Comparing the ORBIT and HAS-BLED bleeding risk scores in anticoagulated atrial fibrillation patients: a systematic review and meta-analysis

Background: The HAS-BLED and ORBIT scores have been proposed to assess bleeding risk in anticoagulated atrial fibrillation patients. We performed a systematic review and meta-analysis to compare the predictive ability by using these two scores. Materials and Methods: We searched the Cochrane Library, Elsevier and PubMed databases for related studies. Statistical analysis was performed with Revman 5.3 Manager software. We chose the C-statistic to reflect the diagnostic value. Results: In our seven selected studies, the pooled C-statistic of continuous variables for major bleeding was 0.65 (0.60,0.69) for ORBIT and 0.63 (0.60,0.66) for HAS-BLED. Compared with HAS-BLED, more anticoagulated AF patients (88.45% versus 32.59%) and major bleeding events (75.57% versus 25.57%) were categorized as low risk. The ORBIT score had a 1.21, 1.73 and 1.44-fold elevated risk of major bleeding in the low, intermediate and high risk strata respectively. Calibration analysis demonstrated that the ORBIT score under-predicted major bleeding in the low, intermediate, and high risk stratifications, where a odds ratio of 0.64 (0.37-1.10), 0.63 (0.38-1.05) and 0.64 (0.38-1.06), respectively. Conclusions: Compared with HAS-BLED, the ORBIT score does not perform better in predicting major bleeding events in anticoagulated atrial fibrillation patients. More anticoagulated AF patients and major bleeding events were categorized as low risk when using ORBIT.