Association of Brace-Wearing Time With Changes in Health-Related Quality of Life Assessed by the Scoliosis Japanese Questionnaire-27 in Braced Female Adolescents With Idiopathic Scoliosis: A Multicenter Cohort Study

Background Brace treatment is the only evidence-based effective conservative therapy for adolescent idiopathic scoliosis (AIS). However, the relationship between brace treatment and health-related quality of life (HRQOL), and the extent to which brace-wearing time is associated with HRQOL, remain unclear. This study investigated longitudinal changes in HRQOL, assessed using the Scoliosis Japanese Questionnaire-27 (SJ-27) and their association with daily brace-wearing time. Methods This multicenter observational cohort study included 179 female patients with AIS undergoing brace treatment. Daily brace-wearing time at follow-up (> 1-year after brace initiation) was assessed by questionnaire and categorized using a 12 h/day cutoff (< 12 vs. ≥ 12 h/day). In the overall cohort and in each brace-wearing time group, the major Cobb angle and SJ-27 scores (Pain, Discomfort when wearing clothes, Cognition/psychological distress, Appearance/self-consciousness, Participation/physical activity, and total score) were compared between baseline and follow-up. Multivariate regression analyses were performed to examine the association between brace-wearing time and changes (Δ) in HRQOL as assessed by the SJ-27. Results The mean follow-up duration was 24.7 months. In the overall cohort, the SJ-27 Pain and Discomfort when wearing clothes domain scores worsened, whereas the Cognition/psychological distress and Participation/physical activity domain scores improved; the total SJ-27 score showed no significant change. In analyses stratified by brace-wearing time (< 12 vs. ≥ 12 h/day), neither group showed a significant change in the major Cobb angle from baseline to follow-up. Pain and clothing-related discomfort worsened regardless of wear time, whereas the ≥ 12 h/day group additionally showed deterioration in the Appearance/self-consciousness domain and the total score. In multivariate analysis, ≥ 12 h/day bracing was independently associated with worsening in ΔAppearance (p = 0.017), ΔParticipation (p = 0.036), and ΔTotal score (p = 0.033). Conclusion During brace treatment, pain and clothing-related discomfort worsened, whereas overall HRQOL was largely preserved. Longer daily brace wear (≥ 12 h/day) was independently associated with deterioration in appearance-related self-consciousness, physical activity, and overall HRQOL. These findings suggest that, in braced female patients with AIS, changes in HRQOL should be considered when discussing wear-time targets during follow-up.