1. Department of Community, Family and Occupational Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
2. Family Practice Department, Division of Nursing, Srinagarind Hospital, Khon Kaen 40002, Thailand
3. 123 Primary Care Unit, Division of Nursing, Srinagarind Hospital, Khon Kaen 40002, Thailand