[1] McGill Univ, Dept Epidemiol Biostat & Occupat Hlth, 1020 Pine Ave West, Montreal, PQ, Canada
[2] McGill Univ, Dept Sociol, 855 Sherbrooke St West, Montreal, PQ, Canada
[3] Bur Hlth Informat, Level 11 Sage Bldg,67 Albert Ave, Chatswood, NSW, Australia
[4] Univ New South Wales, Ctr Primary Hlth Care & Equity, Level 3,AGSM Bldg, Sydney, NSW, Australia
[5] McGill Univ, Inst Hlth & Social Policy, 1130 Pine Ave West, Montreal, PQ, Canada