Nursing home patients in the intensive care unit: Risk factors for mortality.

OBJECTIVE: To determine intensive care unit (ICU) admission characteristics predictive of mortality among older nursing home residents.

DESIGN: Retrospective cohort study.

SETTING: A 725-bed teaching nursing home and two teaching-hospital ICUs.

PATIENTS: One hundred twenty-three nursing home residents > or =75 yrs admitted to the ICU between July 1, 1999, and September 30, 2003.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Characteristics of nursing home residents admitted to the ICU were identified by medical record review at the nursing home and the hospital. Additionally, the minimum data set was used to calculate preadmission functional status using the Activities of Daily Living-Long Form (ADL-L) and cognitive status with the Cognitive Performance Scale (CPS). Our primary outcomes were hospital mortality and mortality within 90 days of ICU admission. The nursing home residents admitted to the ICU were old (87.7 +/- 5.4 yrs) with impaired cognition (CPS 2.8 +/- 1.7, range 0-6, where 6 = most impaired) and moderately dependent function (ADL-L 14.5 +/- 9.4, range 0-28, where 28 = total dependence). Of the 123 patients, 33 (27%) died in the hospital, whereas 90 (73%) survived to hospital discharge. Acute Physiology and Chronic Health Evaluation (APACHE) III score was independently associated with significantly increased odds of hospital mortality (adjusted odds ratio 1.04; 95% confidence interval 1.02, 1.07). Among the 90 patients who survived to return to the nursing home, 34 (37.8%) died within 90 days. Cox regression demonstrated that higher APACHE III score (adjusted risk ratio 1.02; 95% confidence interval 1.01, 1.04) and increasing functional dependency before ICU admission (adjusted risk ratio 1.6; 95% confidence interval 1.05, 2.57, per ADL-L quartile) were independently associated with increased mortality rate within 90 days.

CONCLUSIONS: Among vulnerable elderly nursing home residents, higher APACHE III score is independently associated with increased hospital mortality rate and mortality within 90 days. Among hospital survivors, impaired functional status is independently associated with increased mortality rate within 90 days.