[1] Mahidol Univ, Ramathibodi Hosp, Fac Med, Dept Nursing, Bangkok, Thailand
[2] Yale Univ, Yale Sch Nursing, New Haven, CT USA
[3] Mahidol Univ, Fac Publ Hlth, Dept Biostat, Bangkok, Thailand
[4] Mahidol Univ, Ramathibodi Hosp, Fac Med, Dept Anesthesiol, Bangkok, Thailand