Impact of the hospital volume and setting on postoperative complications of surgery for gastroenterological cancers in a regional area of Western Japan.

PURPOSE: A research subgroup was established by the Japanese Society of Gastroenterological Surgery to improve the health care quality in the Chushikoku area of Western Japan. METHODS: The records of four surgical procedures were extracted from the Japanese National Clinical Database and analyzed retrospectively to establish the association between hospital characteristics, defined using a combination of hospital case-volume and patients' hospital travel distance, and the incidences of perioperative complications of ≥ Grade 3 of the Clavien-Dindo classification after gastroenterological surgery. RESULTS: This study analyzed 11,515 cases of distal gastrectomy for gastric cancer, 4,705 cases of total gastrectomy for gastric cancer, 4,996 cases of right hemicolectomy for colon cancer, and 5,243 cases of lower anterior resection for rectal cancer, with composite outcome incidences of 5.6%, 10.2%, 5.5%, and 10.7%, respectively. After adjusting for patient characteristics and surgical procedures, no association was identified between the hospital category and surgical outcomes. CONCLUSION: The findings of our study of the Chushikoku region did not provide positive support for the consolidation and centralization of hospitals, based solely on hospital case volume. Our grouping was unique in that we included patient travel distance in the analysis, but further investigations from other perspectives are needed.

Cost Analysis of Screening for IgA Nephropathy Using Novel Biomarkers.

OBJECTIVES: IgA nephropathy (IgAN) is the most common primary chronic glomerulonephritis and a major cause of end-stage kidney disease worldwide. Novel biomarkers, including the aberrantly glycosylated IgA1 and glycan-specific antibodies, could be useful in the diagnosis of IgAN. The aim of this study was to assess the cost analysis of IgAN screening using novel biomarkers in addition to the conventional screening compared with conventional screening alone. METHODS: To estimate the medical expense of each strategy related to renal disease for 40 years, we developed an analytical decision model. The decision tree started at "40 years of age with first-time hematuria." It simulated 2 clinical strategies: IgAN screening using the novel biomarkers (group N) and conventional screening (group C). The analysis results were presented as medical expenses from a societal perspective. Discounting was not conducted. RESULTS: The expected medical expense per person for 40 years was ¥31.2 million (~$291 000) in group N and ¥33.4 million (~$312 000) in group C; hence, expense in group N was lower by ¥2.2 million (~$21 000). In group N, the expected value of IgAN increased by 5.67% points (N 48.44%, C 42.77%) and that of dialysis introduction decreased by 0.85% points (N 19.06%, C 19.91%). In the sensitivity analysis, expenses could be reduced in almost all cases except when renal biopsy using conventional screening was performed at the rate of 73% or higher. CONCLUSION: Screening for IgAN using novel biomarkers would reduce renal disease-related expenses.

Epidemiology of mechanically ventilated patients treated in ICU and non-ICU settings in Japan: a retrospective database study.

BACKGROUND: In most countries, patients receiving mechanical ventilation (MV) are treated in intensive care units (ICUs). However, in some countries, including Japan, many patients on MV are not treated in ICUs. There are insufficient epidemiological data on these patients. Here, we sought to describe the epidemiology of patients on MV in Japan by comparing and contrasting patients on MV treated in ICUs and in non-ICU settings. A preliminary comparison of patient outcomes between ICU and non-ICU patients was a secondary objective. METHODS: Data on adult patients receiving MV for at least 3 days in ICUs or non-ICU settings from April 2010 through March 2012 were obtained from the Quality Indicator/Improvement Project, a voluntary data-administration project covering more than 400 acute-care hospitals in Japan. We excluded patients with cancer-related diagnoses. Patient demographic data and the critical care provided were compared between groups. RESULTS: Over the study period, 17,775 patients on MV were treated only in non-ICU settings, whereas 20,516 patients were treated at least once in ICUs (46.4% vs. 53.6%). Average age was higher in non-ICU patients than in ICU patients (72.8 vs. 70.2, P < 0.001). Mean number of ventilation days was greater in non-ICU patients (11.7 vs. 9.5, P < 0.001). Hospital mortality was higher in non-ICU patients (41.4% vs. 38.8%, P < 0.001). Standard critical care (e.g., arterial line placement, enteral nutrition, and stress-ulcer prevention) was provided significantly less often in non-ICU patients. Multivariate analysis showed that ICU admission significantly decreased hospital mortality (adjusted odds ratio 0.713, 95% CI 0.676 to 0.753). CONCLUSIONS: A large proportion of Japanese patients on MV were treated in non-ICU settings. Analysis of administrative data indicated preliminarily that hospital mortality rates in these patients were higher in non-ICU settings than in ICUs. Prospective analyses comparing non-ICU and ICU patients on MV by severity scoring are needed.

