Validation of the Korean version of the Spinal Appearance Questionnaire

Abstract

OBJECTIVE:

To evaluate the reliability and validity of an adapted Korean version of the Spinal Appearance Questionnaire (SAQ).

METHODS:

Translation/retranslation of the English version of the SAQ was conducted, and all steps of the cross-cultural adaptation process were performed. The Korean version of the SAQ (K-SAQ) and the previously validated appearance domain of the Korean version of the Scoliosis Research Society-22 Outcomes questionnaire (K-SRS-22) were mailed to 160 patients with adolescent idiopathic scoliosis (AIS). Reliability assessments were conducted using kappa statistics to assess item agreements, and intraclass correlation coefficients (ICC) and Cronbach’s $\alpha$ values were calculated. Convergent validity was evaluated by comparing K-SAQ and K-SRS-22 appearance domain scores and discriminant validity by analyzing relationships between K-SAQ scores and patient characteristics.

RESULTS:

All items of the K-SAQ had kappa values of agreement of $>$ 0.6. The K-SAQ showed excellent test/re-test reliability with an intraclass correlation coefficient of 0.922. Internal consistency of the K-SAQ was found to be very good ( $\alpha$ $=$ 0.883). Convergent validity testing demonstrated a moderate correlation between the K-SAQ and K-SRS-22 ( $r=-$ 451). The correlation between the K-SAQ and major curve magnitude was significant ( $r=$ 0.812). Discriminant validity was confirmed by significant differences in K-SAQ scores and individual K-SAQ domain scores among patients requiring observation, bracing, or surgery.

CONCLUSIONS:

The adapted Korean version of the SAQ showed satisfactory reliability and validity, and thus, is considered suitable for the evaluation of spinal deformity appearance in Korean speaking patients with adolescent idiopathic scoliosis.