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.
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.
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 the 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