The burden of psychotropic and anticholinergic medicines use in care homes: population-based analysis in 147 care homes

Background: Older people living in care-homes are particularly vulnerable to adverse effects of psychotropic and anticholinergic drugs. Methods: Anonymised dispensed prescription data from all 4,478 residents aged ≥ 60 years in 147 care-homes in two Scottish health boards were analysed. Psychotropic medicines examined were antipsychotics, antidepressants, hypnotic/anxiolytics, opioids and gabapentinoids. Anticholinergic burden was measured using the modified anticholinergic risk scale (mARS). Variation between care-homes and associations with individual and care-home characteristics were examined using multilevel logistic regression. Results: 63.5% of residents were prescribed at least one psychotropic drug, and 27.0% two or more, most commonly antidepressants (41.6%), opioids (20.3%), hypnotic/anxiolytics (16.9%) and antipsychotics (16.7%). 48.1% were prescribed an anticholinergic drug, and 12.1% had high anticholinergic burden (mARS ≥ 3). Variation between care-homes was high for antipsychotics (intra-cluster correlation coefficient [ICC] 8.2%) and hypnotics/anxiolytics (ICC = 7.3%), and moderate for antidepressants (ICC = 4.7%) and anticholinergics (ICC = 2.8%). Prescribing of all drugs was lower in the oldest old. People with dementia were more likely to be prescribed antipsychotics (adjusted OR = 1.45, 95%CI 1.23-1.71) but less likely to be prescribed anticholinergics (aOR = 0.61, 95%CI 0.51-0.74). Prescribing of antipsychotics was higher in Tayside (aOR = 1.52, 95%CI 1.20-1.92), whereas prescribing of antidepressants (particularly tricyclic-related) was lower (aOR = 0.66, 95%CI 0.56-0.79). There was no association with care-home regulator quality scores. Conclusion: Care-home residents have high psychotropic and anticholinergic burden, with considerable variation between care-homes that is not related to existing measures of quality of care. Research to better understand variation between care-homes and the interaction with local prescribing cultures is needed.