STUDY DESIGN: Prospective, sequential enrollment. OBJECTIVE: We report the development and testing of the Spinal Appearance Questionnaire (SAQ) for reliability, validity, and responsiveness in patients with
idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: The SAQ was designed to measure patients' and their parents'
perception of their spinal deformity's appearance using standardized drawings and questions. This study was designed to test the instrument's
psychometric properties. METHODS: The SAQ was administered as a
test-retest to
idiopathic scoliosis patients and parents for reliability and initial validity assessment (Group I). It was then administered to patients before
surgery and 1 year after
surgery (Group II) for responsiveness and further validity testing. Finally, both the SAQ and SRS instruments were administered to adolescent
idiopathic patients before
surgery and 1 year after
surgery (Group III) for comparison of the 2 instruments. RESULTS: Group I: The individual scale items had good to excellent reliability (
Spearman's rho, 0.57-0.99) and high internal scale consistency (
Cronbach's alpha >0.7). The
mean scale scores differentiated between curves greater than 30 degrees and lesser curves (P < 0.01).
Surgery improved scores compared with those with "
surgery recommended." Group II: The domains
correlated with clinical and
radiographic aspects of the
deformity before
surgery. All of the domains showed significant difference after
surgery (P < 0.0001) and large
effect size for all domains except for the patient
chest domain. Group III: Both the SAQ and the SRS instruments had significant improvement in all of their domains except for the SRS Activity scale. The
relative efficiency of the SAQ domains to the SRS appearance domain (the most responsive SRS domain) was greater for 5 SAQ domains. CONCLUSION: The SAQ is reliable, responsive to curve improvement, and shows strong evidence of validity. It provides more detail than the SRS in the appearance domain, and provides explanation of spinal deformity's concerns and improvements.