Differences between determinants of in-hospital mortality and hospitalisation costs for patients with acute heart failure: a nationwide observational study from Japan.

OBJECTIVES: Although current case-mix classifications in prospective payment systems were developed to estimate patient resource usage, whether these classifications reflect clinical outcomes remains unknown. The efficient management of acute heart failure (AHF) with high mortality is becoming more important in many countries as its prevalence and associated costs are rapidly increasing. Here, we investigate the determinants of in-hospital mortality and hospitalisation costs to clarify the impact of severity factors on these outcomes in patients with AHF, and examine the level of agreement between the predicted values of mortality and costs. DESIGN: Cross-sectional observational study. SETTING AND PARTICIPANTS: A total of 19 926 patients with AHF from 261 acute care hospitals in Japan were analysed using administrative claims data. MAIN OUTCOME MEASURES: Multivariable logistic regression analysis and linear regression analysis were performed to examine the determinants of in-hospital mortality and hospitalisation costs, respectively. The independent variables were grouped into patient condition on admission, postadmission procedures indicating disease severity (eg, intra-aortic balloon pumping) and other high-cost procedures (eg, single-photon emission CT). These groups of independent variables were cumulatively added to the models, and their effects on the models' abilities to predict the respective outcomes were examined. The level of agreement between the quartiles of predicted mortality and predicted costs was analysed using Cohen's κ coefficient. RESULTS: In-hospital mortality was associated with patient's condition on admission and severity-indicating procedures (C-statistics 0.870), whereas hospitalisation costs were associated with severity-indicating procedures and high-cost procedures (R2 0.32). There were substantial differences in determinants between the outcomes. In addition, there was no consistent relationship observed (κ=0.016, p<0.0001) between the quartiles of in-hospital mortality and hospitalisation costs. CONCLUSIONS: The determinants of mortality and costs for hospitalised patients with AHF were generally different. Our results indicate that the same case-mix classifications should not be used to predict both these outcomes.

Asymptomatic C-reactive protein elevation in neutropenic children.

BACKGROUND: Febrile neutropenia (FN) can be a life-threatening complication in children with malignancies. There is no standardized preventive treatment for childhood FN, and information on C-reactive protein (CRP) elevation in afebrile patients with neutropenia (CEAN) is limited. The aim of this study was therefore to identify the association between CEAN and FN onset, and evaluate the efficacy of broad-spectrum antibiotics for FN prophylaxis. METHODS: We retrospectively reviewed the medical records of 22 consecutive pediatric patients with hematologic malignancies (acute myeloid leukemia, n = 2; acute lymphoid leukemia, n = 20) admitted to the present institution between 2006 and 2011. CEAN was defined as CRP elevation ≥0.05 mg/dL between the two most recent blood tests with no fever. We identified CEAN before FN onset, and assessed the efficacy of broad-spectrum antibiotics for FN prevention in CEAN. FN incidence within 48 h after CEAN detection was compared between prophylactic and non-prophylactic episodes. RESULTS: CEAN was observed before FN onset in 20 (55.6%), of 36 FN episodes. Among the 95 analyzed CEAN episodes, broad-spectrum antibiotics had been used for 30 episodes (prophylactic episodes), whereas these antibiotics had not been used in 60 episodes (non-prophylactic episodes). Prophylactic episodes had a significantly lower FN incidence than non-prophylactic episodes (6.7% and 31%, respectively, P < 0.01) within 48 h after CEAN detection. Bacteremia was observed in three non-prophylactic episodes. CONCLUSION: Patients with CEAN are at higher risk of FN, and physicians may consider the use of broad-spectrum antibiotics to prevent FN development.

