Validity of the Spanish version of the Scoliosis Research Society-22 (SRS-22) Patient Questionnaire

Study Design. A cross-sectional multicenter study was performed to validate the Spanish version of the Scoliosis Research Society-22 (SRS-22) Patient Questionnaire. Objectives. To determine the construct validity and convergent validity of the instrument. Methods. The Spanish version of the SRS-22 was given to 175 patients with scoliosis ( mean age, 19 years old and 86% women). A subgroup of 31 patients also received the Quality of Life for Spine Deformities Profile (QLSDP). Construct validity was studied by factor analysis. Discriminant validity was assessed analyzing the relation between SRS-22 scores and the variables of deformity severity. Convergent validity as related to the QLSDP was studied with a multitrait-multimethod matrix analysis. Results. Factor analysis offered a solution of four factors coherent with the dimensions of the original instrument. SRS-22 scores were worse in older patients ( r = - 0.34); patients using analgesics demonstrated lower scores ( P < 0.001). Patients treated with a brace had a poorer self-image and were less satisfied with their treatment ( P < 0.001) than the other treatment groups. Angular improvement of the curves was associated with better self-image scores ( r = 0.34). The SRS-22 and QLSDP demonstrated high correlation coefficients in the convergent validity tests ( r = 0.84). Conclusion. The Spanish version of the SRS-22 is valid. It has a factorial structure similar to that of the original questionnaire. Moreover, it relates to known severity characteristics of the disease, distinguishes among scoliosis patient groups, and shows concordant values with another valid instrument for measuring self- perceived health.