1. Department of Nursing; College of Medicine; National Cheng Kung University; Tainan Taiwan
2. Department of Statistics; College of Management; National Cheng Kung University; Tainan Taiwan
3. College of Health and Human Services; University of New Hampshire; Durham NH
4. Department of Obstetrics and Gynecology; National Cheng Kung University Hospital; College of Medicine; National Cheng Kung University; Tainan Taiwan