The relationship between sedative drug utilization and outcomes in critically ill patients undergoing mechanical ventilation.

OBJECTIVES: The objectives of this study were to describe current sedative drug utilization patterns in critically ill patients undergoing mechanical ventilation (MV) in intensive care units (ICUs) in Japanese hospitals and to elucidate the relationship of these utilization patterns with patient clinical outcomes. METHOD: Analysis of hospital claims data derived from the Quality Indicator/Improvement Project identified 12,395 critically ill adult patients who had undergone MV while hospitalized in the ICUs of 114 Japanese hospitals and had been discharged between April 2008 and March 2010. Descriptive statistics were calculated for the daily utilization of sedative drugs, opioids, and muscle relaxants in this patient sample, and the relationship between drug utilization and patient outcomes using Cox proportional hazards analysis were examined. RESULTS: Of the 12,395 patients included in the analysis, 7300 (58.9 %), 580 (4.7 %), and 671 (5.4 %) received sedative drugs, opioids, and muscle relaxants, respectively, for ≥2 days after intubation. Compared to the other patient groups, there was a higher proportion of males in the group given sedative drugs and the patients were significantly younger (P < 0.001). Propofol was the most frequently used sedative drug, followed by benzodiazepines, barbiturates, and dexmedetomidine. The mortality rate was lower and ventilator weaning was earlier among patients who received only propofol than among those who received only benzodiazepines. Muscle relaxants were associated with increased duration of MV. CONCLUSIONS: This is the first study based on a large-scale analysis in Japan to elucidate sedative drug utilization patterns and their relationship with outcomes in critically ill patients. The most commonly used sedative was propofol, which was associated with favorable patient outcomes. Further prospective research must be conducted to discern effective sedative drug utilization.

Regional variations in in-hospital mortality, care processes, and spending in acute ischemic stroke patients in Japan.

BACKGROUND: Little is known about the regional variations in ischemic stroke care in Japan. This study investigates the regional variations and associations among outcomes, care processes, spending, and physician workforce availability in acute ischemic stroke care. METHODS: Using administrative claims data from National Claims Database, we identified National Health Insurance beneficiaries aged 65 years and older and Long Life Medical Care System beneficiaries from 9 prefectures who had been hospitalized for acute ischemic stroke between April 2010 and March 2012. Patients were grouped according to their subprefectural regions of residence known as secondary medical areas (SMAs). Performances in 8 outcome and process of care measures were analyzed in each SMA. Multilevel regression models with 2 levels (patient and regional) were used to analyze age- and sex-adjusted in-hospital mortality, hospitalization spending, and tissue plasminogen activator (tPA) utilization rate. The associations between regional supply of physicians for stroke care and the various quality measures were investigated. RESULTS: We analyzed 49,440 acute ischemic stroke patients. The regional variations among SMAs in in-hospital mortality, spending, and tPA utilization were 3.2-, 1.7-, and 5.9-fold, respectively. Higher physician supply was significantly associated with lower in-hospital mortality and higher spending. Additionally, spending had a significantly negative correlation with regional continuity of care planning rate but a significantly positive correlation with rehabilitation rate. CONCLUSIONS: The study revealed substantial regional variations in Japanese ischemic stroke care. Improving the allocative efficiency of physicians and establishing continuity of care networks may be useful in mitigating regional disparities and reconstructing the stroke care system.

