenance to determine the proportion of those with infection. RESULTS: Eligible patients (n = 21,899) were categorized into either the propofol (n = 7,439) or sevoflurane (n = 14,460) groups. In the 5,140 propensity-matched patient pairs, there was no significant difference in the proportion of arthrocentesis or debridement [1.3% propofol vs 1.7% sevoflurane; respectively (relative risk, 0.76; 95% CI, 0.55 to 1.04; P = 0.10)] between the groups. The mean (SD) length of stay in the propofol group was significantly longer than in the sevoflurane group [32.5 (18.4) days vs 31.4 (14.4) days, respectively; mean difference, 1.1; 95% CI, 0.5 to 1.8; P < 0.001]. CONCLUSION: Propensity score analysis suggested no significant association between the choice of anesthetic maintenance agent and the occurrence of suspected early-onset periprosthetic joint infection in patients undergoing total knee arthroplasty.

PURPOSE: Despite extensive research on enteral nutrition (EN) for patients in shock, it remains unclear whether this should be postponed in patients with cardiogenic or obstructive shock requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO). In this study, we aimed to compare outcomes of early and delayed EN for patients with cardiogenic or obstructive shock requiring VA-ECMO. METHODS: In this retrospective database study drawing on the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2016, we identified patients with cardiogenic or obstructive shock who had received VA-ECMO for more than 2 days. We allocated the patients to two groups: those who received EN within 2 days (early) or 3 days or more (delayed) after starting VA-ECMO. We then used a marginal structural model to analyze associations between early EN and various outcomes, including in-hospital mortality and 28-day mortality. RESULTS: We identified 1769 eligible patients during the 69-month study period, 220 of whom (12%) received early EN. After using a marginal structural model to adjust for baseline and time-dependent confounders, we found that the early EN group showed significantly lower in-hospital mortality [hazard ratio 0.78, 95% confidence interval (95% CI) 0.62-0.98, P = 0.032] and lower 28-day mortality (hazard ratio 0.74, 95% CI 0.56-0.97, P = 0.031) than the delayed EN group. CONCLUSIONS: According to this retrospective database study, early EN is not associated with harm but rather with lower mortality in patients with cardiogenic or obstructive shock requiring at least 2 days of VA-ECMO.

BACKGROUND: Although public reporting of hospital performance is becoming common, it remains uncertain whether public reporting leads to improvement in clinical outcomes. This study was conducted to evaluate whether enrollment in a quality reporting project is associated with improvement in quality of care for patients with acute myocardial infarction. METHODS: We conducted a quasi-experimental study using hospital census survey and national inpatient database in Japan. Hospitals enrolled in a ministry-led quality reporting project were matched with non-reporting control hospitals by one-to-one propensity score matching using hospital characteristics. Using the inpatient data of acute myocardial infarction patients hospitalized in the matched hospitals during 2011-2013, difference-in-differences analyses were conducted to evaluate the changes in unadjusted and risk-adjusted in-hospital mortality rates over time that are attributable to intervention. RESULTS: Matching between hospitals created a cohort of 30,220 patients with characteristics similar between the 135 reporting and 135 non-reporting hospitals. Overall in-hospital mortality rates were 13.2% in both the reporting and non-reporting hospitals. There was no significant association between hospital enrollment in the quality reporting project and change over time in unadjusted mortality (OR, 0.98; 95% CI, 0.80-1.22). In 28,168 patients eligible for evaluation of risk-adjusted mortality, enrollment was also not associated with change in risk-adjusted mortality (OR, 0.98; 95% CI, 0.81-1.17). CONCLUSIONS: Enrollment in the quality reporting project was not associated with short-term improvement in quality of care for patients with acute myocardial infarction. Additional efforts may be necessary to improve quality of care.

