title: Development of a condition-specific quality of life measure for patients with dentofacial deformity: I. Reliability of the instrument.
abstract: The assessment of quality of life is becoming increasingly important in clinical research. Its importance in dentistry has been realised only relatively recently. Health-related quality of life is concerned with the aspects of quality of life that relate specifically to an individual's health. This may be measured using two groups of instruments: (i) generic measures, which provide a summary of health-related quality of life and sometimes generate a single index measure of health or (ii) condition-specific measures, which focus on a particular condition, disease, population or problem and are potentially more responsive to small, but clinically important, changes in health.
  
  
  OBJECTIVE
  The aim of this study was to develop a condition-specific quality of life measure for those patients with severe dentofacial deformity who were requesting orthognathic treatment and to assess the reliability of this instrument.
  
  
  METHODS
  Instrument content was derived through a literature review and interviews with clinicians and patients. The resulting instrument was tested for internal consistency and test-retest reliability.
  
  
  CONCLUSIONS
  The instrument was found to divide into four clinically meaningful domains. Internal consistency and test-retest reliability were good. Patient acceptance of the questionnaire was also encouraging.
authors.affiliation: Department of Orthodontics, Eastman Dental Institute, University College London, UK. s.cunningham@eastman.ucl.ac.uk
authors.forename: S J
authors.initials: SJ
authors.lastname: Cunningham
authors.forename: A M
authors.initials: AM
authors.lastname: Garratt
authors.forename: N P
authors.initials: NP
authors.lastname: Hunt
mesh_terms: D006301:Health Services Needs and Demand; D006302:Health Services Research / Q000379:methods; D006801:Humans; D019767:Maxillofacial Abnormalities / Q000523:psychology*; D011788:Quality of Life; D015203:Reproducibility of Results; D012647:Self-Assessment; D011795:Surveys and Questionnaires