Long-term functional outcome after intensive care

OBJECTIVE: Although age-related mortality after intensive care unit (ICU) admission has been studied, functional recovery for different age groups following ICU admission is not well characterized. We hypothesized that compared with younger age groups, fewer patients older than age 65 admitted to an ICU would regain their full prehospitalization functional ability and that their recovery would be slower than that of younger patients. DESIGN: A prospective observational cohort study with convenience sampling. SETTING: Intensive care units of an urban university-affiliated Veterans Administration Medical Center. PARTICIPANTS: A total of 222 patients during the first 72 hours after entry to a medical or surgical ICU at the Denver Veteran's Administration Medical Center between September 1991 and July 1992. MEASUREMENTS: We collected baseline data on patient demographics and on the severity of acute illness using the Acute Physiology and Chronic Health Evaluation (APACHE II), Acute Physiology Score (APS), and functional status (highest level of physical activity level 1 month before admission). We recorded survival and patient-perceived global functional status at 6 weeks and 6 months after admission. Post-ICU function was adjusted for baseline function, age, APACHE II, and APS using multiple regression. RESULTS: Average patient age was 62 +/- .74 years (mean +/- SEM). Fifty-two percent of the entire cohort returned to baseline function at 6 months. Although baseline function was better for younger people, there was no difference in recovery at 6 weeks in older compared with younger patients. Most functional recovery occurred by 6 weeks, with maintenance of this recovery at 6 months. Baseline function was the major determinant of both 6 week recovery (P <.001) and 6 month recovery (P =.002), whereas APACHE II was not (P =.3). Age predicted recovery significantly (P =.04) at 6 months but not at 6 weeks (P =.26). APACHE II (P <.001) and baseline function (P =.03) predicted mortality. CONCLUSIONS: Older people had worse functional ability at ICU admission, but the proportion of older people who recovered and their rate of recovery was the same as for younger people. Baseline functional status, rather than abnormal physiologic status (as measured by APACHE II) on admission, was the major determinant of recovery, whereas APACHE II was the main correlate of mortality. Together, baseline function and physiologic status provide valuable complementary information for clinically relevant outcomes following an ICU admission.