Development of the Italian version of the revised scoliosis research society-22 patient questionnaire, SRS-22r-I: Cross-cultural adaptation, factor analysis, reliability, and validity

Study Design. Evaluation of the psychometric properties of a translated and culturally adapted questionnaire. Objective. Translating, culturally adapting, and validating the Italian version of the revised Scoliosis Research Society-22 Patient Questionnaire (SRS-22r-I) in order to allow its use with Italian-speaking patients with adolescent idiopathic scoliosis (AIS). Summary Of Background Data. Increasing attention is being given to health-related quality of life measures as a means of adding information about the evaluation of AIS. A translated form of the revised SRS-22 has never been validated in Italian patients with AIS. Methods. The development of the SRS-22 questionnaire involved its translation and back-translation, a final review by an Expert Committee, and testing of the prefinal version to establish its correspondence to the original English version. Psychometric testing included factor analysis, reliability by internal consistency (Cronbach alpha) and test-retest repeatability (Intraclass Coefficient Correlation), and concurrent validity (Pearson correlation) by comparing the SRS-22r-I domains with the Short-Form Health Survey (SF-36) subscales. Results. It took 4 months to develop a shared version of the SRS-22r-I, which proved to be satisfactorily acceptable when administered to 223 subjects with AIS. Factor analysis indicated a 4-factor solution (54% of the explained variance), and the questionnaire had an acceptable level of internal consistency (α = 0.77) and a high level of test-retest reliability (intraclass correlation coefficient = 0.957). In terms of concurrent validity, the correlations with the related Short-Form-36 subscales were moderate to good in the case of the Pain and Mental Health domains, and moderate in the case of the Function and Self-Image domains. Conclusion. The Italian translation of the SRS-22r has a good factorial structure and psychometric properties, and replicates the results of existing English versions of the questionnaire. Its use for research purposes can therefore be recommended.