[1] Mahidol Univ, Fac Med, Dept Pediat, Ramathibodi Hosp, Bangkok, Thailand
[2] Mahidol Univ, Fac Med, Dept Community Med, Ramathibodi Hosp, 270 Rama VI Rd, Bangkok 10400, Thailand
[3] Khon Kaen Univ, Fac Med, Dept Community Med, Khon Kaen, Thailand
[4] Mahidol Univ, Fac Med, Ramathibodi Sch Nursing, Ramathibodi Hosp, Bangkok, Thailand
[5] Chiang Mai Univ, Fac Publ Hlth, Chiang Mai, Thailand
[6] Prince Songkla Univ, Fac Med, Epidemiol Unit, Hat Yai, Thailand
[7] Chulalongkorn Univ, Coll Publ Hlth Sci, Bangkok, Thailand