Warfarin reduces
stroke risk in
atrial fibrillation (AF) patients. The quality of
warfarin control, measured by time in therapeutic range (TTR), impacts outcome and adverse events. One tool evaluating risk of adverse events and potential
warfarin control would simplify risk-benefit assessment of
warfarin. Recently, HASBLED was demonstrated effective for this purpose, but this was in well-controlled patients with
deep vein thrombosis. HASBLED as a predictor of
warfarin control has not been validated in other populations including differing indications,
warfarin control levels and ethnicities. The aim of this study was to determine whether HASBLED can predict
warfarin control in patients with AF in Australia and Singapore. Retrospective data were collected for patients receiving
warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate HASBLED at the start and end of the study period. TTR was calculated for each patient, and mean TTR used for analysis to stratified HASBLED scores. Of the 4370 patients, there were 3199 in Australia and 1171 in Singapore with mean TTRs of 82% and 58%, respectively. At the start of the study, a HASBLED score ≥3 predicted significantly lower TTR in Singapore, whilst at the end of the study, this score identified patients with poor control in both Australia and Singapore. A HASBLED score ≥3 in patients treated with
warfarin can differentiate significantly lower TTRs in Australian and Singapore patients with AF. HASBLED may assess bleed risk and
warfarin control, identifying patients at high risk of poor
warfarin outcome requiring additional INR monitoring or alternative anticoagulation.