Abstract
OBJECTIVES: To determine the prognostic value of apathy for mortality in patients of somatic (SC) and dementia special care (DSC) nursing home (NH) units. DESIGN: Longitudinal design, secondary analyses of a 2-year, cluster-randomized trial with six measurements, approximately 4 months in between. SETTING: SC and DSC-units of Dutch NHs. PARTICIPANTS: NH-patients of seventeen SC-units (n = 342) and sixteen DCS-units (n = 371). MEASUREMENTS: Data were available for 713 NH-patients, 266 of whom died during the study. Apathy was assessed using the 10-item Apathy Evaluation Scale (AES-10) and applied as categorical variable using known cut-off scores as well as dimensional variable. Additionally, depressive symptoms were assessed using the Cornell Scale for Depression in Dementia. RESULTS: Mixed effects cox models using the coxme package in R revealed a higher risk of mortality between two measurements, if apathy was present (hazard ratio (HR) = 1.77; 95% confidence interval (CI] = 1.35-2.31, P < .001). Results remained significant (HR = 1.64; 95% CI = 1.23-2.19, P < .001) when controlled for depressive symptoms. DSC-units and SC-units did not differ (P > .05) in the effect of apathy on mortality. Male gender (HR = 1.67; 95% CI = 1.23-2.27, P < .001), and higher age in years (HR = 1.06; 95% CI = 1.04-1.08, P < .001) were also predictors of mortality. Regarding apathy as a dimensional construct, one standard deviation increase of AES-10 scores was associated with a 62% increase of mortality risk (HR = 1.62, 95% CI = 1.40-1.88, P < .001). CONCLUSIONS: Apathy was associated with mortality over a 4-month period in NH patients, even when controlling for depression. These data suggest that screening and treatment strategies for apathy should be developed for this patient population.
