Risk of falls and fractures in older adults using atypical antipsychotic agents: a propensity score-adjusted, retrospective cohort study.

Background: Atypical antipsychotic agents are extensively prescribed in the elderly to treat various behavioral and psychiatric disorders. Past literature has documented an increased risk of falls and factures with the use of risperidone and olanzapine compared with nonuse. However, none of the studies assessed the comparative safety profiles of atypical agents with respect to falls and fractures.

Objective: The goal of this study was to evaluate the risk of falls and fractures associated with the use of risperidone, olanzapine, and quetiapine in community-dwelling adults aged ≥50 years.

Methods: The study involved a propensity score-adjusted approach in new users of risperidone, olanzapine, or quetiapine anytime between July 1, 2000, and June 30, 2008, using data from the IMS LifeLink Health Plan Claims database. Patients were followed up until a hospitalization/emergency department visit for fall/fracture or the end of the study period, whichever occurred earlier. The Cox proportional hazards regression model was used to evaluate the comparative risk of falls/fractures. The covariates in the final model included propensity scores and their interaction terms.

Results: There were 12,145 new users of atypical agents in the study population (5083 risperidone, 4377 olanzapine, and 2685 quetiapine). A total of 417 cases of falls/fractures with at least 1 hospitalization/ emergency department visit after the use of the antipsychotic agents were identified. The number of falls for risperidone, olanzapine, and quetiapine were 179 (3.56%), 123 (2.84%), and 115 (4.34%), respectively. After adjusting for propensity scores, the Cox proportional hazards model showed that there was no statistically significant difference with use of risperidone (hazard ratio = 1.10 [95% CI, 0.86-1.39]) or quetiapine (hazard ratio = 1.12 [95% CI, 0.86-1.46]) compared with olanzapine (reference group) in the risk of falls or fractures.

Conclusions: The study found no significant difference across the individual atypical agents in the risk of falls/fractures in community-dwelling older adults. Future studies are required to evaluate the overall safety profiles of the antipsychotic agents in this population.