Association of anticholinergic drug use with postoperative mortality among patients with hip fracture. A nationwide cohort study.

PURPOSE: Anticholinergic (AC) drugs are associated with various determinantal outcomes. Data regarding the effect of AC drugs on mortality among geriatric hip fracture patients are limited and inconsistent.

METHODS: Using Danish health registries, we identified 31,443 patients aged ≥65 years undergoing hip fracture surgery. AC burden was assessed 90 days before surgery by the Anticholinergic Cognitive Burden (ACB) score and number of AC drugs. Logistic and Cox regression producing odds ratios (OR) and hazard ratios (HR) for 30- and 365- day mortality, adjusting for age, sex, and comorbidities were computed.

RESULTS: AC drugs were redeemed by 42% of patients. The 30-day mortality increased from 7% for patients with ACB score of 0 to 16% for patients with ACB score of ≥5, corresponding to an adjusted OR 2.5 (CI: 2.0-3.1). The equivalent adjusted HR for 365-mortality was 1.9 (CI: 1.6-2.1). Using count of AC drugs as exposure we found a stepwise increase in ORs and HRs with increased number of AC drugs; Compared to non-users, adjusted ORs for 30-days mortality were 1.6 (CI: 1.4-1.7), 1.9 (CI: 1.7-2.1), and 2.3 (CI: 1.9-2.7) for users of 1, 2 and 3+ AC drugs. HRs for 365-day mortality were 1.4 (CI: 1.3-1.5), 1.6 (CI: 1.5-1.7) and 1.8 (CI: 1.7-2.0).

CONCLUSION: Use of AC drugs was associated with increased 30-day and 365-day mortality among older adults with hip fracture. Simply counting the number of AC drugs may be a clinically relevant and easy AC risk assessment tool. Continued effort to reduce AC drug-use is relevant.