The counselling process will be delivered as follows: (1) researchers assist patients in signing up and using the telepharmacy application; (2) researchers send the counselling information from the telepharmacy application to the patient's account (the information will be provided as leaflets and 3-5-minute videos to improve the accessibility); (3) the integrated chatbot system forwards any additional questions or concerns of the patients to the counselling pharmacists; and (4) the pharmacists directly address the patient's questions or concerns through phone calls within the shortest possible timeframe.

Measured using Morisky-Green-Levine scale. The levels of adherence are: (1) high (0 point); (2) medium (1-2 points); and (3) low (3-4 points).

Measured using Anticoagulant Knowledge Tool scale that was modified and validated on Vietnamese patients. This includes two sections: (1) general knowledge of oral anticoagulants (16 questions with a maximum score of 21) and (2) specific knowledge of vitamin K antagonists (5 questions with a maximum score of 8, only for patients using vitamin K antagonists). For multiple-choice questions, 1 correct answer earns 1 point, while for short-answer questions, 1 correct answer may result in 1-3 points, depending on the questions. The standardized score will be presented as percentage (based on the maximum score of 21 for direct-acting oral anticoagulant-taking patients or 29 for those using vitamin K antagonists), with the higher score indicating better knowledge.