Antipsychotic Use and Risk of Nursing Home Admission Among Dual-Eligible Medicare Beneficiaries: A Propensity-Matched Study

BACKGROUND: Antipsychotic use is associated with serious adverse events in the elderly, and consequently can lead to further healthcare utilization such as nursing home admission. OBJECTIVE: To evaluate the risk of nursing home admission associated with typical versus atypical antipsychotic use among the US community-dwelling elderly population. METHODS: A retrospective cohort design was conducted using Medicare and Medicaid Analytical eXtract (MAX) data from four US states. The cohort included all dual-eligible beneficiaries (aged ≥65 years) who initiated antipsychotic treatment during July 2001–December 2003. The risk of nursing home admission during the 6-month follow-up period was evaluated using Cox proportional hazards regression model and extended Cox model stratified on matched pairs based on propensity score, using atypical agents as the reference category. RESULTS: The average risk of nursing home admission was similar among atypical antipsychotic users compared to typical users (hazard ratio [HR] 0.91; 95 % confidence interval [CI] 0.81–1.01]) However, the results of extended Cox regression revealed that the effect varied with time; typical users had a moderately lower risk of nursing home admission within the initial 90 days of therapy [HR 0.87; 95 % CI 0.77–0.97] but substantial risk was observed for 90–180 days of typical antipsychotic exposure [HR 1.58; 95 % CI 1.08–2.12]. CONCLUSION: The study found that, among elderly beneficiaries, typical antipsychotic use was associated with a time-dependent increase in risk of nursing home admission. Given the safety concerns with atypical antipsychotics and their extensive use in the elderly, there is a need to be cautious while prescribing antipsychotics in the vulnerable elderly population.