Validation of a Spanish version of the Short Musculoskeletal Function Assessment Questionnaire (SMFA)

Objectives: The purpose of this study was to develop a linguistically appropriate, culturally adapted, and appropriately validated Spanish version of the SMFA (SMFA-Mex). Design: Validation of a survey-based outcome instrument. Setting: Busy state hospital in southern Mexico. Patients/Participants: Consecutive trauma patients with a variety of orthopedic disorders. Intervention: N/A. Main Outcome Measurements: The SMFA-Mex was forward and back translated, administered to orthopedic trauma patients, and compared against the Spanish version of the SF-36s for criterion validity. Statistical analysis included factor analysis, criterion validation with the SF-36, and internal measures of reliability. Results: Factor analysis demonstrated three separate subscale dimensions: 1) upper-extremity dysfunction, 2) lower-extremity dysfunction, and 3) lifestyle alterations. Item analysis showed a high degree of internal consistency for the three subscales (subscale 1, r = 0.95; subscale 2, r = 0.94; subscale 3, r = 0.92). Test-retest reliability at 7 days was 0.93 for the upper-extremity dysfunction subscale, 0.95 for the lower-extremity dysfunction subscale, and 0.92 for the lifestyle-alterations subscale. Construct validity was established by comparison of the Brazilian version of the SF-36. Conclusions: The SMFA-Mex was successfully translated and culturally adapted from the English original. The SMFA-Mex demonstrated adequate scale reliability and validity and yielded three distinct subscales using factor analysis.