Treatment changes among older patients with dementia treated with antipsychotics

Abstract

Background: Prescribing practice patterns and factors associated with treatment changes in older patients initiating antipsychotic treatment for the behavioral and psychological symptoms of dementia is not well known.

Objectives: The objective of this study is to study 90-day prescribing practice patterns across the three most commonly prescribed antipsychotics.

Methods: This is a retrospective study using national data from the US Department of Veterans Affairs (VA). The study included patients older than 65 years diagnosed with dementia who began outpatient treatment with an antipsychotic medication between 2005 and 2008. Patients were followed for 90 days from their antipsychotic start. The primary event of interest was changing to another psychotropic medication. Cumulative incidence of treatment change was determined with antipsychotic discontinuation and death as competing risks. Covariate-adjusted hazard ratios for treatment change were determined using competing risk regression models.

Results: During the study period, 15,435 patients initiated an atypical antipsychotic; 14,791 started olanzapine, quetiapine, or risperidone. Over half (55%) of the patients discontinued index treatment within 90 days, 36% continued, 3% died while on index treatment, and 6% changed to another psychotropic medication. Compared with quetiapine, the adjusted hazard of treatment change was higher by 43% (p = 0.005) for olanzapine and by 12% (p = 0.08) for risperidone.

Conclusion: The higher hazard of treatment change with olanzapine suggests patients either responded worse to or experienced more adverse events with olanzapine compared with quetiapine.

Keywords: atypical antipsychotics; dementia; older patients; treatment change.

Figure 1

(1a) Cause-specific hazards for changing treatment over the initial 90 days of newly initiating an antipsychotic agent. (1b) Cumulative incidence function of changing to other psychotropic medication within 90 days of the newly initiating an antipsychotic agent based on competing risk regression model.