BACKGROUND: There was no established disability predictive measurement for patients with trauma that could be used in administrative claims databases. The aim of the present study was to develop and validate a diagnosis-based disability predictive index for severe physical disability at discharge using the International Classification of Diseases, 10th revision (ICD-10) coding. METHODS: This retrospective observational study used the Diagnosis Procedure Combination database in Japan. Patients who were admitted to hospitals with trauma and discharged alive from 01 April 2010 to 31 March 2015 were included. Pediatric patients under 15 years old were excluded. Data for patients admitted to hospitals from 01 April 2010 to 31 March 2013 was used for development of a disability predictive index (derivation cohort), while data for patients admitted to hospitals from 01 April 2013 to 31 March 2015 was used for the internal validation (validation cohort). The outcome of interest was severe physical disability defined as the Barthel Index score of <60 at discharge. Trauma-related ICD-10 codes were categorized into 36 injury groups with reference to the categorization used in the Global Burden of Diseases study 2013. A multivariable logistic regression analysis was performed for the outcome using the injury groups and patient baseline characteristics including patient age, sex, and Charlson Comorbidity Index (CCI) score in the derivation cohort. A score corresponding to a regression coefficient was assigned to each injury group. The disability predictive index for each patient was defined as the sum of the scores. The predictive performance of the index was validated using the receiver operating characteristic curve analysis in the validation cohort. RESULTS: The derivation cohort included 1,475,158 patients, while the validation cohort included 939,659 patients. Of the 939,659 patients, 235,382 (25.0%) were discharged with severe physical disability. The c-statistics of the disability predictive index was 0.795 (95% confidence interval [CI] 0.794-0.795), while that of a model using the disability predictive index and patient baseline characteristics was 0.856 (95% CI 0.855-0.857). CONCLUSIONS: Severe physical disability at discharge may be well predicted with patient age, sex, CCI score, and the diagnosis-based disability predictive index in patients admitted to hospitals with trauma.

AIM: Tuberculosis screening is recommended for patients with immune-mediated inflammatory diseases (IMIDs) prior to anti-tumor necrosis factor (TNF) therapy. However, adherence to the recommended practice is unknown in the current clinical setting in Japan. METHODS: We used a large-scale health insurance claims database in Japan to conduct a longitudinal observational study. Of more than two million beneficiaries in the database between 2013 and 2014, we enrolled those with IMIDs aged 15-69 years who had initiated anti-TNF therapy. We defined tuberculosis screening primarily as tuberculin skin test and/or interferon-gamma release assay (TST/IGRA) within 2 months before commencing anti-TNF therapy. We analyzed the proportions of the patients who had undergone tuberculosis screening and the associations with primary disease, type of anti-TNF agent, methotrexate prescription prior to anti-TNF therapy, and treatment for latent tuberculosis infection (LTBI). RESULTS: Of 385 patients presumed to have initiated anti-TNF therapy, 252 (66%) had undergone tuberculosis screening by TST/IGRA (22% TST, 56% IGRA, and 12% both TST and IGRA), and 231 (60%) had undergone TST/IGRA and radiography. Patients with psoriasis tended to be more likely to undergo tuberculosis screening than those with other diseases; however, this association was not statistically significant. Treatment for LTBI was provided to 43 (11%) patients; 123 (32%) received neither TST/IGRA nor LTBI treatment. CONCLUSIONS: Tuberculosis screening was often not performed prior to anti-TNF therapy despite the guidelines' recommendations; thus, patients could be put at unnecessary risk of reactivation of tuberculosis.

BACKGROUND: Validation of recorded data is a prerequisite for studies that utilize administrative databases. The present study evaluated the validity of diagnoses and procedure records in the Japanese Diagnosis Procedure Combination (DPC) data, along with laboratory test results in the newly-introduced Standardized Structured Medical Record Information Exchange (SS-MIX) data. METHODS: Between November 2015 and February 2016, we conducted chart reviews of 315 patients hospitalized between April 2014 and March 2015 in four middle-sized acute-care hospitals in Shizuoka, Kochi, Fukuoka, and Saga Prefectures and used them as reference standards. The sensitivity and specificity of DPC data in identifying 16 diseases and 10 common procedures were identified. The accuracy of SS-MIX data for 13 laboratory test results was also examined. RESULTS: The specificity of diagnoses in the DPC data exceeded 96%, while the sensitivity was below 50% for seven diseases and variable across diseases. When limited to primary diagnoses, the sensitivity and specificity were 78.9% and 93.2%, respectively. The sensitivity of procedure records exceeded 90% for six procedures, and the specificity exceeded 90% for nine procedures. Agreement between the SS-MIX data and the chart reviews was above 95% for all 13 items. CONCLUSION: The validity of diagnoses and procedure records in the DPC data and laboratory results in the SS-MIX data was high in general, supporting their use in future studies.

