[1] Liverpool John Moores Univ, Publ Hlth Inst, Liverpool, Lancashire, England
[2] Univ Southern Denmark, Res Unit Musculoskeletal Funct & Physiotherapy, Odense, Denmark
[3] Naestved Slagelse Ringsted Hosp, Res Unit PROgrez, Slagelse, Denmark
[4] Univ New South Wales, Natl Drug & Alcohol Res Ctr, Kensington, NSW, Australia
[5] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, Oxford, England
[6] Univ Aberdeen, Inst Appl Hlth Sci, Aberdeen, Scotland
[7] Univ Aberdeen, Med Stat Team, Aberdeen, Scotland
[8] UCL, Hlth Behav Res Ctr, Dept Epidemiol & Publ Hlth, London, England
[9] Univ Aberdeen, Hlth Serv Res Unit, Aberdeen, Scotland
[10] UCL, Ctr Behav Change, London, England
[11] Radboud Univ Nijmegen, Inst Hlth Sci, Med Ctr, IQ Healthcare, Nijmegen, Netherlands