Abstract 2339: Predictors of Warfarin Use in Atrial Fibrillation in the United States
Introduction: Warfarin has been shown to be highly efficacious in preventing stroke in patients with atrial fibrillation (AF), yet it is still vastly underused for this purpose in the United States (US).
Objective: To perform a meta-analysis to evaluate the association between prescriber and/or patient characteristics and subsequent prescription of warfarin for stroke prevention in patients with AF.
Methods: Observational studies conducted only in the US using multivariate analysis to determine the relationship between prescriber and/or patient characteristics and the odds of receiving warfarin for stroke prevention in AF were identified from searches in the MEDLINE and EMBASE (1996-October 2010), as well as a manual review of references. Estimates of effect of prescriber and/or patient characteristics from individual studies were pooled to calculate summary odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model.
Results: Twenty-eight studies reporting the results of 33 unique multivariate analyses were identified. Warfarin use across included studies ranged from 9.1%-79.8%, with a median of 49.1%. There was a moderately strong correlation between increased warfarin use and time (r=0.60, p=0.002). Upon meta-analysis, characteristics associated with a statistically significant increase in the odds of warfarin use included history of cerebrovascular accident (OR=1.59, 95%CI 1.15-2.18), congestive heart failure (OR=1.36, 95%CI 1.18-1.57), and male gender (OR=1.12, 95%CI 1.04-1.21). Those associated with a statistically significant reduction in the odds of warfarin use included alcohol or drug abuse (OR=0.62, 95%CI 0.40-0.96), perceived barriers to compliance (OR=0.87, 95%CI 0.76-0.99), contraindication(s) to warfarin (OR=0.81, 95%CI 0.69-0.96), dementia (OR=0.32, 95%CI 0.14-0.75), falls (OR=0.60, 95%CI 0.43-0.85), gastrointestinal hemorrhage (OR=0.47, 95%CI 0.40-0.55), intracranial hemorrhage (OR=0.39, 95%CI 0.28-0.55), hepatic impairment (OR=0.59, 95%CI 0.50-0.70), renal impairment (OR=0.69, 95%CI 0.60-0.80), older compared to younger age (OR=0.57, 95%CI 0.39-0.82) and age per 10-year increase (OR=0.78, 95%CI 0.68-0.90).
Conclusion: Warfarin use appears suboptimal, but has improved somewhat over time. Evidence suggests that the decision to prescribe warfarin for stroke prevention in patients with AF is based upon multiple prescriber and patient characteristics.
- © 2012 by American Heart Association, Inc.