title: The measurement properties of the IKDC-subjective knee form.
abstract: OBJECTIVE
  To evaluate the methodological quality of studies reporting on the measurement properties of the International Knee Documentation Committee subjective knee form (IKDC-SKF) and to evaluate their results following the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) guidelines.
  
  
  METHODS
  Systematic search of articles published about the measurement properties of the IKDC-SKF, review of the studies' methodological quality, and synthesis of the results using the COSMIN guidelines.
  
  
  RESULTS
  Twenty-six studies were identified and reviewed. There was strong evidence for good internal consistency, test-retest reliability, and responsiveness. There was moderate evidence for good content and structural validity. With the SF36 as a gold standard, the level of evidence for criterion validity was indeterminate. There was conflicting evidence for hypothesis testing and not enough evidence to evaluate measurement error and cross-cultural validity. There were no floor or ceiling effects.
  
  
  CONCLUSIONS
  This review shows that the IKDC-SKF is a measurement instrument with good internal consistency, test-retest reliability, content and structural validity, and responsiveness and interpretability (no floor and ceiling effects). Further evaluation of measurement error, minimal important change, and hypotheses testing is recommended. The IKDC-SKF seems to be useful as a general instrument for all kinds of knee injuries, which might facilitate its clinical use in situations in which time is a factor.
  
  
  METHODS
  Systematic review, Level III.
authors.affiliation: Division of Physiotherapy, Department of Medical and Health Sciences, Linköping University, 581 83, Linköping, Sweden.
authors.forename: Hanna Tigerstrand
authors.initials: HT
authors.lastname: Grevnerts
authors.affiliation: Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Terwee
authors.affiliation: Division of Physiotherapy, Department of Medical and Health Sciences, Linköping University, 581 83, Linköping, Sweden. joanna.kvist@liu.se.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kvist
mesh_terms: D006304:Health Status; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis*; D015203:Reproducibility of Results
keywords: COSMIN; Knee injury; Outcome; Questionnaire