PURPOSE: Little is known about the association between advanced practice nursing and mortality. The aim of this study was to evaluate whether the presence of advanced practice nurses (APN), that is, certified nurse (CN) and certified nurse specialist (CNS) in intensive care, is associated with 30-day mortality for mechanically ventilated critically ill patients. MATERIALS AND METHODS: Using a Japanese national in-patient database, we identified 45,620 patients who were admitted to an intensive care unit (ICU) and received mechanical ventilation within 2 days of hospital admission between 1 April 2014 and 31 March 2015. We assessed the association between the number of CN/CNSs per 10 adult ICU beds and 30-day mortality. RESULTS: We examined 8955 patients in 134 hospitals without CN/CNSs and 36,665 in 284 hospitals with CN/CNSs. Overall, the number of CN/CNSs per 10 adult ICU beds ranged from 0 to 7.5. In the multivariable analysis, the number of CN/CNSs per 10 adult ICU beds was significantly associated with a reduction in 30-day mortality (adjusted odds ratio 0.97; 95% confidence interval, 0.94-1.00; P=0.023). CONCLUSIONS: Our findings show that APNs may play an important role in improving patient outcome in the adult ICU.

INTRODUCTION: To develop and validate a new trauma mortality prediction scoring system based on International Statistical Classification of Diseases (ICD)-10 codes, using a Japanese administrative claims and discharge abstract database. METHODS: This retrospective observational study used the Japanese Diagnosis Procedure Combination database. Injuries were categorised into 33 groups with 5 additional groups based on injury sites and types. A multivariable logistic regression analysis was performed for in-hospital mortality in a derivation cohort after adjusting for the 38 groups, patient's sex, age and Charlson Comorbidity Index score. Each variable was assigned a score that was equal to the value of the regression coefficient. The new severity score was defined as the sum of the scores. The new scoring system was tested in a validation cohort. RESULTS: The mortality rates were 2.4% (9270/393 395) and 2.5% (8778/349 285) in the derivation and validation cohorts, respectively. The area under the receiver operating curve (AUROC) of the new scoring system was 0.887 (95% CI 0.884 to 0.890) in the validation cohort. Subgroup analyses showed that the scoring system retained high predictive performance both for patients <65 years (AUROC 0.934, 95% CI 0.928 to 0.939) and for elderly patients at the age of ≥65 years (AUROC 0.825, 95% CI 0.820 to 0.829). CONCLUSIONS: A new ICD-10-based injury severity scoring system was developed and validated. Further studies are required to validate the scoring system in other databases.

夜間・休日・時間外に外来受診する軽症患者(いわゆるコンビニ受診)により救急医療提供体制に様々な問題が生じている。本研究では、外来レセプトデータと診療録調査により軽症患者識別モデルを開発し、患者数を推計した。国立病院機構に属する2施設の即日入院を除く夜間・休日・時間外受診した外来患者の診療録調査により軽症患者を判定し、レセプトデータを用いてロジスティック回帰分析を行い、3つの識別モデルを作成した。このうち外来レセプトデータのみで推計できる(1)診療区分モデルと(2)診療内容-医療費モデルを使い、国立病院機構に属する200床以上の84病院の即日入院を除く夜間・休日・時間外受診した外来の軽症患者数を推計した。その結果、モデル(1)では43.8%、モデル(2)では42.8%であり、いずれも、200-299床の施設と500床以上の施設で軽症患者割合に有意差を認めた(Dunnett's t p=0.01、p<0.01)。適切な救急医療提供のため必要度に応じた受診支援の検討が必要である。(著者抄録)

