A cross-cultural comparison of critical care delivery - Japan and the United States

Objective: To compare the utilization and outcomes of critical care services in a cohort of hospitals in the United States and Japan. Design: Prospective data collection on 5,107 patients and detailed organizational characteristics from each of the participating Japanese study hospitals between 1993 and 1995, with comparisons made to prospectively collected data on the 17,440 patients included in the US APACHE (acute physiology and chronic health evaluation) III database. Setting: Twenty-two Japanese and 40 US hospitals. Patients: Consecutive, unselected patients from medical, surgical, and mixed medical/ surgical ICUs. Measurements: Severity of illness, predicted risk of in-hospital death, and ICU and hospital length of stay (LOS) were assessed using APACHE III. Japanese ICU directors completed a detailed survey describing their units. Main results: US and Japanese ICUs have a similar array of modalities available for care. Only 1.0% (range, 0.56 to 2.7%) of beds in Japanese hospitals were designated as ICUs. The organization of the Japanese and US ICUs varied by hospital, but Japanese ICUs were more likely to be organized to care for heterogeneous diagnostic populations. Sample case-mix differences reflect different disease prevalence. ICU utilization for women is significantly lower (35.5% vs 44.8% of patients) and there were relatively fewer patients : 85 years old in the Japanese ICU cohort (1.2% vs 4.6%), despite a higher per capita rate of individuals : 85 years old in Japan. The utilization of ICUs for patients at low risk of death significantly less in Japan (10.2%) than in the United States (12.9%). The APACHE III score stratified patient risk. Overall mortality was similar in both national samples after accounting for differences in hospital LOS, utilizing a model that was highly discriminating (receiver operating characteristic, 0.87) when applied to the Japanese sample. The application of a US-based mortality model to a Japanese sample overpredicted mortality across all but the highest (>90%) deciles of risk. Significant variation in expected performance was noted between hospitals. Risk-adjusted ICU LOS was not significantly longer in Japan; however, total hospital stay was nearly twice that found in the US hospitals, reflecting differences in hospital utilization philosophies. Conclusions: Similar high-technology critical care is available in both countries. Variations in ICU utilization reflect differences in case-mix and bed availability. Japanese ICU utilization by gender reflects differences in disease prevalence, whereas differences in utilization by age may reflect differences in cultural norms regarding the limits of care. Such differences provide context from which to assess die delivery of care across international borders. Miscalibration of predictive models applied to international data samples highlight the impact that differences in resource use and local practice cultures have on outcomes. Models may require modification in order to account for these differences. Nevertheless, with large databases, it is possible to assess critical care delivery systems between countries accounting for differences in case-mix, severity of illness, and cultural normative standards facilitating the design and management such systems.