1. Faculty of Nursing, Chiang Mai University, Chiang Mai, Thailand
2. Youth Family and Community Development Project, Faculty of Nursing, Chiang Mai University, Chiang Mai, Thailand
3. Division of General Internal Medicine, Department of Medicine, Medical School, The University of Texas Health Science Center at Houston, TX, USA
4. Behavioral Science Core, Baylor–UT Houston Center for AIDS Research, Houston, TX, USA