title: Threshold Assessment Grid (TAG): the development of a valid and brief scale to assess the severity of mental illness.
abstract: BACKGROUND
  Lack of consensus about the meaning of severe mental illness makes it difficult to prioritise the severely mentally ill for specialist mental health care. The goal of this study was to develop a valid and brief assessment of severity of mental illness.
  
  
  METHODS
  Six search workshops (n = 57) using consensus techniques developed a draft assessment acceptable to users, carers, practitioners and policy makers. A two-round Delphi consultation (n = 58) was held to identify consensus on this instrument.
  
  
  RESULTS
  Search workshops agreed seven domains relevant to identifying the severely mentally ill: intentional and unintentional self-harm, risk from and to others, and survival, psychological, and social needs and disabilities. The Delphi consultation indicated at least agreement with all aspects in both rounds.
  
  
  CONCLUSIONS
  The Threshold Assessment Grid (TAG) is a brief method of identifying the severely mentally ill, which has adequate face, concurrent, construct and content validity.
authors.affiliation: Section of Community Psychiatry (PRiSM), Institute of Psychiatry, London, UK. m.slade@iop.kcl.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Slade
authors.forename: R
authors.initials: R
authors.lastname: Powell
authors.forename: A
authors.initials: A
authors.lastname: Rosen
authors.forename: G
authors.initials: G
authors.lastname: Strathdee
mesh_terms: D003697:Delphi Technique; D004739:England; D006801:Humans; D001523:Mental Disorders / Q000175:diagnosis*; D011594:Psychometrics / Q000379:methods*; D015203:Reproducibility of Results; D012720:Severity of Illness Index