Development of a risk-adjusted in-hospital mortality prediction model for community-acquired pneumonia: a retrospective analysis using a Japanese administrative database.

BACKGROUND: Community-acquired pneumonia (CAP) is a common cause of patient hospitalization and death, and its burden on the healthcare system is increasing in aging societies. Here, we develop and internally validate risk-adjustment models and scoring systems for predicting mortality in CAP patients to enable more precise measurements of hospital performance. METHODS: Using a multicenter administrative claims database, we analyzed 35,297 patients hospitalized for CAP who had been discharged between April 1, 2012 and September 30, 2013 from 303 acute care hospitals in Japan. We developed hierarchical logistic regression models to analyze predictors of in-hospital mortality, and validated the models using the bootstrap method. Discrimination of the models was assessed using c-statistics. Additionally, we developed scoring systems based on predictors identified in the regression models. RESULTS: The 30-day in-hospital mortality rate was 5.8%. Predictors of in-hospital mortality included advanced age, high blood urea nitrogen level or dehydration, orientation disturbance, respiratory failure, low blood pressure, high C-reactive protein levels or high degree of pneumonic infiltration, cancer, and use of mechanical ventilation or vasopressors. Our models showed high levels of discrimination for mortality prediction, with a c-statistic of 0.89 (95% confidence interval: 0.89-0.90) in the bootstrap-corrected model. The scoring system based on 8 selected variables also showed good discrimination, with a c-statistic of 0.87 (95% confidence interval: 0.86-0.88). CONCLUSIONS: Our mortality prediction models using administrative data showed good discriminatory power in CAP patients. These risk-adjustment models may support improvements in quality of care through accurate hospital evaluations and inter-hospital comparisons.

Trends in hospital performance in acute myocardial infarction care: a retrospective longitudinal study in Japan.

OBJECTIVE: To elucidate the hospital characteristics associated with hospital performance and time trends in acute myocardial infarction (AMI) care using multilevel multivariable analysis of longitudinal data. DESIGN: Retrospective longitudinal study. SETTING: One hundred and fourteen hospitals in Japan. PARTICIPANTS: A total of 26 210 AMI patients admitted between 2008 and 2011. MAIN OUTCOME MEASURE: A composite score was calculated from five AMI process measures. Hospital performances and time trends were then investigated based on this composite score. Using generalized linear mixed models with random intercepts (indicating hospital baseline performance) and random slopes (indicating trends in improvement), we analyzed the associations between performance and the following factors: hospital ownership, AMI case volume, number of cardiovascular specialists per AMI patient and participation in a public disclosure program. RESULTS: Hospitals that demonstrated high performance in the composite score were significantly associated with high AMI case volume, municipal ownership and agreement to named disclosure of hospital performance. The following factors were significantly associated with time trends of improvement in performance: public and private ownership, AMI case volume and number of cardiovascular specialists per AMI patient. In addition, higher performances were associated with diminished improvement. CONCLUSIONS: Time trends in improvement were related to baseline performance and several hospital characteristics. Furthermore, hospitals that had agreed to named disclosure of performance were more likely to have better quality of care at the initial point of public disclosure. These findings can inform the decision-making process for quality improvement, and allow a greater understanding and interpretation of disclosed performances in quality measures.

Survival analyses of postoperative lung cancer patients: an investigation using Japanese administrative data.

