Dana Clarissa Muhlack, Liesa Katharina Hoppe, Christian Stock, Walter E. Haefeli, Hermann Brenner, Ben Schöttker

To assess the changes in use of potentially inappropriate medication (PIM) as defined by the 2015 Beers criteria, the EU(7)-PIM, and the PRISCUS list over a 6-year period and to identify determinants for current and future PIM use with a particular focus on geriatric syndromes. In a German cohort of 2878 community-dwelling adults aged ≥ 60 years, determinants of the use of ≥ 1 PIM were identified in multivariable logistic regression (cross-sectional analysis) and weighted generalized estimating equation models (longitudinal analysis). Prevalences for Beers, EU(7), and PRISCUS PIM were 26.4, 37.4, and 13.7% at baseline and decreased to 23.1, 36.5, and 12.3%, respectively, 6 years later. Unadjusted prevalences in participants with any geriatric syndrome (frailty, co-morbidity, functional, or cognitive impairment) were approximately twice as high as in robust older adults. In multivariable analyses, cognitive impairment was statistically significantly associated with the use of PIM of all three criteria in the cross-sectional (odds ratio (OR) point estimates 1.90-2.21) but not in the longitudinal models. In contrast, frailty, co-morbidity, and functional impairment were statistically significantly associated with the use of PIM of at least one of the three criteria in both models. However, the associations varied for the PIM criteria, and in the longitudinal analysis, associations were only statistically significant for Beers PIM (ORs [95% confidence intervals]: frailty (2.23 [1.15, 4.31]), co-morbidity by five total co-morbidity score points (1.21 [1.05, 1.38]), and functional impairment (1.51 [1.00, 2.27]). Other statistically significant determinants of the incidence of PIM (any definition) were female sex, age, coronary heart disease, heart failure, biomarkers of the metabolic syndrome, and history of ulcer, depressive episodes, hip fracture, or any cancer. Older adults with frailty, co-morbidity, cognitive, and functional impairment had higher odds of taking PIM or getting a PIM prescription in the future (exception: cognitive impairment). Physicians should be especially cautious when prescribing drugs for these patients who are particularly susceptible to adverse reactions.