PURPOSE: Sivelestat is widely used in Japan for the treatment of acute respiratory distress syndrome caused by pneumonia. Although the efficacy of sivelestat was reported in several Japanese studies in the early 2000 s, a multinational randomized control trial did not support these findings. We therefore conducted the present study to examine the association between the use of sivelestat and mortality in pneumonia patients requiring mechanical ventilation. METHODS: We conducted a retrospective observational study using the Diagnosis Procedure Combination database, a national inpatient database in Japan. We identified pneumonia patients requiring mechanical ventilation who were hospitalized between April 2012 and March 2014. Propensity score matching was performed to compare 7- and 30-day mortality between patients with and without sivelestat use. RESULTS: The eligible patients (n = 16,471) were categorized into the sivelestat (n = 1707) and control (n = 14,764) groups. The unmatched comparison showed significant differences between the sivelestat and control groups in both 7-day mortality (11.0 vs. 7.6%, p < 0.001) and 30-day mortality (29.9 vs. 19.7%, p < 0.001). In the 1516 pairs of propensity-matched patients, there were no significant differences in 7-day mortality (sivelestat vs. CONTROL: 10.2 vs. 10.9%, p = 0.516) and 30-day mortality (sivelestat vs. control 29.0 vs. 29.0%, p = 1.000). CONCLUSIONS: The propensity-matched analyses revealed that the use of sivelestat was not associated with decreased mortality for pneumonia patients requiring mechanical ventilation.

BACKGROUND AND OBJECTIVE: Although oral care may have salutary effects among frail elderly people, access to dental care is often limited in long-term care facilities. In 2009, the Japanese long-term care insurance system introduced an additional reimbursement scheme for enhanced oral care supervised by dentists in nursing facilities. The aim of this study was to examine whether enhanced oral care provided by trained nursing facility staff members is sufficient to improve health outcomes among nursing facility residents. DESIGN, SETTING, AND PARTICIPANTS: This was a quasi-experimental study using a nationwide long-term care database. Using facility-level propensity score matching, we identified 170,874 residents in 742 facilities that provided enhanced oral care and 167,546 residents in 742 control facilities that provided only standard care from 2009 to 2012. We used a resident-level difference-in-differences approach to analyze the impact of enhanced oral care on health outcomes among nursing facility residents. RESULTS: After controlling for resident characteristics and background time trends, no significant differences were found between residents admitted to the facilities with and without enhanced oral care in the incidence of critical illness, transfer to a hospital, mortality, or costs. Yearly change in the odds of discharge to home was significantly increased for residents with enhanced oral care (odds ratio = 1.07; 95% confidence interval: 1.02-1.12; P = .008). CONCLUSION: The results suggest that enhanced oral care provided by trained nursing facility staff members may improve the general condition of elderly residents in nursing facilities and promote their discharge to home.

Objective: Studies on the outcomes of lower limb amputation have been limited by the use of selected study populations and small sample sizes. Although reamputation is an important outcome following lower limb amputation, the risk factors for reamputation remain to be elucidated. The present study was performed to identify risk factors for in-hospital death and reamputation following lower limb amputation. Methods: Using a national inpatient database in Japan, we identified 13,774 patients who underwent lower limb amputation. We examined the patients' backgrounds and employed a multivariable logistic regression analysis to identify factors associated with in-hospital death or reamputation. Results: The average age of the 13,774 patients was 72.4 years, and 63.1% (n=8694) were male. The overall in-hospital mortality rate was 10.8% (1481/13,774). The reamputation rate was 10.1% (782/7779) for patients who initially underwent foot or transtibial amputation (18.2% [391/2148] for foot amputations and 6.9% [391/5631] for transtibial amputations). Multivariable logistic regression analysis revealed higher age, male sex, peripheral vascular disease, use of insulin, hemodialysis, and higher numbers of comorbidities as significant risk factors for reamputation or in-hospital death. Use of hemodialysis was the strongest risk factor (odds ratio, 2.10; 95% confidence interval, 1.87-2.35). Conclusions: The in-hospital mortality and reamputation rates following lower limb amputation were considerably high, reflecting the severely ill conditions of patients with advanced chronic diseases. Risk factors for in-hospital death and reamputation following lower limb amputation were identified. These should aid surgeons in determining a patient's risk of a poor outcome and deciding on the level of amputation.

