Predictors of short-term functional decline in survivors of nursing home-acquired lower respiratory tract infection.

Abstract

Scant information exists about the risk of functional decline following treatment of acute illness in the nursing home (NH) setting. The aim of this study was to determine the incidence of short-term (30-day) functional decline among survivors of NH-acquired lower respiratory tract infection (LRI) and the factors that predict such decline, including the role of initial hospitalization. We used a prospective cohort design to study 781 episodes of LRI in 1044 NH residents in 36 NHs in central Missouri and the St. Louis metropolitan area. Functional decline was defined as a 3-point increase on the Minimum Data Set (MDS) activities of daily living (ADL) long form scale. Of 781 LRI cases who survived to 30 days, the incidence of ADL decline was 28.8%. In a logistic regression model that used generalized estimating equations to adjust for clustering, variables associated with ADL decline included the following: chronic feeding tube use (AOR = 4.54, 95% confidence interval, or CI, 1.61, 12.80), decubitus ulcer (adjusted odds ratio [AOR] = 2.29, 95% CI 1.35, 3.90), shortness of breath (AOR = 2.18, 95% CI 1.44, 3.30), short-term memory problems (AOR = 2.07, 95% CI 1.33, 3.23), decline in self-performance of toilet use in the 24 hours prior to evaluation (AOR = 1.65, 95% CI 1.29, 2.12), age (AOR = 1.02, 95% CI 1.00, 1.05), and baseline ADL score. Addition of treatment variables to the model showed that initial hospitalization was also associated with ADL decline (AOR = 1.90, 95% CI 1.20, 3.00). Residents with ADL decline at 30 days were less likely to recover to their baseline ADL status at 90 days. Many NH residents who survive to 30 days following LRI develop new functional limitations, and such individuals are at risk for ADL decline at 90 days. A limited number of clinical variables may predict short-term functional decline. Initial hospitalization for acute treatment of LRI may increase the risk of subsequent ADL decline among individuals who survive to 30 days.