Investigating the association between atypical antipsychotic medication use and falls among personal care home residents in the Winnipeg Health Region

Abstract

Falls among older adults (age 65 years and older) residing in personal care homes (PCHs) are an important health concern. Atypical antipsychotic drugs (AADs) have been shown to be associated with fall risk among older adults. However, previous studies face some methodological limitations that affect the quality, consistency, and comparability of these studies. Therefore, a population-based study was undertaken to examine the effect of AAD use on the risk of falling among older PCH residents. A nested case-control study was conducted using the administrative healthcare records and Minimum Data Set for PCHs (MDS) housed at the Manitoba Centre for Health Policy in the Faculty of Medicine, University of Manitoba. The study period was from April 1, 2005 to March 31, 2007. Cases (n=626) were fallers as recorded in MDS. Using incidence density sampling, each case was matched to four controls on length of PCH stay, age, and sex (n=2,388). Exposure to AADs was obtained from the Drug Program Information Network database. Conditional logistic regression was used to model the effects of AAD use on the risk of falling while accounting for matching and for confounding of other covariates. While the adjusted odds of falling was statistically greater for AAD users versus nonusers (adjusted odds ratio = 1.60, 95% CI 1.10-2.32), this association was type and dose dependent. Compared to nonusers, the odds of falling was greater for quetiapine users, regardless of this drug's dose, and high dose risperidone users. On the other hand, low dose risperidone and olanzapine, irrespective of drug dose, use was not associated with the risk of falling. Furthermore, the effect of AAD use, in general, on the risk of falling was significantly greater for people with wandering problems (adjusted odds ratio = 1.84, 95% CI 1.09-3.09). Despite some methodological limitations, this research has provided some unique findings that enhance our understanding of AAD use as a fall risk factor. Study findings allow policymakers to further develop evidence-based interventions specific to AADs in order to better manage falls in the PCH setting. However, a great deal of research is still needed to address other important unanswered questions.