Translation, cross-cultural adaptation, and validation of the Dutch international hip outcome tool-33 (iHOT-33 NL) in young, physically active individuals with symptomatic hip joint pathology

Abstract

STUDY DESIGN: Prospective cohort. BACKGROUND: The international Hip Outcome Tool-33 (iHOT-33), developed in English, has been shown to be a valid and reliable questionnaire for young, physically active individuals with symptomatic hip joint pathology. OBJECTIVES: To translate and validate the iHOT-33 in Dutch (iHOT-33 NL) in the target population. METHODS: Translation and cross-cultural adaptation of the iHOT-33 were performed following existing guidelines. Young to middle-aged (18-50 years), active (Tegner activity score of 3 or greater) individuals presenting with symptomatic hip joint-related pain (numeric pain-rating score of 1 or greater) in a primary health care/hospital setting were included. The iHOT-33 NL, Hip disability and Osteoarthritis Outcome Score (HOOS), European Quality of Life-5 Dimensions questionnaire (EQ-5D), numeric pain-rating score, and Global Perceived Effect score were completed by 214 patients. RESULTS: The intraclass correlation coefficient for test-retest reliability was 0.92 (95% confidence interval: 0.88, 0.94). Smallest detectable changes at individual and group levels were, respectively, 16.7 and 1.1 points. The Cronbach alpha was .9. Principal-component analysis revealed 4 domains of the iHOT-33 NL. Of the hypotheses used for construct validity, 87% were confirmed. No floor and ceiling effects were detected for the iHOT-33 NL total score. The minimal important change was 10.7 points. CONCLUSION: The iHOT-33 NL is a reliable and valid patient-reported outcome questionnaire for young, physically active individuals with symptomatic hip joint pathology. It can be used in research and clinical settings.