Nandita Kachru, Ryan M. Carnahan, Michael L. Johnson, Rajender R. Aparasu

Inappropriate medications are often used in older adults despite their unfavourable risk-to-benefit profile. Although many of the medications in the American Geriatrics Society (AGS) Beers list are potentially inappropriate because of their anticholinergic properties, little is known regarding the nature and extent of potentially inappropriate anticholinergic medication use in older adults. To determine the prevalence of, and factors associated with, potentially inappropriate anticholinergic medication use in the older population. A retrospective, cross-sectional study was conducted, involving older adults (aged 65 years and older), using 2009-2010 Medical Expenditure Panel Survey (MEPS) data. The 2012 AGS Beers Criteria were used to define potentially inappropriate anticholinergic medications on the basis of the list of medications to avoid using in older adults irrespective of the diagnosis. Descriptive analyses were used to examine the nature and extent of potentially inappropriate anticholinergic medication use. Multivariable logistic regression within the conceptual framework of the Andersen Behavioral Model was used to identify the factors associated with potentially inappropriate anticholinergic use in older adults. According to the MEPS, there were 78.60 million older adults in the USA; an estimated 7.51 million (9.56 %) of these older adults used potentially inappropriate anticholinergic medications in 2009-2010. The most frequently used potentially inappropriate anticholinergics were cyclobenzaprine, promethazine, amitriptyline, hydroxyzine and dicyclomine. Multivariable regression analyses revealed that female sex, residing in the South and the presence of anxiety disorder increased the likelihood of receiving potentially inappropriate anticholinergic medications, whereas older adults aged 75-84 or ≥85 years, and those with over 15 years of education, had a decreased likelihood of receiving potentially inappropriate anticholinergic medications. The study found that approximately one in ten older adults used potentially inappropriate anticholinergic medications. Several predisposing, enabling and need factors were associated with the use of potentially inappropriate anticholinergic medications. Concerted efforts are needed to optimize potentially inappropriate anticholinergic medication use in older adults.