A Longitudinal Treatment Effect Analysis of Antipsychotics on Behavior of Residents in Long-Term Care

Objective: The proportion of long-term care (LTC) residents being treated with antipsychotic medication is high, and these medications may exacerbate behavioral symptoms. We used propensity scores to investigate the effect of antipsychotic use on the worsening of behavioral symptoms among residents in LTC facilities. Design: A retrospective study. Setting and participants: Residents in LTC in 8 provinces and 1 territory in Canada, without severe aggressive behavior at baseline and reassessed at follow-up, between March 2000 and March 2022. Methods: We used propensity score matching and weighting to balance baseline covariates and logistic regression to estimate the effect of antipsychotics on the worsening of behavioral symptoms in the original, matched, and weighted cohorts. The treatment variable was use of antipsychotic medication at baseline and the outcome was worsening of behavior at follow-up. Results: A total of 494,215 participants were included [318,234 women and 175,981 men; mean age 82.8 years (SD 10.1; range 18–112)].130 558 (26.4%) used antipsychotics at baseline and 88,632 (17.9%) had worsening behavior in follow-up. In the matched cohort, there were 249,698 participants, and 124,849 were matched (1:1) in each treatment group. There was a significant association between antipsychotic use at baseline and worsening in behavior at follow-up in the adjusted regression models [OR 1.27 (95% CI 1.25–1.29), <0.0001] as well as in matched [OR 1.20 (95% CI 1.17–1.21), <0.0001] and weighted [OR 1.26 (95% CI 1.24–1.28), <0.0001] cohorts. Conclusions and implications: This study further evidence to support the cautious use of antipsychotics in LTC facilities. Future research in LTC facilities could include a more granular analyses of behavior change, including bidirectional analyses between different symptom severity classifications.