Mortality and institutionalization of patients with dementia treated in primary care: influence of neuropsychiatric symptoms (NeDEM project)

Abstract

Background: Neuropsychiatric symptoms (NPSs) are common in people with dementia (PWD), but their associations with the risk of institutionalization and mortality are controversial. The objective of this study was to estimate the incidence of institutionalization and death among PWD treated in primary care (PC) and to analyse the associations between NPSs and these events. Methods: This was a longitudinal analytical observational study of PWD in PC with a 4-year follow-up. Data on sociodemographic, clinical and functional characteristics and prescribed treatments for dementia were collected. NPSs were examined with the Neuropsychiatric Inventory (NPI) scale and according to the presence of clinically relevant neuropsychiatric subsyndromes. The incidence of institutionalization and cumulative mortality were calculated annually and at four years. Survival analysis with Kaplan‒Meier curves and Cox regression was performed to analyse the influence of NPSs on institutionalization and mortality. Results: A total of 124 patients with a mean age of 82.5 (8.0) years were included, and 69.4% were women. At four years, the institutionalization rate in a nursing home was 29.8% (95% CI 22.0; 38.7), with a median time to institutionalization of 13.2 months (IQR: 6.8–31.5). The mortality rate was 48.4% (95% CI 39.3; 57.5), with a median survival time of 21.7 months (IQR: 14.2–32.0). The NPI score was associated with institutionalization (HR 1.27, 95% CI 1.12, 1.45) and mortality (HR 1.47, 95% CI 1.40, 1.54). Among the subsyndromes, the presence of clinically relevant apathy was associated with institutionalization (HR 2.23, 95% CI 1.29, 3.88) and mortality (HR 1.56, 95% CI 1.34, 1.81). Conclusions: In PWD who were followed up in the community for four years, one-third of the patients were institutionalized, and half died. The intensity of the NPSs influences both institutionalization and mortality, with subsyndrome apathy (formed by the symptoms of apathy and appetite alterations) being the one that most influences both outcomes.