Cross-cultural adaptation, reliability and validity of the Greek version of the Spinal Appearance Questionnaire (SAQ) in patients with adolescent idiopathic scoliosis

Purpose The Spinal Appearance Questionnaire (SAQ) is a widely validated tool for assessing perceptions of spinal deformity in adolescent idiopathic scoliosis (AIS) patients. This study aimed to develop and validate a Greek version of the SAQ (GR-SAQ). Methods A cross-cultural adaptation of the SAQ following international guidelines was performed. Internal consistency and test-retest reliability were evaluated. Convergent validity was assessed by correlating the GR-SAQ with the Appearance domain of Scoliosis Research Society-22 (SRS-22) and the Cobb angle with the Trunk Shift domain of GR-SAQ. Divergent validity was examined through the relationship between GR-SAQ, patient characteristics, and clinical measures including Cobb angle, DIERS Formetric 4D angle, and scoliometer readings. Results The study included 61 AIS patients (52 females, 13.91 +/- 2.57 years, 25.33 +/- 10.14 degrees Cobb angle). GR-SAQ exhibited good internal consistency (Cronbach's alpha = 0.794) and excellent test-retest reliability (ICC = 0.931, 95%CI: 0.880-0.960). Correlations between GR-SAQ and SRS-22 showed a low-to-moderate negative correlation (r = -0.351, p = 0.006). The Trunk Shift domain moderately correlated with the Cobb Angle (r = 0.393, p = 0.002). Divergent validity analyses did not demonstrate statistical significance (p > 0.05). Conclusion The GR-SAQ is a valid and reliable tool for evaluating spinal deformity perception in Greek AIS patients.