[1] McMaster Univ, Hlth Sci Ctr, Ctr Hlth Econ & Policy Anal, Hamilton, ON L8N 3Z5, Canada
[2] McMaster Univ, Inst Work & Hlth, Hamilton, ON L8N 3Z5, Canada
[3] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8N 3Z5, Canada
[4] Inst Clin Evaluat Sci Ontario, Toronto, ON, Canada
[5] Univ Toronto, Dept Hlth Adm, Toronto, ON M5S 1A1, Canada
[6] Univ Toronto, Wellesley Hosp, Res Inst, Div Clin Epidemiol, Toronto, ON M4Y 1J3, Canada
[7] Fred Hutchinson Canc Res Ctr, Canc Prevent Res Program, Seattle, WA 98104 USA
[8] Univ Washington, Dept Hlth Serv, Seattle, WA 98195 USA
[9] Univ Washington, Dept Med, Seattle, WA 98195 USA