BACKGROUND: Diagnoses recorded in administrative databases have limited utility for accurate identification of severe sepsis and disseminated intravascular coagulation (DIC). We evaluated the performance of alternative identification methods that use procedure records. METHODS: We obtained data for adult patients admitted to intensive care units in three hospitals during a 1-year period. Severe sepsis and DIC were identified by three means: laboratory data, diagnoses, and procedures. Using laboratory data as a reference, the sensitivity and specificity of procedure-based methods and diagnosis-based methods were compared. RESULTS: Of 595 intensive care unit admissions, 212 (35.6%) and 81 (13.6%) were identified as severe sepsis and DIC, respectively, using laboratory data. The sensitivity of procedure-based methods for identifying severe sepsis was 64.2%, and the specificity was 65.3%. Two diagnosis-based methods -the Angus and Martin algorithms- exhibited sensitivities of 21.7% and 14.6% and specificities of 98.7% and 99.5%, respectively, for severe sepsis. For DIC, the sensitivity of procedure-based methods was 55.6%, and the specificity was 67.1%, and the sensitivity and specificity of diagnosis-based methods were 35.8% and 98.2%, respectively. CONCLUSIONS: Procedure-based methods were more sensitive and less specific than diagnosis-based methods in identifying severe sepsis and DIC. Procedure records could improve disease identification in administrative databases.

過量服薬により救命救急センターへ入院した患者への退院前の精神科介入と、過量服薬による再入院の減少の関連を明らかにすることを目的に、Diagnosis Procedure Combination(DPC)データベース(DPCデータ調査研究班)を用い、2010年7月1日〜2013年3月1日(33ヵ月間)にDPC参加病院(368病院)を退院した薬物中毒(ICD-10コード:T360-509)と診断された患者29564名のデータを検討した。傾向マッチングにより得られた患者(15876名)の精神科介入群7938名と対照群7938名を比較検討した結果、介入群の再入院患者は582名(7.3%)、対照群の再入院患者は722名(9.1%)で両群に有意差が認められ、精神科医の介入が再入院の減少につながっていることが確認できた。

OBJECTIVES: To compare mortality between de-escalation and continued empirical treatment in patients with community-acquired pneumonia. METHODS: Using a nationwide administrative database, we identified adult patients with community-acquired pneumonia caused by Streptococcus pneumoniae, other streptococci, Haemophilus influenzae, Klebsiella pneumoniae, or Escherichia coli (n = 10,231) or of unknown etiology (n = 8247), discharged between July 2010 and March 2013. De-escalation was determined by the spectrum and number of antimicrobials at day 4. We used propensity score matching to obtain 489 pairs of de-escalation and continuation groups among pathogen-identified patients and 278 pairs among culture-negative patients to compare mortalities. RESULTS: In the pathogen-identified patients, de-escalation was noninferior to continuation in 15-day mortality [5.3% in de-escalation versus 4.3% in continuation, a difference of 1.0% (95% confidence interval, -1.7% to 3.7%)] and in-hospital mortality [8.0% in de-escalation versus 8.8% in continuation, a difference of -0.8% (95% confidence interval, -4.3% to 2.7%)]. In the culture-negative cases, de-escalation was noninferior to continuation in terms of 15-day mortality but not in terms of in-hospital mortality. CONCLUSIONS: Among patients with community-acquired pneumonia of specific etiology, de-escalation was noninferior to continuation of empirical treatment, suggesting that de-escalation is a safe strategy and supporting current recommendations. Safety of de-escalation in culture-negative cases is questionable.

