Concordance Between Anticholinergic Burden Scales.

OBJECTIVES

To evaluate concordance of five commonly used anticholinergic scales.

DESIGN

Cross-sectional secondary analysis.

SETTING

Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Community-dwelling adults aged 70 to 79 with baseline medication data from the Health, Aging, and Body Composition Study (N = 3,055).

MEASUREMENTS

Any anticholinergic use, weighted scores, and total standardized daily dosage were calculated using five anticholinergic measures (Anticholinergic Cognitive Burden (ACB) Scale, Anticholinergic Drug Scale (ADS), Anticholinergic Risk Scale (ARS), Drug Burden Index anticholinergic component (DBI-ACh), and Summated Anticholinergic Medications Scale (SAMS)). Concordance was evaluated using kappa statistics and Spearman rank correlations.

RESULTS

Any anticholinergic use in rank order was 51% for the ACB, 43% for the ADS, 29% for the DBI-ACh, 23% for the ARS, and 16% for the SAMS. Kappa statistics for all pairwise use comparisons ranged from 0.33 to 0.68. Similarly, concordance as measured using weighted kappa statistics ranged from 0.54 to 0.70 for the three scales not incorporating dosage (ADS, ARS, ACB). Spearman rank correlation between the DBI-ACh and SAMS was 0.50.

CONCLUSION

Only low to moderate concordance was found between the five anticholinergic scales. Future research is needed to examine how these differences in measurement affect their predictive validity with respect to clinically relevant outcomes, such as cognitive impairment.