Validity and Reliability of Thai Version of the International Knee Documentation Committee Subjective Knee Form
Pisit Lertwanich MD*, Teeranit Praphruetkit MD*, Ekavit Keyurapan MD*, Chanin Lamsam MD*, Teerawat Kulthanan MD*
Affiliation : * Department of Orthopaedic Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok
Background : Self-administered questionnaires have become an important aspect for clinical outcome assess-
ment of knee-related surgery. The International Knee Documentation Committee (IKDC) Subjective Knee
Form is a knee-specific questionnaire that is widely used and translated to many languages. The purposes of
the present study were: (1) to translate the questionnaire into Thai; and (2) to assess the validity and
reliability of the Thai version of the International Knee Documentation Committee (IKDC) Subjective Knee
Form.
Material and Method: The IKDC Subjective Knee Form was translated into Thai using forward-backward
translation protocol. Afterward, reliability and validity were tested. The responses of 55 consecutive patients
on two questionnaires, the Thai IKDC Subjective Knee Form and the Short Form-36, were used. The validity
was tested by correlating the scores from both questionnaires. The reliability was adopted by measuring the
test-retest reliability and internal consistency.
Results : The Thai IKDC Subjective Knee Form showed good correlations with the physical functioning and
bodily pain domains of the SF-36 (Pearson’s correlation coefficient = 0.75 and 0.76 respectively). The reliability
proved excellent with an intra-class correlation coefficient of 0.92 for test-retest. The internal consistency was
strong (Cronbach alpha = 0.92).
Conclusion : The Thai version of IKDC Subjective Knee Form showed good value to retain the characteristic
of the original version. In addition, it was a reliable evaluation instrument for patients with knee-related
problems.
Keywords : International Knee Documentation Committee (IKDC), Validity, Reliability, Short Form 36 general health outcome (SF-36), Questionnaire
