[1] UNIV BRITISH COLUMBIA,DEPT HLTH CARE & EPIDEMIOL,VANCOUVER V6T 1Z6,BC,CANADA
[2] CANADIAN INST ADV RES,TORONTO,ONTARIO,CANADA
[3] UNIV BRITISH COLUMBIA,DIV HLTH SERV RES & DEV,HLTH POLICY RES UNIT,VANCOUVER V6T 1W5,BC,CANADA
[4] UNIV BRITISH COLUMBIA,DEPT ECON,VANCOUVER V6T 1W5,BC,CANADA
[5] UNIV BRITISH COLUMBIA,DIV OCCUPAT HLTH,VANCOUVER V6T 1W5,BC,CANADA
[6] MCMASTER UNIV,CTR HLTH ECON & POLICY ANAL,DEPT CLIN EPIDEMIOL & BIOSTAT,HAMILTON L8S 4L8,ONTARIO,CANADA