[1] UNIV TORONTO,PSORIAT ARTHRITIS CLIN,TORONTO M5S 1A1,ONTARIO,CANADA
[2] UNIV WATERLOO,DEPT STAT,WATERLOO N2L 3G1,ONTARIO,CANADA
[3] UNIV WATERLOO,DEPT ACTUARIAL SCI,WATERLOO N2L 3G1,ONTARIO,CANADA
[4] UNIV WATERLOO,DEPT HLTH STUDIES,WATERLOO N2L 3G1,ONTARIO,CANADA
[5] WOMENS COLL HOSP,TORONTO M5S 1B2,ONTARIO,CANADA