[1] Univ Bristol, Med Sch, NIHR Hlth Protect Res Unit Behav Sci & Evaluat, Bristol BS8 2BN, Avon, England
[2] NIHR Appl Res Collaborat ARC West, 9th Floor, Bristol BS1 2NT, Avon, England
[3] Univ Bristol, Bristol Med Sch, Populat Hlth Sci, Bristol BS8 2BN, Avon, England
[4] Sch Educ, 35 Berkeley Sq, Bristol BS8 1JA, Avon, England
[5] Univ Bristol, Bristol Med Sch, Ctr Acad Mental Hlth, Oakfield House, Bristol BS8 2BN, Avon, England
[6] Univ Bath, Dept Pharm & Pharmacol, Bath BA2 7AY, Avon, England
[7] Bristol Drugs Project, 11 Brunswick Sq, Bristol BS2 8PE, Avon, England
[8] Univ Bristol, Bristol Med Sch, Integrat Epidemiol Unit, Oakfield House, Bristol BS8 2BN, Avon, England