Cross-cultural adaptation and psychometric testing of the Spinal Appearance Questionnaire (SAQ).
To evaluate the reliability and validity of simplified Chinese version of the SAQ (SC-SAQ).
The SAQ is widely used to assess the perception of spinal appearance in patients with adolescent idiopathic scoliosis (AIS). However, there is no culturally adapted, reliable, and validated SAQ for mainland China.
The cross-cultural adaptation of the original SAQ was performed following international guidelines. The SC-SAQ was administered concurrently with the simplified Chinese version of the Scoliosis Research Society-22 (SC-SRS-22) questionnaire to 223 patients with AIS. A total of 92 patients were randomly selected to complete the questionnaires again 4 to 7 days after the first completion. Psychometric testing included reliability by internal consistency and test-test reliability, convergent validity by comparing the SC-SAQ with the SC-SRS-22 appearance domain, and discriminant validity by analyzing the relationship between SC-SAQ scores and patients' characteristics.
Internal consistency for the SC-SAQ was satisfactory, with intradomain correlations ranging from r = 0.526 to r = 0.808 (P, 0.0001). The test-retest reliability for the SC-SAQ was excellent with intraclass correlation coefficient of 0.933 (95% confidence interval = 0.903–0.956) and good Bland–Altman agreement. (No systematic bias was found in the Bland–Altman plot.) Convergent validity test demonstrated a moderate correlation between the overall SC-SAQ and SC-SRS-22 appearance domain, with ρ = −0.401 (P, 0.0001). Correlation between the overall SC-SAQ and the major curve magnitude was significant, with r = 0.827 (P, 0.0001). Discriminant validity was confirmed by significant differences of overall SC-SAQ and individual domain scores among the 6 subgroups categorized by the major curve magnitude (P, 0.0001) and among patients requiring exercise, bracing, or surgery (P, 0.0001).
The SC-SAQ showed satisfactory reliability and validity in the evaluation of spinal deformity appearance for patients with AIS in mainland China.
The study aims to develop a simplified Chinese version of the Spinal Appearance Questionnaire (SC-SAQ) and to investigate its psychometric properties. The SC-SAQ was reliable and valid. It was highly correlated to the major curve magnitude and discriminated among patients with idiopathic scoliosis who required exercise, bracing, or surgery.
From the Orthopedic Department of Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China. Xianzhao Wei, Xiaodong Zhu, Yushu Bai, and Dajiang Wu contributed equally to this manuscript.
Address correspondence and reprint requests to Ming Li, MD, Orthopedic Department of Changhai Hospital, Second Military Medical University, No. 168, Changhai Rd., Shanghai, People's Republic of China, 200433; E-mail: firstname.lastname@example.org
Acknowledgment date: July 8, 2011. First revision date: October 29, 2011. Acceptance date: November 1, 2011.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.