Intensive care unit admission has minimal impact on long-term mortality

OBJECTIVE To measure the association between intensive care unit (ICU) admission and both hospital and long-term mortality, separate from the effect of hospital admission alone. DESIGN Retrospective cohort study. SETTING All hospitals in British Columbia, Canada, during 3 fiscal years, 1994 to 1996. PATIENTS A total of 27,103 patients admitted to ICU and 41,308 (5% random sample) patients admitted to hospital but not to ICU. INTERVENTION None. MEASUREMENTS AND MAIN RESULTS Although ICU admission was an important factor associated with hospital mortality (odds ratio9.12; 95% confidence interval8.34–9.96), the association between ICU admission and mortality after discharge was relatively minimal (hazard ratio1.21; 95% confidence interval1.17–1.27) and was completely overshadowed by the effect of age, gender, and diagnosis. CONCLUSIONS After controlling for the effect of hospital admission, admission to ICU has minimal independent effect on mortality after discharge.