[Analysis of iatrogenic risk related to anticholinergic effects using two scales in acute geriatric inpatient unit]

Anticholinergic medications are responsible for most frequent adverse drug effects. Two scales have been elaborated as tools for prescribers: the Anticholinergic Drug Scale (ADS) of Carnahan et al., and the Anticholinergic Risk Scale (ARS) of Rudolph et al. The objective of this study was to analyze the diagnostic performance of both scales for predicting signs related to an anticholinergic effect.

Medical records of 1379 patients aged 75 years or older hospitalized in a geriatric acute care unit between 2002 and 2005 were studied. The analyze was made retrospectively, but data were collected prospectively.

Risk of appearance of total anticholinergic signs (ADS : OR 1,45, CI 95% [1,03-2,03], p=0,037 and ARS : OR 1,98, CI 95% [1,19-3,28] p<0,01) and peripheral signs (ADS: OR 1,66, CI 95% [1,22-2,26], p<0,01 and ARS : OR 1,81, CI 95% [1,19-2,75], p<0,01) increased when score was ≥ 3 with both scales, which wasn't the case for central signs.

Both scales permitted to detect an increased risk of appearance of total and peripheral anticholinergic signs, but not the centrals as delirium. Interest of total anticholinergic burden remains to be demonstrated, especially for delirium risk assessment.