Validation and clinical relevance of a French-Canadian version of the spinal appearance questionnaire in adolescent patients.

STUDY
DESIGN: Prospective validation study of a crosscultural adaptation of the Spinal Appearance Questionnaire (SAQ).
OBJECTIVE: To provide a French-Canadian version of the SAQ. SUMMARY OF BACKGROUND DATA: The SAQ is widely used for the assessment of appearance in adolescent idiopathic scoliosis patients.
METHODS: French translation/back-translation of the Spinal Appearance Questionnaire-French version (SAQ-fv) was done by an expert committee. Its reliability was measured using the intradomain correlation coefficient, concurrent validity by using the Scoliosis Research Society (SRS) Outcomes Questionnaire, and discriminant validity using analysis of variance, on 182 consecutive patients attending a scoliosis clinic.
RESULTS: Intradomain correlations were weak to excellent (ρ = 0.34-0.76, P < 0.01), indicating that the scales' items demonstrated a satisfactory internal coherence. Scores comparison between SAQ-fv items and SRS Outcomes Questionnaire domains showed weak to moderate correlations (ρ = 0.35-0.53, P < 0.01) for the self-image domain, as expected in this test of convergent validity. A clear gradient in SAQ-fv scores according to Cobb angles was found in every domain, and patients' perception of their rib prominence was significantly related to the rib hump measurement, showing good discriminant validity. Body mass index, age, Risser, and gender did not influence the questionnaire scores. Preoperative patients' and parents' scores were significantly more affected when compared with other groups (observation, braced, and postoperative). Distribution of scores in the first section of the questionnaire shows a positive skew toward the wellbeing end of the response scales. However, the other section shows an inversed bell-shape distribution.
CONCLUSION: The SAQ-fv showed satisfactory reliability and validity in French-Canadian adolescents with different severity of idiopathic scoliosis. Spinal deformity appearance evaluation using this tool was found to be independent of patient's general characteristics. In addition, the SAQ-fv is able to discriminate between relevant clinical values, thus providing useful information for the clinical management of adolescent idiopathic scoliosis patients.