Cross-cultural adaptation, and validation of the Turkish version of the Nonarthritic Hip Score

Objective: The aim of this study was to translate and cross-culturally adapt the Nonarthritic Hip Score (NAHS) into Turkish and determine the validity and reliability of the translated version in physically active patients with hip pain. Methods Sixty young to middle-aged and physically active patients (34 women and 26 men; mean age=35 years; age range: 18-40 years) with hip pain were included in the study. The original version of the NAHS was first translated into Turkish and back-translated into English by two bilingual translators each. The back-translated version was compared with the initial English version by a committee of the four translators. The Turkish version was then tested with 15 patients with hip pain and 15 healthy individuals. The participants were asked whether they had difficulties in understanding the questions. Subsequently, the questionnaire was accepted for use in the study population. Test-retest reliability and internal consistency were assessed using Intraclass Correlation Coefficient (ICC) and Cronbach's alpha, respectively. The construct validity was determined via the Pearson correlation coefficient between the NAHS and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), modified Harris Hip Score (mHHS), and Short Form-12 (SF-12). Floor and ceiling effects were analyzed. Exploratory factor analysis (EPA) and confirmatory factor analysis (CFA) were performed to test construct validity. Results: An ICC of 0.994 and Cronbach's alpha value of 0.908 were obtained; thus, the Turkish version of the NAHS was reliable. Neither floor nor ceiling effects (15%) were found in the sub-parameters (83-1.7%) and the total score (1.7%) of the NAHS. The EPA test showed that this questionnaire had four factors. Model fit indices in CFA were chi 2/df=2.23, Tucker-Lewis index=0.90, comparative fit index=0.91, goodness of fit index=0.63, root mean square error of approximation=0.14 (90% CI: 0.12-0.16). The NAHS total score showed an excellent correlation with WOMAC (r=-0.909), mHHS (r=0.850), and SF-12 (r=0.811) scores. Conclusion: The Turkish version of the NAHS is a valid and reliable questionnaire for young and physically active patients with hip pain.