Reliability and validity of simplified Chinese version of the Italian spine youth quality of life questionnaire in adolescents with idiopathic scoliosis

Background The Italian Spine Youth Quality of Life (ISYQOL) questionnaire is used to evaluate health-related quality of life in adolescents with Idiopathic Scoliosis. The study aimed to undertake the process of cultural adaptation of the ISYQOL questionnaire into Simplified Chinese. Methods Translate from Italian into Simplified Chinese. It involved 138 adolescents whose Cobb angle ranged between 20 and 40 degrees, 50 wearing the brace and 88 not wearing the brace. Statistical analysis calculated the reliability, floor effects, and ceiling effects of the ISYQOL. After that, construct validity was measured by analyzing the ISYQOL relationship Scoliosis Research Society-22 patient Questionnaire (SRS-22). Results There were no floor or ceiling effects in the ISYQOL questionnaire. Cronbach's alpha coefficient evaluated for Internal consistency was 0.75 in the no-treated group and 0.88 in the brace-treated group. Intraclass correlation coefficients assessed with the use of the test-retest method were 0.72 in the no-treated group and 0.80 in the brace-treated group. A strong relationship exists between the ISYQOL measure and SRS-22 scores (rho = 0.62; p < 0.01), reflecting the high validity of the questionnaires. Both ISYQOL and SRS-22 scores showed no statistical difference between groups wearing and not wearing the brace (p > 0.05). Conclusions Trans-cultural validation in Chinses language showed the reliability and validity of the ISYQOL.