Reliability of Spanish version of the SRS-22 questionnaire for idiopathic scoliosis

Abstract

Purpose of study: The SRS-22 questionnaire is a specific instrument to measure health-related quality of life in patients with idiopathic scoliosis. It consists of 22 questions corresponding to five scales: pain, function/activity, self-image, mental health and satisfaction with treatment. Previous studies have shown the reliability and validity of the original English version. Further dissemination of the questionnaire needs transcultural adaptation to other prevalent languages. The purpose of the present study is to evaluate internal consistency and reproducibility of the Spanish version of the SRS-22 questionnaire.Methods used: The Spanish version was developed from the original English questionnaire by following a process of translation-retrotranslation and expert consensus. The Spanish form was administered to 175 patients with idiopathic scoliosis, 152 women and 23 men, with a mean age (± SD) of 19.2 ± 7.9 years. Mean magnitudes of the thoracic and lumbar curves were 28.8 ± 14.8 degrees and 28.1 ± 10.4 degrees, respectively. Eighty-five patients were treated surgically and 90 nonoperatively (45 orthosis and 45 observation only). One week after the first session, a group of 30 patients filled out a second set of questionnaires to determine test-retest reproducibility. Internal consistency was evaluated with Cronbach's alpha coefficient and reproducibility with the intraclass correlation coefficient (ICC). Discriminant validity was studied with bivariate analysis, correlating scale scores with age, magnitude of the curves and correction with treatment.of findings: The following are the average scores for the scales (5 being the best and 1 the worst): function/activity 4.21±0.6; pain 4.37±0.7; self-image 3.87±0.6; mental health 4.04±0.7 and satisfaction 4.37±0.7. Cronbach's alpha coefficient of the whole questionnaire was 0.89, and the ICC was 0.96. Global score correlated with age (p<.0001) and magnitude of the curve (p=.0001). Improvement with treatment correlated with satisfaction (p=.0001) and self-image (p=.0001).Relationship between findings and existing knowledge: The score distribution, internal consistency and test-retest reproducibility are similar to the original English version.Overall significance of findings: The Spanish version of the SRS-22 questionnaire has metric attributes similar to the original. Reproducibility, internal consistency and discriminant validity confirm the usefulness of the questionnaire for measuring quality of life in patients with idiopathic scoliosis.Disclosures: No disclosures.Conflict of interest: No conflicts.