Polypharmacy and associated cumulative anticholinergic burden are important predictors of falls risk.

Abstract

It is evident that polypharmacy among older adults results in increased cumulative anticholinergic exposure and several adverse outcomes. We read with interest and congratulate Hilmer et al. on their multicentre cohort study in Australia, investigating the association between cumulative anticholinergic and sedative medication exposure and adverse outcomes. The authors conclude that potentially inappropriate medications (PIMS) and drug burden index (DBI) are significantly associated with increased risks of fall and delirium.1 We would like to share our experience from the United Kingdom where polypharmacy is a known and growing phenomenon associated with adverse effects in older adults.2 We investigated the potential confounding effects of polypharmacy and cumulative anticholinergic burden (ACB) in older adults hospitalized with fall. We prospectively evaluated 411 consecutive patients aged ≥65 years (mean age 83.8 ± 8.0 years: 40.6% male) admitted acutely to hospital. Pharmacological reconciliation was carried out by hospital pharmacists utilizing the national patient database: NHS Summary Care Record, which contains all regular and acute medication prescriptions. Incidence of polypharmacy (defined as prescription of ≥5 regular oral medications), ACB score (http://www.acbcalc.com/) and Charlson Comorbidity Index (CCI) were recorded and compared between patients admitted with or without fall. We further evaluated the association between polypharmacy, summative ACB score, CCI, age and falls risk. Overall incidence of polypharmacy in our study group was 80.8%, consistent with previous epidemiology studies.3 Polypharmacy in patients admitted without and with fall were 76.3% and 88.0%, respectively. Incidence of ACB score of 0, 1, 2 and ≥3 was 38.7%, 20.9%, 14.6% and 25.8%, respectively. On multivariate analysis, age (OR = 1.030, [1.000; 1.050], P = 0.049), ACB score (OR = 1.150, [1.020; 1.290], P = 0.025), polypharmacy (OR = 2.140, [1.190; 3.870], P = 0.012) but not CCI (OR = 0.920, [0.810; 1.040], P = 0.172) were significantly associated with higher falls rate (Table 1). On linear regression analysis, a patient with an ACB score of 3 compared to a patient with an ACB score of 0 would have a >50% higher chance of falling. We also found that among patients admitted with fall, 29.8% had drug-related orthostatic hypotension, 24.7% had drug-related bradycardia, 37.3% were prescribed centrally acting drugs and 12.0% were taking inappropriate hypoglycaemic agents. Our study complements the findings of Hilmer et al. and other recent studies suggesting cumulative ACB is significantly associated with falls risk in older adults.2, 4, 5 Our data also demonstrated that the presence of polypharmacy and each unit rise in ACB score had a stronger effect on increasing falls risk compared to age and comorbidities. Polypharmacy and ACB are modifiable risk factors, and our findings strongly support deprescribing when possible to prevent falls and improve outcomes in older adults.6, 7 Further studies are required to support the clinical benefits of deprescribing and its feasibility in a clinical setting. None.