Results of the scoliosis research society instrument for evaluation of surgical outcome in adolescent idiopathic scoliosis - A multicenter study of 244 patients

Study Design. An outcome questionnaire was constructed to evaluate patient satisfaction and performance and to discriminate among patients with adoles cent idiopathic scoliosis. Objectives. To determine reliability and validity in a new quality-of-life instrument for measuring progress among scoliosis patients. Summary of Background Data. Meta-analysis of the surgical treatment of adol escent idiopathic scoliosis determined that a uniform assessment of outcome did not exist. In addition, patient measures of well-being as opposed to p rocess measures (e.g., radiographs) were not consistently reported. This es tablished the need for a standardized questionnaire to assess patient measu res in conjunction with process measures. Methods. The instrument consists of 24 questions divided into seven equally weighted domains as determined by factor analysis: pain, general self-imag e, post operative self-image, general function, overall level of activity, postoperative function, and satisfaction. The questionnaire takes approxima tely 5 minutes to complete and is taken at predetermined time intervals. A total of 244 of patients from three different sites responded to the questi onnaire. Results. The reliability based on internal consistency was confirmed with a Cronbach's alpha coefficient greater than 0.6 for each domain. In addition , acceptable correlation coefficient values greater than 0.68 were obtained for each domain by the test-retest method on normal controls. Similarly, t o establish validity of the questionnaire, responses of normal high school students were compared with that of the patients. Consistent differences we re noted in the domains between the two groups with P < 0.003. The largest differences were in pain (control, 29.96 +/- 0.20; patient, 13.23 +/- 5.55) and general level of activity (control, 14.96 +/- 0.20; patient, 12.16 +/- 3.23). Examination of the relationship between the domains and patient sat isfaction showed that pain correlates with satisfaction to the greatest deg ree (Pearson's correlation co-efficient, r = -0.511; P < 0.001), followed b y self-image(r = 0.412; P < 0.001). Conclusions. This questionnaire addresses patient measures for evaluation o f outcome in adolescent idiopathic scoliosis surgery by examining several d omains. It also allows for dynamic monitoring of scoliosis patients as they become adults. This is a validated instrument with goad reliability measur es.