[1] MONTREAL GEN HOSP,DIV GEN INTERNAL MED,MONTREAL H3G 1A4,QUEBEC,CANADA
[2] MONTREAL GEN HOSP,DIV CLIN EPIDEMIOL,MONTREAL H3G 1A4,QUEBEC,CANADA
[3] MCGILL UNIV,DEPT MED,MONTREAL H3A 2T5,QUEBEC,CANADA
[4] MCGILL UNIV,DEPT EPIDEMIOL & BIOSTAT,MONTREAL H3A 2T5,QUEBEC,CANADA