1 Centre for Mental Health and Safety, Division of Psychology and Mental Health, University of Manchester, Manchester M13 9PL, UK; Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PL, UK; NIHR School for Primary Care, University of Manchester, Manchester M13 9PL, UK. Electronic address: sarah.steeg@manchester.ac.uk.
2 Centre for Mental Health and Safety, Division of Psychology and Mental Health, University of Manchester, Manchester M13 9PL, UK; Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PL, UK; NIHR Greater Manchester Patient Safety Collaboration, University of Manchester, Manchester M13 9PL, UK.
3 Centre for Biostatistics, University of Manchester, Manchester M13 9PL, UK.
4 Centre for Mental Health and Safety, Division of Psychology and Mental Health, University of Manchester, Manchester M13 9PL, UK; Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PL, UK; NIHR Greater Manchester Patient Safety Collaboration, University of Manchester, Manchester M13 9PL, UK; Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK.