Prevalence and factors associated with anticholinergic medication use in community-dwelling older adults: a systematic review.

Introduction: Medications with anticholinergic effects are widely used despite the mounting evidence of physical and cognitive impairment associated with their use among older adults.

Aim: A systematic review was conducted to describe the prevalence of anticholinergic medication use in community-dwelling older adults, document the factors associated with their use and describe the most frequently used medication classes.

Method: MEDLINE, Embase and CINAHL were searched from inception to May 2024. All study designs except case reports and case studies were eligible if they included community-dwelling older adults aged 65 and older and assessed the factors associated with anticholinergic medication use. An open-source artificial intelligence screening tool was used to optimise title and abstract screening. The subsequent review of the full texts of potentially eligible studies and data extraction were conducted in the Covidence systematic review tool using standardised data collection forms. Study quality was assessed with the Newcastle-Ottawa scale. The study selection, data extraction and quality assessment were conducted independently by two reviewers.

Results: From 4139 records of interest, the seven selected studies included five cross-sectional and two retrospective studies, published between 2014 and 2021. The risk of bias was assessed to be low in five studies and high in two studies. Greater anticholinergic burden was associated with female sex, lower socioeconomic status, higher co-morbidity score, higher frailty probability, specific diseases, polypharmacy and greater use of healthcare, while increasing age was associated with both increased and decreased anticholinergic burden. Anticholinergic exposure, varied from a low of 6.2% of medical visits in the United States between 2006 and 2015, assessed with the 2015 Beers Criteria and the Anticholinergic Risk Scale, to a high of 72.8% of medication claims (dispensed medications) in South Korea, over the year 2012, assessed with the 2015 Beers Criteria and the Anticholinergic Burden Scale. The use of six different anticholinergic scales and different evaluation periods did not allow a meaningful comparison of the prevalence of anticholinergic exposure across studies. Antidepressants, antihistamines and antimuscarinics were the most common medication classes in the two studies using this classification.

Conclusion: This systematic review documented key socioeconomic and health status factors to be targeted by interventions aimed at limiting the use of anticholinergic medications in community-dwelling older adults.