technical advisorguideline chairconsultant physicianprofessor of general practiceconsultant diabetologist1 National Institute for Health and Care Excellence, London, UK2 Manchester Mental Health and Social Care Trust, Manchester M21 9UN, UK3 Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK4 University of Oxford, Oxford, UK5 Northern Devon Healthcare NHS Trust, Barnstaple EX31 4JB, UK