PURPOSEThere is a need to balance the benefits and risks associated with strong anticholinergic medications in older adults, particularly among those with frailty and cognitive impairment. This study explored the international prevalence of strong anticholinergic medication use in residents of nursing homes with and without cognitive impairment and frailty.METHODSSecondary, cross-sectional analyses of data from 5,800 residents of 106 nursing homes in Australia, China, Czech Republic, England, Finland, France, Germany, Israel, Italy, Japan, Netherlands, and Spain were conducted. Strong anticholinergic medications were defined as medications with a score of 2 or 3 on the Anticholinergic Cognitive Burden scale. Dementia or cognitive impairment was defined as a documented diagnosis or using a validated scale. Frailty was defined using the FRAIL-NH scale as 0-2 (non-frail), 3-6 (frail) and 7-14 (most-frail). Data were analyzed using descriptive statistics.RESULTSOverall, 17.4 % (n = 1010) residents used ≥1 strong anticholinergic medication, ranging from 1.3 % (n = 2) in China to 27.1 % (n = 147) in Italy. The most prevalent strong anticholinergics were quetiapine (n = 290, 5.0 % of all residents), olanzapine (132, 2.3 %), carbamazepine (102, 1.8 %), paroxetine (88, 1.5 %) and amitriptyline (87, 1.5 %). Prevalence was higher among residents with cognitive impairment (n = 602, 17.9 %) compared to those without (n = 408, 16.8 %), and among residents who were most frail (n = 553, 17.9 %) compared to those who were frail (n = 286, 16.5 %) or non-frail (n = 171, 17.5 %).CONCLUSIONSOne in six residents who were most frail and living with cognitive impairment used a strong anticholinergic. However, there was a 20-fold variation in prevalence across the 12 countries. Targeted deprescribing interventions may reduce potentially avoidable medication-harm.