Long-term survival rates of cancer patients represent important information for policymakers and providers, but analyses from voluntary cancer registries in Japan may not reflect the overall situation. In 2003, the Diagnosis Procedure Combination Per-Diem Payment System (DPC/PDPS) for hospital reimbursement was introduced in Japan; more than half of Japan's acute care beds are currently covered under this system. Administrative data produced under the DPC system include claims data and clinical summaries for each admission. Due to the large amount of data spanning multiple institutions, this database may have applications in providing a more general and inclusive overview of healthcare. Here, we investigate the use of administrative data for analyses of long-term survival in cancer patients. We analyzed postoperative survival in 7,064 patients with primary non-small cell lung cancer admitted to 102 hospitals between April 2008 and March 2013 using DPC data. Survival was defined at the last date of examination or discharge within the study period, and the event was mortality during the same period. Overall survival rates for different cancer stages were calculated using the Kaplan-Meier method. Additionally, survival rates of cancer patients at clinical stage IA were compared between low- and high-volume hospitals using the Log-rank test. Postoperative 5-year survival for patients at stage IA was 85.8% (95% CI = 78.6%-93.0%). High-volume hospitals had higher survival rates than hospitals with lower volume. Our findings using large-scale administrative data were similar to previous clinical registry reports, showing potential applications as a new method in analyzing up-to-date healthcare information.

Factors associated with the administration of tissue plasminogen activator for acute ischemic stroke.

BACKGROUND: The use of intravenous tissue plasminogen activator (t-PA) can be an effective treatment for acute ischemic stroke if administered promptly. Despite its clinical effectiveness, overall use in Japan remains low, and regional variations have been reported. Factors such as ambulance utilization and geographical distance from patients' residences to hospitals may influence t-PA administration rates. The aim of this study is to identify factors associated with the administration of t-PA for acute ischemic stroke while adjusting for casemix using a large-scale administrative database in Japan. METHODS: We analyzed acute ischemic stroke patients admitted to acute care hospitals between July 2010 and March 2011 using a nationwide database. A logistic regression model was used to analyze the factors influencing t-PA administration. Candidate factors included patient gender, age, stroke severity, direct distance between each patient's residence and admitting hospital, and ambulance utilization. RESULTS: Of the 10,615 ischemic stroke patients from 89 hospitals analyzed, 557 (5.2%) received t-PA treatment. Patients aged 75 years and older were found to be associated with decreased t-PA administration. In contrast, severe stroke and ambulance utilization were associated with increased t-PA administration. Distance was not significantly associated with the use of t-PA. CONCLUSIONS: Our findings suggest that ambulance utilization is an important factor for improving the likelihood of t-PA administration in patients with stroke and may underline a need for educational programs to the general public that promote the use of ambulances for suspected stroke patients.

The relationship between the number of cardiologists and clinical practice patterns in acute heart failure: a cross-sectional observational study.

OBJECTIVES: Despite the increasing burden of acute heart failure (AHF) on healthcare systems, the association between centralised cardiovascular specialist care and the quality of AHF care remains unknown. We examine the relationship between the number of cardiologists per hospital and hospital practice variations. DESIGN, SETTING AND PARTICIPANTS: In a retrospective observational study, we analysed 38,668 patients with AHF admitted to 546 Japanese acute care hospitals between 2010 and 2011 using the Diagnosis Procedure Combination administrative claims database. Sample hospitals were categorised into four groups according to the number of cardiologists per facility (none, 1-4, 5-9 and ≥10). To confirm the capability of administrative data to identify patients with AHF, the ≥10 cardiologists group was compared with two recent clinical registries in Japan. MAIN OUTCOME MEASURES: Using multivariable logistic regression models, patient risk-adjusted in-hospital mortality rates and age-sex-adjusted ORs of various AHF therapies were calculated and compared among four hospital groups. RESULTS: The ≥10 cardiologists group of hospitals from the administrative database had similar major underlying disease incidence and therapeutic practices to those of the clinical registry hospitals. Age-adjusted and sex-adjusted ORs of various AHF therapies in the four hospital groups revealed wide practice variations associated with the number of cardiologists. Adjusted in-hospital mortality demonstrated a negative association with the number of cardiologists. In addition, the different hospital-level distribution patterns of specific therapeutic practices illustrated the diffusion process of therapies across facilities. CONCLUSIONS: Wide practice variations in AHF care were associated with the number of cardiologists per facility, indicating a possible relationship between the quality of AHF care and manpower resources. The provision of recommended therapies increased together with the number of cardiologists.

