Use of the Scoliosis Research Society Outcomes Instrument to Evaluate Patient Outcome in Untreated Idiopathic Scoliosis Patients in Japan

STUDY DESIGN: This preliminary study evaluates untreated Japanese patients with idiopathic scoliosis using the Scoliosis Research Society Outcomes Instrument (SRS-24). OBJECTIVES: To determine the baseline patient outcome score using the SRS-24 for untreated Japanese scoliosis patients compared with a nonscoliosis group. SUMMARY OF BACKGROUND DATA: The SRS instrument with 24 questions was developed to help evaluate patient-perceived outcomes of idiopathic scoliosis treatment. Evaluation of untreated Japanese idiopathic scoliosis patients using the SRS instrument has not been reported. METHODS: Japanese idiopathic scoliosis patients (n = 141) (mean age, 13.6 years; range, 10-17 years) with a Cobb angle of more than 20 degrees who were not treated with a brace or surgery, were evaluated in comparison with a nonscoliosis group (healthy junior high school students; n = 72) using the SRS-24. The scoliosis group was categorized as mild deformity group with a major curve Cobb angle of less than 30 degrees, moderate deformity group with 30 degrees to 49 degrees, and severe deformity group with more than 50 degrees. The patients were evaluated using section 1 (15 questions) of the SRS-24, which was divided into four domains: total pain, general self-image, general function, and activity. Reliability, as determined by internal consistency, was validated using Cronbach's alpha for these domain scales. RESULTS: The severe deformity group had the lowest scores compared with the other deformity groups and the nonscoliosis group in pain (P < 0.0001) and self-image (P < 0.05) domains. The scores for questions 3 (P < 0.0001) and 5 (P < 0.0001), evaluation of self-image of back appearance, were significantly lower in the scoliosis group than those in the nonscoliosis group. This tendency was more significant in the patients with greater curve magnitude. Scores for questions 14 and 15, evaluation of general self-image, in the scoliosis group were, however, higher than those in the nonscoliosis group. Internal consistency using Cronbach's alpha was 0.57 (pain), 0.27 (general self-image), -0.08 (general function), and 0.15 (overall level of activity). CONCLUSION: Untreated scoliosis patients with severe deformity were inclined to complain of being self-conscious or distressed regarding their back appearance compared with age- and sex-matched control adolescents. The control group was inclined to have, however, a negative general self-image compared with the patients group. Internal consistency using Cronbach's alpha for all domains was considerably low. The baseline of the SRS-24 scores in the Japanese population might differ from that of the Western population because of differences in national culture. Therefore, further study is necessary to clarify the validity of the SRS-24 domains for Japanese patients.