Reliability and validity of a kyphosis-specific spinal appearance questionnaire

Purpose: Hyperkyphosis, including Scheuermann and postural kyphosis, is associated with decreased perceived cosmesis and well being. No patient reported outcome questionnaire specific to kyphosis exists. We sought to assess the internal consistency, test–retest reliability and concurrent validity of a new Kyphosis-specific Spinal Appearance Questionnaire (K-SAQ). Methods: A K-SAQ was developed from a modified SAQ to measure kyphosis-specific aspects of appearance. Patients with hyperkyphosis (ages 10–20 years) curves ≥ 50° completed the K-SAQ and SRS-22R at baseline and the K-SAQ 2 weeks later. Results: 55 patients completed the K-SAQ and SRS-22R. 28 patients completed the K-SAQ 2 weeks later. The K-SAQ total averages showed excellent internal consistency (Cronbach’s α = 0.91) and test–retest reliability (ICC = 0.84). Moderate associations were seen between the SRS-22R subtotal average score and K-SAQ total average score and (r = − 0.62, p < 0.001) and the SRS-22R self-image domain with the K-SAQ total average score (r = − 0.57, p < 0.001). Higher BMI and increased age scored worse on the K-SAQ total average, whereas only higher BMI scored worse on the SRS-22R subtotal average. Conclusion: The K-SAQ is a reliable patient reported outcome measure of kyphosis-specific aspects of appearance.