[1] Paragon, Asia Sleep Ctr, 290 Orchard Rd,Unit 18-04, Singapore 238859, Singapore
[2] Univ Rey Juan Carlos, Hosp Univ Fuenlabrada, Madrid, Spain
[3] Clin Univ Navarra, Navarra, Spain
[4] Hosp Quiron Salud Marbella & Campo Gibraltar, Cadiz, Spain
[5] Natl Univ Singapore, Sch Med, Biostat Unit, Singapore, Singapore
[6] Western Univ, London, ON, Canada