2 Paramedic, London Ambulance Service NHS Trust, London.
3 Systematic Reviewer, National Institute for Health and Care Excellence (NICE), Manchester.
4 South West London and St George's Mental Health NHS Trust, London.
5 NIHR Greater Manchester Patient Safety Translational Research Centre, Centre for Mental Health and Safety, University of Manchester, Manchester.
6 Centre for Mental Health and Safety, Manchester Academic Health Sciences Centre, University of Manchester; Greater Manchester Mental Health NHS Foundation Trust; NIHR Greater Manchester Patient Safety Translational Research Centre, University of Manchester, Manchester.