Antipsychotic Drugs and Hip Fracture: Associations Before and After the Initiation of Treatment.

OBJECTIVE

To study the association between antipsychotic drug treatment and hip fracture, before and after the initiation of treatment.

DESIGN

Nationwide cohort study.

SETTING AND

PARTICIPANTS

In this study based on several Swedish registers, all individuals age ≥65 years who filled prescriptions for antipsychotic drugs in 2007-2017 were matched 1:1 by sex and age with controls, resulting in a cohort of 255,274 individuals.

MEASURES: Associations between antipsychotic drug treatment and hip fracture were investigated using multivariable conditional logistic regression models and flexible parametric survival models for nonproportional hazards, starting 1 year before the first prescription was filled and extending to 1 year thereafter.

RESULTS

The studied cohort had a mean age of 81.5 (standard deviation, 8.1) years; 152,890 (59.9%) individuals were women. Antipsychotic drug use was associated with an increased risk of hip fracture in all studied time frames, before and after the initiation of treatment. The risk was highest 16-30 days before the initiation of treatment (odds ratio 9.09; 95% confidence interval 7.00-11.81). The pattern was consistent in subgroup analyses of users of conventional and atypical antipsychotics, men and women, as well as in younger old and older old participants. The association with hip fracture was not influenced by antipsychotic drug dose.

CONCLUSIONS AND IMPLICATIONS: The association between antipsychotic drug use and the risk of hip fracture was observed before the initiation of antipsychotic treatment. This finding suggests that factors other than exposure to antipsychotic drugs are responsible for the increased risk of hip fracture in the treatment group.