Translation and validation of the Dutch version of the International Knee Documentation Committee Subjective Knee Form

Background: For knee-related surgery, there is a great demand for internationally useable subjective scoring systems. Before such measurements can be used, they should be translated and validated for the population they are used on. For the Dutch population, only the Western Ontario and McMaster Universities Osteoarthritis Index and Oxford 12 Questionnaire have been validated. However, these scores can only be used regarding osteoarthritis of the knee. In 2001, the International Knee Documentation Committee presented the Subjective Knee Form, which is a knee-specific rather than a disease-specific questionnaire. Study Design: Cohort study (diagnosis/symptom prevalence); Level of evidence, 2. Methods: The authors describe the translation procedure and validation of the Dutch Subjective Knee Form. After a forward-backward translation protocol, the reliability, validity, and content validity were tested. The responses of 145 consecutive knee patients on 2 questionnaires containing the Short Form-36, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford 12 Questionnaire score, a visual analog scale, and the Dutch International Knee Documentation Committee Subjective Knee Form were used. Reliability was tested by measuring the test-retest reliability and internal consistency. Validity was tested by correlating the questionnaire to the other outcome measurements, and content validity was tested by measuring the floor and ceiling effects. Results: The reliability proved excellent with an intraclass coefficient of 0.96 for test-retest. Internal consistency was strong (Cronbach alpha, .92). The construct, convergent, and divergent validities were good. The content validity was good; no floor or ceiling effect occurred. Conclusion: The validation procedure shows that the Dutch International Knee Documentation Committee Subjective Knee Form is an excellent evaluation instrument for Dutch patients with knee-related injuries.