Why Don't Adolescents Wear Their Brace? A Prospective Study Investigating Psychosocial Characteristics That Predict Scoliosis Brace Wear

Predicting brace holiday eligibility in juvenile idiopathic scoliosis

PURPOSE

The psychological effects of scoliosis bracing can be difficult, and thus clinicians sometimes recommend a brace holiday when the curve corrects to less than 25°. However, the clinical indications for taking a break from the brace before reaching maturity have yet to be described. We hypothesized there would be a relationship between brace holiday eligibility and degree of curve at presentation, change in curve magnitude while bracing, and level of bracing compliance.

METHODS

A retrospective cohort study at a single institution was performed from 2016 to 2022. Objective brace compliance I-button data were collected on patients aged 3-9 years old. Patients with other etiologies besides idiopathic scoliosis before the age of 10 were excluded. Binary logistic regression was performed to determine the effect of significant variables on the likelihood of brace holiday.

RESULTS

Fifty-six patients met inclusion criteria. Of these, 20 were able to get a brace holiday. Patients with higher brace compliance and larger in-brace curve correction were more likely to get a brace holiday (P = 0.015, 0.004). Patients with higher BMIs and larger curves at initial presentation were less likely to get a brace holiday (P = 0.002, 0.014).

CONCLUSION

Compliant brace wearers with good in-brace correction are most likely to be eligible for a brace holiday. While some elements remain immutable, others are modifiable, such as bracing compliance. Understanding how outcomes differ between patients who do and do not take a brace holiday will be crucial to elucidating if the psychological benefit of taking a break from the brace can be justified.

BrAIST-Calc: Prediction of Individualized Benefit From Bracing for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Prospective multicenter study data were used for model derivation and externally validated using retrospective cohort data.

OBJECTIVE

Derive and validate a prognostic model of benefit from bracing for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

The Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST) demonstrated the superiority of bracing over observation to prevent curve progression to the surgical threshold; 42% of untreated subjects had a good outcome, and 28% progressed to the surgical threshold despite bracing, likely due to poor adherence. To avoid over-treatment and to promote patient goal setting and adherence, bracing decisions (who and how much) should be based on physician and patient discussions informed by individual-level data from high-quality predictive models.

MATERIALS AND METHODS

Logistic regression was used to predict curve progression to <45° at skeletal maturity (good prognosis) in 269 BrAIST subjects who were observed or braced. Predictors included age, sex, body mass index, Risser stage, Cobb angle, curve pattern, and treatment characteristics (hours of brace wear and in-brace correction). Internal and external validity were evaluated using jackknifed samples of the BrAIST data set and an independent cohort (n=299) through estimates of discrimination and calibration.

RESULTS

The final model included age, sex, body mass index, Risser stage, Cobb angle, and hours of brace wear per day. The model demonstrated strong discrimination ( c -statistics 0.83-0.87) and calibration in all data sets. Classifying patients as low risk (high probability of a good prognosis) at the probability cut point of 70% resulted in a specificity of 92% and a positive predictive value of 89%.

CONCLUSION

This externally validated model can be used by clinicians and families to make informed, individualized decisions about when and how much to brace to avoid progression to surgery. If widely adopted, this model could decrease overbracing of AIS, improve adherence, and, most importantly, decrease the likelihood of spinal fusion in this population.

Personal and Clinical Determinants of Brace-Wearing Time in Adolescents with Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is a three-dimensional spine and trunk deformity. Bracing is an effective treatment for medium-degree curves. Thermal sensors help monitor patients' adherence (compliance), a critical issue in bracing treatment. Some studies investigated adherence determinants but rarely through sensors or in highly adherent cohorts. We aimed to verify the influence of personal and clinical variables routinely registered by physicians on adherence to brace treatment in a large cohort of consecutive AIS patients from a highly adherent cohort. We performed a cross-sectional study of patients consecutively recruited in the last three years at a tertiary referral institute and treated with braces for one year. To ensure high adherence, for years, we have provided specific support to brace treatment through a series of cognitive-behavioural interventions for patients and parents. We used iButton thermal sensor systematic data collection to precisely analyse the real brace-wearing time. We included 514 adolescents, age 13.8 ± 1.6, with the worst scoliosis curve of 34.5 ± 10.3° Cobb. We found a 95% (95CI 60-101%) adherence to the brace prescription of 21.9 ± 1.7 h per day. Determinants included gender (91% vs. 84%; females vs. males) and age < 14 years (92% vs. 88%). Brace hours prescription, BMI, and all clinical variables (worst curve Cobb degrees, angle of trunk rotation, and TRACE index for aesthetics) did not influence adherence.