Background: We estimated stroke risk associated with new exposure to haloperidol, or any typical antipsychotic, versus atypical antipsychotic among patients aged ≥65 years regardless of dementia status.

Methods: IBM MarketScan Medicare Supplemental Database data (January 1, 2001 to December 31, 2017) were used. Stroke risk for new users of typical antipsychotics (T1 cohort) or haloperidol (T2 cohort) was compared with new users of atypical antipsychotics (C1 cohort) aged ≥65 years. Crude incidence rate (IR) and incidence proportion of stroke were estimated within each cohort and gender subgroup. Three propensity score (PS) matching strategies were employed: Unadjusted (crude), Sentinel PS replication, and a large-scale regularized regression model (adapted PS).

Results: Overall, 36,734 (T1), 24,074 (T2), and 226,990 (C1) patients were included. Crude IRs for stroke per 1000 person-years were 17.67 (T1), 23.74 (T2), and 14.17 (C1). In preplanned analyses, PS-matched calibrated hazard ratio (cHR) for stroke T1 versus C1 cohort was 1.08 (95% calibrated confidence interval [cCI] = 0.75, 1.55) with Sentinel PS strategy and 1.31 (95% cCI = 1.07, 1.60) with adapted PS strategy. The cHR for stroke in patients of T2 versus C1 was 1.69 (95% cCI = 1.08, 2.75) with Sentinel PS strategy and 1.45 (95% cCI = 1.17, 1.80) with adapted PS strategy.

Conclusion: Stroke risk in elderly new users of haloperidol was elevated compared to new users of atypical antipsychotics and was elevated for typical antipsychotics using the adapted PS strategy.