[1] Univ Laval, Res Ctr, Populat Hlth & Optimal Hlth Practices Unit, St Sacrement Hosp,CHU Quebec, 1050 Chemin St Foy, Quebec City, PQ G1S 4L8, Canada
[2] Univ Laval, Dept Social & Prevent Med, Fac Med, 1050 Ave Med, Quebec City, PQ G1V 0A6, Canada
[3] Univ Laval, Rehabil Dept, Fac Med, 1050 Ave Med, Quebec City, PQ G1V 0A6, Canada
[4] Univ Montreal, Sch Publ Hlth, Dept Social & Prevent Med, 7101 Ave Parc, Montreal, PQ H3N 1X9, Canada
[5] London Sch Hyg & Trop Med, Fac Epidemiol & Populat Hlth, Keppel St, London WC1E 7HT, England
[6] CHU Ste Justine, Res Ctr, 3175 Cote Ste Catherine, Montreal, PQ H3T 1C5, Canada