Purpose: The Knee Injury Osteoarthritis Outcome Score (KOOS) questionnaire is one of the frequently used outcome scores in pediatric studies. However, a recent study demonstrated that the pediatric population had a limited understanding of some of its questions. Therefore, the KOOS-Child questionnaire was developed specifically for this population. Our team produced a French adaptation based on the English version. The objective of the current study was to validate the French adaptation of the KOOS-Child questionnaire.
Methods: After ethic board approval, the questionnaire was translated from English to French by two French speaking orthopedic surgeons. Following consensus, the translated version was retranslated to English by a professional translator. A group of experts compared the original and back translated version and decided on a final adapted questionnaire version. Ninety-nine 8-16 year-old patients were prospectively recruited from our pediatric orthopedic surgery clinic. Twenty-one control participants and 78 patients suffering from knee pain were recruited. The participants were asked to answer the translated French version of the KOOS-Child questionnaire and two validated French pediatric quality of life surveys.
Results: Statistical analysis demonstrated no statistically significant demographic difference between the control population and the patients suffering from a knee pathology. The mean for the five different domains of the KOOS-Child questionnaire showed statistical differences (p < 0.001) between the two groups. Construct validity was demonstrated through testing of previously validated hypothesis of correlation. Internal consistency was also confirmed in injured patients.
Conclusions: In conclusion, the current study results demonstrate good to excellent internal consistency, good construct validity and inconclusive discriminant capacity of the French adaptation of the KOOS-Child questionnaire.
Level of evidence: II.
Keywords: Cross cultural adaptation; French; KOOS-child; Knee Injury Osteoarthritis Outcome Score; Patient health questionnaire; Pediatric orthopaedics; Validation study.