Atypical Antipsychotics and the Risk of Falls and Fractures Among Older Adults: An Emulation Analysis and an Evaluation of Additional Confounding Control Strategies.

PURPOSE: The aim of this study was to investigate the risk of falls and fractures among older adults receiving atypical antipsychotics.

METHODS: An emulation analysis of a previously published study was performed using the US Truven MarketScan Medicare Supplemental database (MDCR). In addition, modified analyses were implemented to evaluate alternative confounding control strategies that (1) included all covariates used to fit propensity score models in outcome models and (2) required patients to have a mental health condition diagnosis and a health care visit within 90 days prior to the index date.

FINDINGS: The MDCR emulation analyses yielded similar results as the previous study. For the previous study and our emulation analysis, the results were: nonvertebral osteoporotic fractures (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.41-1.60; and OR, 1.49; 95% CI, 1.37-1.63, respectively), hip fractures (OR, 1.67; 95% CI, 1.53-1.81; and OR, 1.59; 95% CI, 1.43-1.77, respectively), any fracture (OR, 1.29; 95% CI, 1.24-1.34; and OR, 1.32; 95% CI, 1.23-1.41, respectively), and falls (OR, 1.54; 95% CI, 1.47-1.61; and OR, 1.45; 95% CI, 1.11-1.89, respectively). However, in modified analyses, no associations were significant. The primary change that resulted in the attenuation of associations was the requirement for patients to have a mental health condition diagnosis and a health care visit prior to the index date.

CONCLUSIONS: Our MDCR emulation analysis yielded similar results as a previous study; however, in modified analyses, the associations between fractures and falls and atypical antipsychotics were no longer significant. The contrast of results between the emulation and modified analyses may be due to the analytic approach used to compare patients (and potential confounding by indication). Further research is warranted to evaluate these associations.