Association of geographical factors with administration of tissue plasminogen activator for acute ischemic stroke.

BACKGROUND: Intravenous tissue plasminogen activator (tPA) is an effective treatment for acute ischemic stroke if administered within a few hours of stroke onset. Because of this time restriction, tPA administration remains infrequent. Ambulance use is an effective strategy for increasing tPA administration but may be influenced by geographical factors. The objectives of this study are to investigate the relationship between tPA administration and ambulance use and to examine how patient travel distance and population density affect tPA utilization. METHODS AND RESULTS: We analyzed administrative claims data from 114,194 acute ischemic stroke cases admitted to 603 hospitals between July 2010 and March 2012. Mixed-effects logistic regression models of patients nested within hospitals with a random intercept were generated to analyze possible predictive factors (including patient characteristics, ambulance use, and driving time from home to hospital) of tPA administration for different population density categories to investigate differences in these factors in various regional backgrounds. Approximately 5.1% (5797/114,194) of patients received tPA. The composition of baseline characteristics varied among the population density categories, but adjustment for covariates resulted in all factors having similar associations with tPA administration in every category. The administration of tPA was associated with patient age and severity of stroke symptoms, but driving time showed no association. Ambulance use was significantly associated with tPA administration even after adjustment for covariates. CONCLUSION: The association between ambulance use and tPA administration suggests the importance of calling an ambulance for suspected stroke. Promoting ambulance use for acute ischemic stroke patients may increase tPA use.

Decentralization and centralization of healthcare resources: investigating the associations of hospital competition and number of cardiologists per hospital with mortality and resource utilization in Japan.

OBJECTIVE: To investigate the associations of hospital competition and number of cardiologists per hospital (indicating the decentralization and centralization of healthcare resources, respectively) with 30-day in-hospital mortality, healthcare spending, and length of stay (LOS) among patients with acute myocardial infarction (AMI) in Japan. METHODS: We collected data from 23,197 AMI patients admitted to 172 hospitals between 2008 and 2011. Hospital competition and number of cardiologists per hospital were analyzed as exposure variables in multilevel regression models for in-hospital mortality, healthcare spending, and LOS. Other covariates included patient, hospital, and regional variables; as well as the use of percutaneous coronary intervention (PCI). RESULTS: Hospitals in competitive regions and hospitals with a higher number of cardiologists were both associated lower in-hospital mortality. Additionally, hospitals in competition regions were also associated with longer LOS durations, whereas hospitals with more cardiologists had higher spending. The use of PCI was also associated with reduced mortality, increased spending and increased LOS. CONCLUSIONS: Centralization of cardiologists at the hospital level and decentralization of acute hospitals at the regional level may be contributing factors for improving the quality of care in Japan. Policymakers need to strike a balance between these two approaches to improve healthcare provision and quality.

Quality of care and in-hospital resource use in acute myocardial infarction: evidence from Japan.

OBJECTIVES: To determine the association between quality of care in process and outcome measures and in-hospital resource use among patients admitted for acute myocardial infarction (AMI) in Japan. METHODS: We analyzed 23,512 AMI patients across 150 hospitals in Japan between April 2008 and March 2011. The exposure measure was inpatient hospital resource use, which was calculated from the sum of all hospital fees for healthcare services provided to AMI patients. Hospitals were then categorized into quartiles based on a risk-adjusted in-hospital resource use index. Quality of care was assessed using three process measures (in-hospital prescription of aspirin, ß-blockers, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) and two outcome measures (7-day and 30-day in-hospital mortality). Process and outcome measures were analyzed with multilevel logistic regression models that adjusted for patient and hospital characteristics. RESULTS: No significant differences in process measures were observed across the quartiles of in-hospital resource use. In contrast, hospitals with the lowest resource use were significantly associated with poorer outcomes (7-day in-hospital mortality OR: 1.851 [95% CI 1.327-2.582]; 30-day in-hospital mortality OR: 1.706 [95% CI 1.259-2.312]) than hospitals with higher resource use. CONCLUSION: Poorer quality of care in outcome measures was significantly associated with lower resource utilization among AMI patients in Japanese hospitals, but process measures did not show similar associations.

