title: A brief screening tool for knee pain in primary care. 1. Validity and reliability.
abstract: OBJECTIVE
  To design and test the performance of a new knee pain screening tool (KNEST), both separately and together with a combination of existing questionnaires, which will be used to assess the general health status of knee pain sufferers in primary care.
  
  
  METHODS
  A postal survey of knee pain and disability was sent to a random sample of 240 individuals aged over 55 yr registered with two general practices in North STAFFORDSHIRE: The survey questionnaire consisted of the KNEST; a pain manikin; the Short Form 36 (SF-36); the Hospital Anxiety and Depression Scale (HADS); demographic questions; and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for those who reported knee pain. A second, identical questionnaire was sent 2 weeks later to a random subsample of responders (n=80) to test repeatability.
  
  
  RESULTS
  An 85% baseline response rate was achieved for the first questionnaire. The 12-month prevalence of knee pain identified from baseline responders to the survey was 45%. A response rate of 74% was achieved for the repeatability questionnaire. Each section of the questionnaire was well completed and repeatability was good for nearly all measures (most reliability scores exceeded 0.6). A new core question about knee pain showed good internal reliability, with an agreement score of 91% between baseline and retest assessment, and good construct validity in relation to knee pain identified on the pain manikin (agreement 95%). Good agreement was found between recalled consultation for knee pain in the questionnaire and evidence of consultation for knee pain in general practice records.
  
  
  CONCLUSIONS
  The KNEST appears to be a reliable and valid composite tool for the study of population needs and outcomes of care for people aged over 55 yr with knee pain.
authors.affiliation: Primary Care Sciences Research Centre and. School of Health, Keele University, Keele, Staffordshire ST5 5BG, UK.
authors.forename: C
authors.initials: C
authors.lastname: Jinks
authors.forename: M
authors.initials: M
authors.lastname: Lewis
authors.forename: B N
authors.initials: BN
authors.lastname: Ong
authors.forename: P
authors.initials: P
authors.lastname: Croft
mesh_terms: D004185:Disability Evaluation; D007719:Knee Joint / Q000503:physiopathology*; D008403:Mass Screening / Q000379:methods*; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000503:physiopathology; D010146:Pain / Q000453:epidemiology*; D010342:Patient Acceptance of Health Care; D010865:Pilot Projects; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology