[1] Univ Hosp Bristol NHS Fdn Trust, NIHR ARC West, Bristol, Avon, England
[2] Univ Bristol, Bristol Med Sch, Populat Hlth Sci, Bristol, Avon, England
[3] Univ Bristol, Populat Hlth Sci & NIHR Hlth Protect Res Unit Eva, Bristol, Avon, England
[4] Univ Bristol, Populat Hlth Sci & Hlth Econ Bristol, Bristol, Avon, England
[5] Univ Bristol, Populat Hlth Sci & Ctr Acad Primary Care, Bristol, Avon, England
[6] Avon & Wiltshire Mental Hlth Partnership NHS Trus, Blackberry Hill Hosp, Acer Unit, Bristol, Avon, England
[7] Northern Devon Healthcare NHS Trust, Devon Sexual Hlth North Devon, Barnstaple, England