The use of antipsychotics is associated with lower mortality in patients with Alzheimer's disease: A nationwide population-based nested case-control study in Taiwan.

Objective: The purpose of this study was to identify the association between antipsychotics and mortality in Alzheimer's disease patients. Methods: Using the Taiwan National Health Insurance Research Database, 735 newly diagnosed Alzheimer's disease patients aged over 65 years and receiving antipsychotic treatments, and 735 age, sex, physical comorbidity, and entry year with propensity scores, matched control subjects were enrolled and followed for a 10-year period until the end of 2011. Multivariate Cox proportional hazards regression models were used for analysis. Results: The mortality rate was 56% in Alzheimer's disease patients treated with antipsychotics, and 65% in Alzheimer's disease patients not treated with antipsychotics during an average of 5.2 years of follow-up. The use of antipsychotics, typical antipsychotics, and atypical antipsychotics was found to be associated with lower mortality (adjusted hazard ratio=0.66, 95% confidence interval 0.58-0.75; 0.69, 0.60-0.79; 0.56, 0.44-0.71, respectively, all p<0.001). In addition, Alzheimer's disease patients with higher cumulative dose and longer duration of exposure to antipsychotics showed a significantly reduced risk of mortality. Other variables associated with higher risk of mortality included age (adjusted hazard ratio=1.08, 95% confidence interval 1.07-1.09, p<0.001), male gender (1.27, 1.11-1.45, p<0.001), diabetes mellitus (1.30, 1.10-1.54, p<0.01), congestive heart failure (1.54, 1.11-2.12, p<0.01), and stroke (1.23, 1.05-1.44, p<0.01). Conclusion: The use of antipsychotics was found to be associated with lower mortality in Alzheimer's disease patients. Moreover, dose and duration response effects were also identified.