Background: Elderly patients with multiple chronic conditions are closely linked to polymedication, a condition that is also highly associated with the presence of adverse effects, such as those observed by anticholinergic activity. Anticholinergic burden is defined in a very variable way and is described inconsistently using different scores and providing different interpretations of the risk of suffering from anticholinergic adverse effects.
Objective: The objective is to analyse the anticholinergic risk exposure in elderly complex chronic patients.
Methods: A observational multicentre study was performed for a cohort of complex chronic patients over 65 years who received treatment with at least one drug with anticholinergic activity. Anticholinergic exposure was assessed using ten scales included in the Anticholinergic Burden Calculator.
Results: 473 patients were recruited, being 67.7% with excessive polypharmacy. 80 was the total number of anticholinergic drugs with any scale, with a median of 2 drugs with anticholinergic activity per patient (IQR=2). Three scales evaluated more than 70% of the patients (Chew: 79.1%; Drug Burden Index (DBI): 77.8%; Anticholinergic Cognitive Burden (ACB): 75.9%). The percentage of different drugs with anticholinergic properties evaluated ranged from 13.8% (Anticholinergic Burden Classification (ABC)) to 57.5% (DBI) and anticholinergic drugs prescriptions oscillated from 14% (Anticholinergic Risk Scale (ARS)) to 53.3% (DBI). 71.1% of patients were at risk (moderate and high risk) according to DBI vs. 9.7% by ARS at the opposite side. Important differences of anticholinergic risk in patients with excessive polypharmacy were in ACB, ABC and DBI scales.
Conclusion: This study has highlighted clear differences between the scales used. DBI seems to be the scale that identifies a higher number of elderly chronic complex patients at risk of developing anticholinergic adverse effects.