[1] Radboud Univ Nijmegen, Med Ctr, Sci Inst Qual Healthcare, NL-6500 HB Nijmegen, Netherlands
[2] Maastricht Univ, Sch Primary Care & Publ Hlth, Dept Gen Practice, NL-6200 MD Maastricht, Netherlands
[3] Johns Hopkins Univ, Sch Publ Hlth, Dept Int Hlth, Baltimore, MD 21205 USA
[4] Univ E Anglia, Sch Med Hlth Policy & Practice, Norwich NR4 7TJ, Norfolk, England
[5] Cardiff Univ, Sch Med, Dept Publ Hlth & Primary Care, Cardiff CF14 4XN, S Glam, Wales