Lack of Concordance between Empirical Scores and Physician Assessments of Stroke and Bleeding Risk in Atrial Fibrillation: Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) Registry
Background—Physicians treating patients with atrial fibrillation (AF) must weigh the benefits of anticoagulation in preventing stroke versus the risk of bleeding. While empirical models have been developed to predict such risks, the degree to which these coincide with clinicians' estimates is unclear.
Methods and Results—We examined 10,094 AF patients enrolled in the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF) registry between June, 2010 and August, 2011. Empirical stroke and bleeding risks were assessed using the CHADS2 and ATRIA scores, respectively. Separately, physicians were asked to categorize their patients' stroke and bleeding risks: low- (<3%); intermediate- (3-6%); and high-risk (>6%). Overall, 72% (n=7251) in ORBIT-AF had high-risk CHADS2 scores (≥2). However, only 16% were assessed as high stroke risk by physicians. While 17% (n=1749) had high ATRIA bleeding risk (score ≥5), only 7% (n=719) were considered so by physicians. The associations between empirical and physician-estimated stroke and bleeding risks were low (weighted Kappa 0.1 and 0.11, respectively). Physicians weighed hypertension, heart failure, and diabetes less significantly than empirical models in estimating stroke risk; physicians weighted anemia and dialysis less significantly than empirical models when estimating bleeding risks. Anticoagulation use was highest among patients with high stroke risk, assessed by either empirical model or physician estimates. In contrast, physician and empirical estimates of bleeding had limited impact on treatment choice.
Conclusions—There is little agreement between provider-assessed risk and empirical scores in AF. These differences may explain, in part, current divergence of anticoagulation treatment decisions from guideline recommendations.
Clinical Trial Registration Information—clinicaltrials.gov Identifier: NCT01165710.
- Received January 6, 2014.
- Revision received February 19, 2014.
- Accepted March 10, 2014.