[1] Univ Minnesota, Sch Med, Ctr Adolescent Nursing, Sch Nursing, Minneapolis, MN 55455 USA
[2] Univ Minnesota, Sch Med, Healthy Youth Dev Prevent Res Ctr, Dept Pediat, Minneapolis, MN 55455 USA
[3] WHO, Dept Child & Adolescent Hlth & Dev, CH-1211 Geneva, Switzerland
[4] United Nat Populat Fund, Amman, Jordan