[1] Univ Sci & Technol, Trondheim, Norway
[2] Norwegian Inst Publ Hlth, Dept Phys Hlth & Aging, Oslo, Norway
[3] Univ South Carolina, Arnold Sch Publ Hlth, Dept Exercise Sci, Columbia, CA USA
[4] Trondheim Reg & Univ Hosp, St Olavs Hosp, Dept Neurol & Clin Neurophysiol, Trondheim, Norway
[5] Trondheim Reg & Univ Hosp, St Olavs Hosp, Div Psychiat, Trondheim, Norway
[6] Hosp Univ Navarra HUN, Geriatr Unit, Navarrabiomed, Pamplona, Spain
[7] Univ Publ Navarra UPNA, IdiSNA, Pamplona, Spain
[8] Nord Univ, Fac Nursing & Hlth Sci, Levanger, Norway
[9] Haukel & Univ Hosp, Norwegian Competence Ctr Sleep Disorders, Bergen, Norway
[10] Univ Bergen, Dept Global Publ Hlth & Primary Care, Bergen, Norway
[11] Dept Publ Hlth & Nursing, PB 8905, N-7491 Trondheim, Norway