title: Reliability, validity, and responsiveness of four knee outcome scales for athletic patients.
abstract: BACKGROUND
  Many patient-based knee-rating scales are available for the evaluation of athletic patients. However, there is little information on the measurement properties of these instruments and therefore no evidence to support the use of one questionnaire rather than another. The goal of the present study was to determine the reliability, validity, and responsiveness of four knee-rating scales commonly used for the evaluation of athletic patients: the Lysholm scale, the subjective components of the Cincinnati knee-rating system, the American Academy of Orthopaedic Surgeons sports knee-rating scale, and the Activities of Daily Living scale of the Knee Outcome Survey.
  
  
  METHODS
  All patients in the study had a disorder of the knee and were active in sports (a Tegner score of 4 points). Forty-one patients who had a knee disorder that had stabilized and who were not receiving treatment were administered all four questionnaires at baseline and again at a mean of 5.2 days (range, two to fourteen days) later to test reliability. Forty-two patients were administered the scales at baseline and at a minimum of three months after treatment to test responsiveness. The responses of 133 patients at baseline were studied to test construct validity.
  
  
  RESULTS
  The reliability was high for all scales, with the intraclass correlation coefficient ranging from 0.88 to 0.95. As for construct validity, the correlations among the knee scales ranged from 0.70 to 0.85 and those between the knee scales and the physical component scale of the Short Form-36 (SF-36) and the patient and clinician severity ratings ranged from 0.59 to 0.77. Responsiveness, measured with the standardized response mean, ranged from 0.8 for the Cincinnati knee-rating system to 1.1 for the Activities of Daily Living scale.
  
  
  CONCLUSIONS
  All four scales satisfied our criteria for reliability, validity, and responsiveness, and all are acceptable for use in clinical research.
authors.affiliation: Center for Clinical Outcome Research, Hospital for Special Surgery, New York, NY 10021, USA. marxr@hss.edu
authors.forename: R G
authors.initials: RG
authors.lastname: Marx
authors.forename: E C
authors.initials: EC
authors.lastname: Jones
authors.forename: A A
authors.initials: AA
authors.lastname: Allen
authors.forename: D W
authors.initials: DW
authors.lastname: Altchek
authors.forename: S J
authors.initials: SJ
authors.lastname: O'Brien
authors.forename: S A
authors.initials: SA
authors.lastname: Rodeo
authors.forename: R J
authors.initials: RJ
authors.lastname: Williams
authors.forename: R F
authors.initials: RF
authors.lastname: Warren
authors.forename: T L
authors.initials: TL
authors.lastname: Wickiewicz
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis / Q000503:physiopathology; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013177:Sports; D011795:Surveys and Questionnaires; D016896:Treatment Outcome