Resource-rich Intensive Care Units vs. Standard Intensive Care Units on Patient Mortality: A Nationwide Inpatient Database Study.

Introduction In this present study, we aimed to assess whether care in resource-rich intensive care unit (ICU) was associated with lower ICU mortality compared with care in standard ICU. Methods This retrospective cohort study used administrative data that are routinely collected in Japan. Using the Japanese Diagnosis Procedure Combination inpatient database, we identified patients aged >15 years who were admitted to the ICU from April 2016 to March 2019. We defined resource-rich ICUs as ICUs with two or more intensivists as full-time employees, ≥20 m2 per ICU bed, and a medical engineer in the hospital 24 hours per day; other ICUs were categorized as standard ICUs. The primary outcome was ICU mortality. A generalized estimating equation approach with ICUs as the clusters was used to compare ICU mortality between the two groups. Results Of the 789,630 eligible patients from 458 ICUs, 237,138 (30%) were treated in the 111 resource-rich ICUs, whereas 552,492 (70%) were treated in the 347 standard ICUs. The crude ICU mortality rate was 3.6% (8443/237,138) among patients admitted to resource-rich ICUs, while it was 4.3% (23,490/552,492) among those admitted to standard ICUs. The results of the generalized estimating equation analysis showed that patients treated in resource-rich ICUs tended to have lower ICU mortality compared to patients treated in standard ICUs (difference, -0.4%; 95% confidence interval, -0.8%-0.0%). Conclusions The findings of this nationwide study suggest that, compared with care in standard ICUs, care in resource-rich ICUs is associated with lower ICU mortality. This study showed the overall effect of treatment in hospitals with resource-rich ICUs including intensivist staffing and greater hospital resources. Further studies are required to assess the effects of organizational factors on mortality.