[背景]医療機関の総合的機能を評価するストラクチャー指標としてDPC群分類や病床数などが用いられてきたが,病院機能を細部にわたって評価しているとはいえない.本研究では,個々の高度な医療技術・サービスを評点化し統合するtechnology indexを用いて機能を評価し,従来のストラクチャー指標と比較した.[方法]2014年度の病床機能報告データからtechnology indexを算出し,technology indexとDPC群分類および病床数との比較を行った.[結果]Technology indexは最小値0,最大値9.60,中央値0.65となった.Technology index中央値は,DPCI群7.66,II群6.67,III群2.97,非DPC群0.14となり,4群間で有意差を認めた(p<0.001).一般病床のみの施設では,どの病床数群にもtechnology indexの高い施設が存在した.療養病床のみの施設においても,technology indexの高い施設は存在した.[考察]Technology indexはDPC群分類と有意な相関を認めたものの,非DPC群にも高いtechnology indexを有する施設が認められた.また,療養施設にも高いtechnology indexが認められ,病院機能分化が不十分である現状も示唆された.(著者抄録)

BACKGROUND AND OBJECTIVE: Intravenous magnesium sulfate is used as adjunctive therapy for severe asthma exacerbations. However, previous randomized controlled trials of the administration of intravenous magnesium sulfate for asthma exacerbations have shown mixed results, and no study has evaluated its effect on mortality in patients with life-threatening asthma. The objective of this study was to investigate the association between intravenous magnesium sulfate administration and mortality in patients with severe asthma. METHODS: Patients with severe asthma requiring intravenous corticosteroids and oxygenation were selected using the Japanese Diagnosis Procedure Combination inpatient database. One-to-one propensity score matching was performed between patients having received or not intravenous magnesium sulfate. Primary outcomes were 7-, 14- and 28-day mortalities. Secondary outcomes were total dose of intravenous corticosteroids during hospitalization, duration of mechanical ventilation and length of stay. RESULTS: Among 14,122 eligible patients, 619 received intravenous magnesium sulfate. Propensity score matching created a matched cohort of 599 pairs with and without intravenous magnesium sulfate. There were no significant differences between patients with and without intravenous magnesium sulfate in terms of 28-day mortality (1.3% vs 1.8%, P = 0.488), median total dose of intravenous corticosteroids (2400 mg vs 2400 mg, P = 0.580), median duration of mechanical ventilation (1 day vs 1 day, P = 0.118) and median length of stay (16 days vs 13 days, P = 0.640). CONCLUSION: This study found no significant benefit of intravenous magnesium sulfate use in terms of mortality in patients with severe acute asthma.

BACKGROUND: Repeated drug overdose is a major risk factor for suicide. Data are lacking on the effect of psychiatric intervention on preventing repeated drug overdose. AIMS: To investigate whether psychiatric intervention was associated with reduced readmission to emergency centres due to drug overdose. METHOD: Using a Japanese national in-patient database, we identified patients who were first admitted to emergency centres for drug overdose in 2010-2012. We used propensity score matching for patient and hospital factors to compare readmission rates between intervention (patients undergoing psychosocial assessment) and unexposed groups. RESULTS: Of 29 564 eligible patients, 13 035 underwent psychiatric intervention. In the propensity-matched 7938 pairs, 1304 patients were readmitted because of drug overdose. Readmission rate was lower in the intervention than in the unexposed group (7.3% v. 9.1% respectively, P<0.001). CONCLUSIONS: Psychiatric intervention was associated with reduced readmission in patients who had taken a drug overdose. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

