Assessment of reliability and validity of the adapted Persian version of the Spinal Appearance Questionnaire in adolescents with idiopathic scoliosis.

ABSTRACT

PURPOSE: This study investigates the reliability and validity of the adapted Persian version of the Spinal Appearance Questionnaire (P-SAQ). METHODS: The stages of cross-cultural adaptation were conducted according to an internationally accepted guidelines. Reliability of the P-SAQ was measured by evaluating internal consistency and test-retest reproducibility using Cronbach's α and intraclass correlation coefficient (ICC). Validity of the P-SAQ was assessed by factor analysis, and convergent and known-groups validities. Convergent validity was assessed through participant response on the P-SAQ and the revised 22-item Persian version of the Scoliosis Research Society (SRS-22r) questionnaire. Known-groups validity was assessed by comparing the P-SAQ scores according to the patients curve magnitude and treatment type. RESULTS: A total of 106 patients with a diagnosis of adolescent idiopathic scoliosis (AIS) were included. The P-SAQ demonstrated an acceptable internal consistency with a Cronbach's α of 0.77 (range 0.65-0.72). The test-retest reliability was excellent (range ICC 0.85-0.98). There was a correlation between the total score, average scores of the general, curve, rib prominence, kyphosis, and trunk shift subscales of the P-SAQ and subtotal and total scores of the SRS-22r, r = - 0.2 to - 0.4, p < 0.05. The P-SAQ discriminated between patients with differing Cobb angle magnitudes and treatment types (p < 0.01). Factor analysis supported the use of the appearance and expectations items as separate scales for the P-SAQ. CONCLUSION: The P-SAQ is a valid and reliable tool that could be utilized to evaluate the perception of appearance for Persian-speaking AIS patients with different curve magnitude and treatment strategies. LEVEL OF EVIDENCE Level I- diagnostic studies.