Reliability and validity of a novel quality of life questionnaire for female patients with adolescent idiopathic scoliosis: Scoliosis Japanese Questionnaire-27: a multicenter, cross-sectional study

BACKGROUND: A progressive deformity associated with adolescent idiopathic scoliosis (AIS) negatively affects a patient’s health-related quality of life (HRQOL). Although the Scoliosis Research Society-22 (SRS-22) is the standard measurement tool for assessing HRQOL in patients with AIS, it is partially suboptimal for evaluating HRQOL in Japanese patients with AIS because of cultural differences. The purpose of this study was to develop a novel patient-reported outcome measure for Japanese female patients with AIS and to evaluate the reliability and validity of this questionnaire in comparison with the SRS-22 tool. METHODS: We developed 27 questions based on the psychosocial problems in the daily life of young female patients with AIS in Japan, the Scoliosis Japanese Questionnaire-27 (SJ-27). To evaluate its reliability, the internal consistency was assessed using Cronbach’s alpha coefficient. Concurrent validity was evaluated using Spearman’s correlation coefficient between the SJ-27 and the SRS-22. To investigate the construct validity of the SJ-27, the correlation between the SJ-27 questions was assessed using Akaike’s information criterion (AIC). RESULTS: We analyzed 384 female patients with AIS. Cronbach’s alpha coefficients were 0.914 and 0.829 for the SJ-27 and the SRS-22, respectively. Spearman’s correlation coefficient between the SJ-27 and the SRS-22 was 0.692 (p < 0.001). The AIC analysis indicated that the SJ-27 items are divided into five domains, indicating that the SJ-27 covered a wide range of health-related problems among female patients with AIS. CONCLUSIONS: The results suggest that the SJ-27 is a reliable and valid patient-reported outcome measure for evaluating HRQOL in female patients with AIS in Japan.