OBJECTIVES: Comorbidity measures are widely used in administrative databases to predict mortality. The Japanese Diagnosis Procedure Combination database is unique in that secondary diagnoses are recorded into subcategories, and procedures are precisely recorded. We investigated the influence of these features on the performance of mortality prediction models. STUDY DESIGN AND SETTING: We obtained data of adult patients with main diagnosis of acute myocardial infarction, congestive heart failure, acute cerebrovascular disease, gastrointestinal hemorrhage, pneumonia, or septicemia during a 1-year period. Multiple models were constructed representing different subcategories from which Charlson and Elixhauser comorbidities were extracted. Prevalence of comorbidities and C statistics of logistic regression models predicting in-hospital mortality was compared. Associations between four procedures (computed tomography, oxygen administration, urinary catheter, and vasopressors) and mortality were also evaluated. RESULTS: C statistics of the model using all secondary diagnoses (Charlson: 0.717; Elixhauser: 0.762) were greater than those using a limited subcategory to strictly specify comorbidities (Charlson: 0.708; Elixhauser: 0.744). However, misidentification of complications and main diagnoses as comorbidities was observed in the all-diagnosis model. The four procedures were associated with mortality. CONCLUSION: Subcategorized diagnoses allowed correct identification of comorbidities and procedures predicted mortality. Incorporation of these two features should be considered for other administrative databases.

BACKGROUND: Risk adjustment is important in studies using administrative databases. Although utilization of diagnostic and therapeutic procedures can represent patient severity, the usability of procedure records in risk adjustment is not well-documented. Therefore, we aimed to develop and validate a severity index calculable from procedure records. METHODS: Using the Japanese nationwide Diagnosis Procedure Combination database of acute-care hospitals, we identified patients discharged between 1 April 2012 and 31 March 2013 with an admission-precipitating diagnosis of acute myocardial infarction, congestive heart failure, acute cerebrovascular disease, gastrointestinal hemorrhage, pneumonia, or septicemia. Subjects were randomly assigned to the derivation cohort or the validation cohort. In the derivation cohort, we used multivariable logistic regression analysis to identify procedures performed on admission day which were significantly associated with in-hospital death, and a point corresponding to regression coefficient was assigned to each procedure. An index was then calculated in the validation cohort as sum of points for performed procedures, and performance of mortality-predicting model using the index and other patient characteristics was evaluated. RESULTS: Of the 539 385 hospitalizations included, 270 054 and 269 331 were assigned to the derivation and validation cohorts, respectively. Nineteen significant procedures were identified from the derivation cohort with points ranging from -3 to 23, producing a severity index with possible range of -13 to 69. In the validation cohort, c-statistic of mortality-predicting model was 0.767 (95 % confidence interval: 0.764-0.770). The ω-statistic representing contribution of the index relative to other variables was 1.09 (95 % confidence interval: 1.03-1.17). CONCLUSIONS: Procedure-based severity index predicted mortality well, suggesting that procedure records in administrative database are useful for risk adjustment.

SETTING: Although standardised multidrug treatments exist, mortality among hospitalised tuberculosis (TB) patients is high. OBJECTI VE: To characterise TB patients requiring acute hospital care and identify factors associated with in-hospital mortality. DESIGN: Using a Japanese national database of acutecare hospitals, we identified patients with sputum smearpositive pulmonary TB who were discharged (both deceased and alive) between July 2010 and March 2013. Demographic characteristics, comorbidity, procedures and treatments were examined. We performed a multivariable logistic regression analysis to identify risk factors for in-hospital mortality. RESULTS: Of 877 treated patients (566 males, mean age 74.5 years) identified, 152 (17.3%) died. A standard four-drug regimen of isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and pyrazinamide was given to 279 (31.8%) patients, and INH, RMP and EMB to 335 (38.2%) patients. Multivariable analysis showed that the three-drug regimen was significantly associated with higher rates of in-hospital mortality (OR 1.87, 95%CI 1.07-3.27, P = 0.028). Other factors associated with in-hospital death were age, male sex, smoking habit, emergency admission, dementia and severe respiratory condition. CONCLUSION: The risk factors for in-hospital death identified include the use of the three-drug regimen. Treatment choice could influence the outcome of hospitalised TB patients.