1 School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan; Research Center of Sleep Medicine, School of Medicine, Taipei Medical University, Taipei, Taiwan.
2 Department of Public Health, Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: yukangtu@ntu.edu.tw.