Risk of cerebrovascular adverse events in older adults using antipsychotic agents: a propensity-matched retrospective cohort study.

OBJECTIVE: To compare the risk of cerebrovascular adverse events with second-generation antipsychotic users versus those taking first-generation antipsychotics in community-dwelling older adults.

METHOD: A population-based retrospective cohort study matched on propensity score was used to examine the risk of cerebrovascular adverse events in second-generation antipsychotic users compared to first-generation antipsychotic users. IMS LifeLink Health Plan Claims Database was used to identify older adults (> or = 50 years) taking second-generation or first-generation antipsychotic agents from July 1, 2000, to December 31, 2007. Cox proportional hazards regression model stratified on matched pairs was used to examine the risk of hospitalization or emergency visits due to cerebrovascular adverse events within 1 year of follow-up (primary outcome measure). The covariates adjusted for include duration of therapy and exposure to other medication increasing risk of cerebrovascular adverse events.

RESULTS: A total of 11,160 older adults (5,580 second-generation and 5,580 first-generation antipsychotic users) matched on propensity score was obtained. Regression analysis revealed that no statistically significant difference exists between second-generation and first-generation antipsychotic users with respect to risk of cerebrovascular adverse events (hazard ratio [HR], 0.858; 95% CI, 0.689-1.446). However, duration of therapy between 30-90 days (HR, 1.707; 95% CI, 1.174-2.481) and more than 90 days (HR, 1.570; 95% CI, 1.132-2.176) was associated with increased risk of cerebrovascular adverse events compared to duration of therapy less than 30 days.

CONCLUSIONS: The use of second-generation antipsychotic agents was found not to be associated with increased risk of cerebrovascular adverse events compared to first-generation agents in older adults. However, long-term use of second- and first-generation antipsychotic agents is associated with increased risk of cerebrovascular adverse events.