Hallucinations, Antipsychotic Use, and Mortality in Older Adults with Dementia: Retrospective Cohort Study of Two Medicare-Linked National Health Surveys.

backgroundHallucinations are associated with earlier death in older adults with dementia, but antipsychotic medications are also associated with mortality, and comparisons of their relative harms are lacking.

objectiveTo determine the individual and combined association between hallucinations, antipsychotic use, and mortality.

methodsWe performed a retrospective cohort study using Medicare-linked survey data from two nationally representative studies (the National Health and Aging Trends Study and the Health and Retirement Study) containing validated dementia identification algorithms and a screening question for hallucinations. Using Medicare claims, we identified participants with dementia who had no history of antipsychotic use during the year of or prior to entry. We used extended Cox regression with time-varying covariates to analyze the association between hallucinations, antipsychotic use, and mortality adjusting for confounders.

resultsWe identified 1703 eligible subjects who contributed 4,819 person-years of follow-up. 555 (32.6%) had hallucinations at baseline, 705 (41.4%) reported hallucinations at least once during follow-up, and 284 (16.7%) received antipsychotics. Hallucinations were associated with an increased risk of death in unadjusted models (hazard ratio (HR) 1.36; 95% confidence interval (CI): 1.18-1.5), but antipsychotic use was not (HR 1.03; 95% CI 0.85-1.2). After adjusting for age, race, gender, dementia severity, and comorbidities, the HR for hallucinations attenuated and was no longer statistically significant (1.15, 95% CI 0.98-1.34). There was no significant interaction between hallucinations and antipsychotic use.

conclusionHallucinations are associated with an increased risk of death that is greater than the risk associated with antipsychotic use, though this is partially confounded by dementia severity and comorbidities.