The measurement properties of the IKDC-subjective knee form

PURPOSE: 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. LEVEL OF EVIDENCE: Systematic review, Level III.