In education group, each subject in the experimental group was taught individually according to investigator's brochure in the outpatient department by researchers. Three months later, participants in the education group received a follow-up phone call in order to clarify any questions related to the brochure. All participants completed posttest at 6-month follow-up.

The control group received the brochure only.

Patient education related Warfarin: each subject in the experimental group was taught individually according to investigator's brochure in the outpatient department (OPD) by researchers. Three months later, participants received a follow-up phone call in order to clarify any questions related to the brochure. The contents of the brochure consisted of: the purpose of taking Warfarin, side effects, adjustments to daily diet, and precautions (i.e. how to take medication safely, interaction between foods and medicine, prevention and checking of signs and symptoms of bleeding). The control group received the brochure after pretest and routine care only in the OPD. All participants completed posttest at 6-month follow-up.

There were six questions and the contents were consistent with investigator's brochure used in investigator's research setting. When participants answered questions correctly, or illustrated at least two correct examples for each item, participants received one point; otherwise, participants received no point. The range of scores was 0-6. The higher the score, the better the patient's knowledge of Warfarin was.

There were six questions. The most commonly cited things patients suffered from while under Warfarin treatment were included. When participants answered "yes", participants received one point; if participants answered "no", participants received no point. The range of scores was 0-6. A higher score indicated a worse life distresses.