Reliability and Validity of the Adapted Spanish Version of the Early-onset Scoliosis-24 Questionnaire

Abstract

STUDY DESIGN: Translation and validation of the Early Onset Scoliosis-24 Questionnaire (EOSQ-24). OBJECTIVE: To cross-culturally adapt the American English version of the EOSQ-24 into Spanish language, and to assess its reliability and discriminative validity. SUMMARY OF BACKGROUND DATA: Treatment of early-onset scoliosis (EOS) seeks to improve natural history and health-related quality of life in children, but radiographic parameters are insufficient to evaluate the severity and efficacy of treatment in these patients. EOSQ-24 was developed to assess the health-related quality of life of EOS children; however, it has not been transculturally adapted and validated for Spanish subjects. METHODS: Translation and cross-cultural adaptation of the original EOSQ-24 was performed according to published guidelines by an expert committee. The Spanish version of the EOSQ-24 was applied to 44 EOS patients. Reliability was assessed by internal consistency using Cronbach α, item-total correlations, and inter-item correlations. Data quality was assessed by mean, median, percentage of missing data, and ceiling and floor effects. For discriminative validity, comparisons between categorical variables were made by using non-parametric (Kruskal-Wallis and/or Mann Whitney U) tests, and Spearman correlation coefficients were used for continuous variables. RESULTS: In our study, all items and domains showed very good global internal consistencies (Cronbach α 0.897 and 0.836, respectively). Corrected item-total correlations were good for all domains (>0.3). Two of 24 items showed low corrected item-total correlations (r = 0.179 and r = 0.254), but Cronbach α did not increase when these items were removed. Inter-item correlations were acceptable (>0.2). EOSQ-24 was found capable to discriminate patients with different curves severity (P = 0.001), diagnosis (P = 0.006), and ambulatory status (P = 0.053). CONCLUSION: The Spanish version of the EOSQ-24 is reliable and a valid tool for the psychometric assessment of children with EOS, and can be applied in routine clinical practice and for research purposes. LEVEL OF EVIDENCE: 2.