Background: The mortality rate after discharge from the intensive care unit (ICU) (so called post-ICU mortality) has remained high (8.6-23.6%) during the past 15 years. The object of this study was to examine the effects of the severity of illness at ICU discharge assessed using the Acute Physiology and Chronic Health Evaluation (APACHE) on the post-ICU mortality rate.
Methods: A 6-month prospective observational study was conducted in the medical ICU of a university affiliated tertiary care hospital.
Results: A total of 203 patients were discharged from the ICU to general wards from December 1998 through June 1999, and 39 (19.2%) of the 203 discharged ICU patients subsequently died at hospital. Logistic regression analysis identified two independent risk factors for post-ICU mortality rate: discharge APACHE II score (Odds Ratio 1.17, 95% IC 1.10-1.25, p < 0.0001) and male gender (OR 3.24, 95% CI 1.26-8.33, p = 0.015). Patients discharged from the ICU with discharge APACHE II scores of 17 or greater had the mortality rate of 37.3% compared with 9.4% for those with discharge APACHE II scores of less than 17. The former group were significantly older (p < 0.0001) and had higher proportion of requiring tracheostomy or hemodialysis during ICU admission (p < 0.0001) than the latter group.
Conclusion: In our study, a higher APACHE II score calculated at ICU discharge and male gender were independent risk factors for post-ICU death. Identifying patients with discharge APACHE II scores of 17 or greater helps to predict post-ICU death.