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.