OBJECTIVE: Although age-related mortality after intensive care unit (ICU) a
dmission has been studied, functional recovery for different age groups fol
lowing ICU admission is not well characterized. We hypothesized that compar
ed 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 Ad
ministration 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 Medica
l 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 Ev
aluation (APACHE II), Acute Physiology Score (APS), and functional status (
highest level of physical activity level 1 month before admission). We reco
rded survival and patient-perceived global functional status at 6 weeks and
6 months after admission. Post-ICU function was adjusted for baseline func
tion, 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. Al
though baseline function was better for younger people, there was no differ
ence in recovery at 6 weeks in older compared with younger patients. Most f
unctional recovery occurred by 6 weeks, with maintenance of this recovery a
t 6 months. Baseline function was the major determinant of both 6 week reco
very (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) predi
cted mortality. CONCLUSIONS: Older people had worse functional ability at I
CU admission, but the proportion of older people who recovered and their ra
te of recovery was the same as for younger people. Baseline functional stat
us, rather than abnormal physiologic status (as measured by APACHE II) on a
dmission, was the major determinant of recovery, whereas APACHE II was the
main correlate of mortality. Together, baseline function and physiologic st
atus provide valuable complementary information for clinically relevant out
comes following an ICU admission.