[1] Univ Calgary, Ctr Hlth & Policy Studies, Calgary, AB T2N 4N1, Canada
[2] British Columbia Res Inst Childrens & Womens Hlth, Ctr Healthcare Innovat & Improvement, Vancouver, BC V6H 3V4, Canada
[3] Univ British Columbia, Dept Hlth Care & Epidemiol, Vancouver, BC V6T 1W5, Canada
[4] Newcastle Univ, Ctr Hlth Serv Res, Sch Populat & Hlth Sci, Newcastle Upon Tyne NE2 4AA, Tyne & Wear, England
[5] Newcastle Univ, Business Sch Econ, Newcastle Upon Tyne NE2 4AA, Tyne & Wear, England