Seasonal and Temporal Patterns of Brace-Wearing Behavior in Adolescent Idiopathic Scoliosis Assessed Using Objective Sensor Data.

Background and Objectives: Brace treatment is a key component of conservative management in adolescent idiopathic scoliosis (AIS), with treatment success strongly depending on patient adherence. While recommended wearing times are well defined, real-life adherence patterns remain insufficiently characterized. In particular, temporal and seasonal variations in brace-wearing behavior under real-world conditions have not yet been comprehensively characterized. Materials and Methods: This retrospective observational study analyzed objectively measured brace-usage data from scoliosis patients treated with temperature sensor-equipped braces. The study focused exclusively on objectively measured brace-wearing behavior; no clinical or radiographic outcome measures were included. Daily adherence time was recorded and aggregated across 6892 monitoring days from 43 patients. Brace wear was defined using a predefined temperature threshold (≥29 °C). Temporal patterns were assessed by analyzing weekday versus weekend differences, seasonal variation, and hourly wear probability. A linear mixed-effects model with patient as a random effect was applied to evaluate the influence of season, day type, and time since treatment initiation. Results: The mean objectively measured daily brace-wearing time was 9.22 h (median 8.67 h), demonstrating substantial variability. Wear time was slightly lower on weekends compared to weekdays (-0.34 h/day, p = 0.026). Seasonal differences in objectively measured brace-wearing time were observed (p < 0.001), with the highest values occurring during summer and the lowest during winter. Mixed-effects modeling confirmed increased wear time in summer (+2.05 h/day, p < 0.001) and reduced wear in winter (-1.27 h/day, p < 0.001) compared to spring. Heatmap analysis revealed pronounced diurnal patterns, with peak usage during nighttime hours (approximately 21:00-06:00) and reduced daytime adherence. A small but significant decline in wear time over the observation period was noted. Conclusions: Objective monitoring demonstrated temporal and seasonal variation in brace-wearing behavior under real-world conditions. Although environmental influences on temperature-based monitoring cannot be excluded, these findings provide valuable insights into adherence patterns and may support individualized patient counseling and future optimization of conservative scoliosis management.