[1] Univ Aberdeen, Dept Publ Hlth, Epidemiol Grp, Sch Med, Aberdeen AB25 2ZD, Scotland
[2] Paijat Hame Cent Hosp, Joint Author Paijat Hame Social & Hlth Care, Rehabil Ctr, Lahti 15850, Finland
[3] Univ City, Higher Coll Technol, Sharjah, U Arab Emirates
[4] Rheumatism Fdn Hosp, SF-18120 Heinola, Finland
[5] Univ Tampere, Tampere Sch Publ Hlth, FIN-33014 Tampere, Finland
[6] Tampere Univ Hosp, Pediat Res Ctr, FIN-33014 Tampere, Finland
[7] Turku Univ Hosp, Dept Phys & Rehabil Med, FIN-20520 Turku, Finland