An in-hospital mortality equation for mechanically ventilated patients in intensive care units.

OBJECTIVE: To develop an equation model of in-hospital mortality for mechanically ventilated patients in adult intensive care using administrative data for the purpose of retrospective performance comparison among intensive care units (ICUs). DESIGN: Two models were developed using the split-half method, in which one test dataset and two validation datasets were used to develop and validate the prediction model, respectively. Nine candidate variables (demographics: age; gender; clinical factors hospital admission course; primary diagnosis; reason for ICU entry; Charlson score; number of organ failures; procedures and therapies administered at any time during ICU admission: renal replacement therapy; pressors/vasoconstrictors) were used for developing the equation model. SETTING: In acute-care teaching hospitals in Japan: 282 ICUs in 2008, 310 ICUs in 2009, and 364 ICUs in 2010. PARTICIPANTS: Mechanically ventilated adult patients discharged from an ICU from July 1 to December 31 in 2008, 2009, and 2010. MAIN OUTCOME MEASURES: The test dataset consisted of 5,807 patients in 2008, and the validation datasets consisted of 10,610 patients in 2009 and 7,576 patients in 2010. Two models were developed: Model 1 (using independent variables of demographics and clinical factors), Model 2 (using procedures and therapies administered at any time during ICU admission in addition to the variables in Model 1). Using the test dataset, 8 variables (except for gender) were included in multiple logistic regression analysis with in-hospital mortality as the dependent variable, and the mortality prediction equation was constructed. Coefficients from the equation were then tested in the validation model. RESULTS: Hosmer-Lemeshow χ(2) are values for the test dataset in Model 1 and Model 2, and were 11.9 (P = 0.15) and 15.6 (P = 0.05), respectively; C-statistics for the test dataset in Model 1and Model 2 were 0.70 and 0.78, respectively. In-hospital mortality prediction for the validation datasets showed low and moderate accuracy in Model 1 and Model 2, respectively. CONCLUSIONS: Model 2 may potentially serve as an alternative model for predicting mortality in mechanically ventilated patients, who have so far required physiological data for the accurate prediction of outcomes. Model 2 may facilitate the comparative evaluation of in-hospital mortality in multicenter analyses based on administrative data for mechanically ventilated patients.

Derivation and validation of in-hospital mortality prediction models in ischaemic stroke patients using administrative data.

BACKGROUND: Stroke and other cerebrovascular diseases are a major cause of death and disability. Predicting in-hospital mortality in ischaemic stroke patients can help to identify high-risk patients and guide treatment approaches. Chart reviews provide important clinical information for mortality prediction, but are laborious and limiting in sample sizes. Administrative data allow for large-scale multi-institutional analyses but lack the necessary clinical information for outcome research. However, administrative claims data in Japan has seen the recent inclusion of patient consciousness and disability information, which may allow more accurate mortality prediction using administrative data alone. The aim of this study was to derive and validate models to predict in-hospital mortality in patients admitted for ischaemic stroke using administrative data. METHODS: The sample consisted of 21,445 patients from 176 Japanese hospitals, who were randomly divided into derivation and validation subgroups. Multivariable logistic regression models were developed using 7- and 30-day and overall in-hospital mortality as dependent variables. Independent variables included patient age, sex, comorbidities upon admission, Japan Coma Scale (JCS) score, Barthel Index score, modified Rankin Scale (mRS) score, and admissions after hours and on weekends/public holidays. Models were developed in the derivation subgroup, and coefficients from these models were applied to the validation subgroup. Predictive ability was analysed using C-statistics; calibration was evaluated with Hosmer-Lemeshow χ(2) tests. RESULTS: All three models showed predictive abilities similar or surpassing that of chart review-based models. The C-statistics were highest in the 7-day in-hospital mortality prediction model, at 0.906 and 0.901 in the derivation and validation subgroups, respectively. For the 30-day in-hospital mortality prediction models, the C-statistics for the derivation and validation subgroups were 0.893 and 0.872, respectively; in overall in-hospital mortality prediction these values were 0.883 and 0.876. CONCLUSIONS: In this study, we have derived and validated in-hospital mortality prediction models for three different time spans using a large population of ischaemic stroke patients in a multi-institutional analysis. The recent inclusion of JCS, Barthel Index, and mRS scores in Japanese administrative data has allowed the prediction of in-hospital mortality with accuracy comparable to that of chart review analyses. The models developed using administrative data had consistently high predictive abilities for all models in both the derivation and validation subgroups. These results have implications in the role of administrative data in future mortality prediction analyses.

