Validation of the Japanese version of the scoliosis research society-30 questionnaire for adult patients with spinal deformity

Background: The Scoliosis Research Society-30 (SRS-30) is a questionnaire that was originally developed from the SRS-22r questionnaire and is used to evaluate adolescent idiopathic scoliosis (AIS). It comprises two sections, with Section 1 containing 22 items related to the SRS-22r questionnaire and 1 item regarding self-image and Section 2 containing 7 items specifically related to postoperative status. The SRS-30 has been also found useful in evaluating spinal disorders or deformity in adults. However, the Japanese version of the SRS-30 (Japanese SRS-30) has been validated for adolescent idiopathic scoliosis, but not for adult spinal deformity (ASD). This study aimed to assess the internal consistency and external validity of the Japanese SRS-30 for ASD. Methods: Of the 30 questions on the SRS-30, 8 questions added from the SRS-22r were translated and back-translated to create the Japanese SRS-30. The Japanese SRS-30 was used to survey patients with ASD who underwent corrective fusion surgery within 1 postoperative year. The internal consistency of the responses was evaluated using Cronbach α coefficient. Additionally, we performed Spearman correlation analysis of the Oswestry Disability Index (ODI) and SRS-22r with the Japanese SRS-30. Results: We included 120 patients (20 males and 100 females; mean age at surgery, 53.3 years). The mean preoperative Cobb angle, sagittal vertical axis, and pelvic incidence minus lumbar lordosis were 36.9°, 81.8 mm, and 24.0°, respectively. The Cronbach α coefficient for the overall SRS-30 was 0.941, indicating high internal consistency. Moreover, the coefficients for each domain were as follows: function/activity, 0.864; pain, 0.783; self-image/appearance, 0.858; mental health, 0.916; and satisfaction, 0.763. The total SRS-30 score was significantly correlated with the total SRS-22r score (r = 0.966, P < 0.001) and ODI (r = −0.752, P < 0.001). The SRS-30 domains showed strong correlations with the corresponding SRS-22r domains, with the r values ranging from 0.878 to 1.000 (all P < 0.001 except mental health). Conclusions: The Japanese SRS-30 demonstrated good internal and external validity. The Japanese SRS-30 can be used to assess health-related quality of life in patients with ASD.