Background: Few studies have evaluated the association between anticholinergic use and mortality in elderly nursing home residents.
Objective: The aim of this study was to examine the risk of mortality associated with anticholinergic use among elderly nursing home residents with depression.
Methods: The study employed a population-based nested case-control design using 2007-2010 Minimum Data Set (MDS)-linked Medicare data from all states. The base cohort included Medicare beneficiaries aged ≥65 years, diagnosed with depression as of 2007, and with any MDS assessment in 2007. Cases were identified as patients who died anytime between January 1, 2008 and December 31, 2010. For each case, four age- and sex-matched controls were selected using incidence density sampling. Anticholinergic exposure was defined using the Anticholinergic Drug Scale (ADS). Prescription of clinically significant anticholinergic medications (ADS level 2/3) 60 days preceding the event date formed the primary exposure. Conditional logistic regression model stratified on matched case-control sets was performed to assess mortality risk, after controlling for other risk factors.
Results: The study sample included 44,948 cases who died and 179,792 matched controls. After adjusting for other risk factors, clinically significant anticholinergic use was associated with significant risk of death (odds ratio [OR] 1.31; 95% CI 1.28-1.34) compared with non-use. Level-specific analysis indicated high mortality risk with only markedly anticholinergic (ADS level 3) medication use (OR 1.46; 95% CI 1.42-1.51).
Conclusions: Use of clinically significant anticholinergic medications was associated with a 31% increase in risk of mortality among elderly nursing home residents with depression. With increasing safety concerns, there is a significant need to optimize anticholinergic use in the vulnerable population.