Effect of certified training facilities for intensive care specialists on mortality in Japan.

OBJECTIVE: To compare patient outcomes in hospitals certified by the Japanese Society of Intensive Care Medicine (JSICM) as training facilities for intensive care specialists with patient outcomes in hospitals not certified by the JSICM (non-CFs). DESIGN: A retrospective case-control study using administrative data. MAIN OUTCOME MEASURE: Inhospital mortality. RESULTS: 164 803 intensive care unit admissions were identified between 1 April 2008 and 31 March 2010, of which 159 540 were for adults (≥18 years). A total of 50 875 patients in 125 hospitals were admitted to certified facilities (CFs) and 108 665 patients in 309 hospitals were admitted to non-CFs. Inhospital mortality rates were 9.9% and 10.6% in CFs and non-CFs, respectively (P < 0.001). After adjusting for age, emergency admission, admission route, use of vasopressors, mechanical ventilation, and renal replacement therapy, the odds ratio for hospital mortality in CF-treated patients was 0.81 (95% confidence interval, 0.78-0.85). The c statistic of the model was 0.881. CONCLUSIONS: Patients admitted to the intensive care unit in CFs had better outcomes. To improve patient outcomes, more board-certified intensivists are required in Japan.

Development and validation of an acute heart failure-specific mortality predictive model based on administrative data.

BACKGROUND: Acute heart failure (AHF) with its high in-hospital mortality is an increasing burden on healthcare systems worldwide, and comparing hospital performance is required for improving hospital management efficiency. However, it is difficult to distinguish patient severity from individual hospital care effects. The aim of this study was to develop a risk adjustment model to predict in-hospital mortality for AHF using routinely available administrative data. METHODS: Administrative data were extracted from 86 acute care hospitals in Japan. We identified 8620 hospitalized patients with AHF from April 2010 to March 2011. Multivariable logistic regression analyses were conducted to analyze various patient factors that might affect mortality. Two predictive models (models 1 and 2; without and with New York Heart Association functional class, respectively) were developed and bootstrapping was used for internal validation. Expected mortality rates were then calculated for each hospital by applying model 2. RESULTS: The overall in-hospital mortality rate was 7.1%. Factors independently associated with higher in-hospital mortality included advanced age, New York Heart Association class, and severe respiratory failure. In contrast, comorbid hypertension, ischemic heart disease, and atrial fibrillation/flutter were found to be associated with lower in-hospital mortality. Both model 1 and model 2 demonstrated good discrimination with c-statistics of 0.76 (95% confidence interval, 0.74-0.78) and 0.80 (95% confidence interval, 0.78-0.82), respectively, and good calibration after bootstrap correction, with better results in model 2. CONCLUSIONS: Factors identifiable from administrative data were able to accurately predict in-hospital mortality. Application of our model might facilitate risk adjustment for AHF and can contribute to hospital evaluations.