Ng, VWS; Siu, C-W; Chiu, PKC; Kng, CPL; Jamieson, E; Wong, ICK; Lam, MPS; (2020) Understanding the barriers to using oral anticoagulants among long-term aspirin users with atrial fibrillation - a qualitative study. BMC Health Services Research , 20 (1) , Article 1084. 10.1186/s12913-020-05947-3.