Brace Treatment Compliance in Patients with Idiopathic Scoliosis

• (a - The Nemours Foundation)

Purpose: Compliance of brace treatment for idiopathic scoliosis has generally been determined from patient or parent interviews; however, the reported hours worn per day are subjective and consequently not accurate. Actual hours worn per day is a key variable in evaluation of the efficacy of brace treatment. The purpose of this study is to evaluate objectively the actual hours worn per day and compliance of brace treatment for patients with idiopathic scoliosis using a compliance monitor.

Methods: The study design was a prospective and blinded study to evaluate compliance with brace treatment. Full institutional review board approval was obtained. Subjects were 56 consecutive patients with idiopathic scoliosis treated with a Wilmington brace, 51 girls and 5 boys. The average age at the beginning of monitoring was 12 years (range, 6-16 years). Inclusion criteria were more than 20 degrees and less than 45 degrees of their Cobb angle before brace treatment. Prescribed regimens were 8, 12, 16 and 23 hours of wear per day depending upon the severity of the scoliosis. Actual hours worn per day was measured using a compliance monitor attached on the brace. The monitor consisted of a data logger and a temperature sensor. Patients were monitored for 316 days on average (range, 20-740 days). Compliance was determined by the percentage of actual hours worn to the prescribed regimen. Accuracy of compliance from reported hours by patients was compared with actual hours worn. Correlations between prescribed regimen, age, magnitude of curvature and compliance were analyzed by the ANOVA, Rho coefficient and dependent t-test.

Results: The overall compliance measured by the monitor was 75%±27% (mean±S.D.), and the frequency distribution was similar to a Gaussian distribution. The compliance determined from reported hours by patients was 85±24% which was significantly higher than that from actual hours measured by the monitor (P=0.13). There was a negative correlation between age and compliance (Rho=-0.30, P=0.025); 10-, 12- and 14-year-old patients had 84%, 77% and 60% compliance on average, respectively. The average actual hours worn per day were 7.5, 8.6, 10.5, and 15.1 hours when prescribed regimens were 8, 12, 16, and 23 hours per day, respectively. Compliance in patients with different prescribed regimens showed no statistical difference (P=0.361). Only four of 13 patients who had a prescribed regimen of 23 hours of brace wear per day wore the brace for 20 hours or more. There was no correlation between the magnitude of curvature and compliance (r=0.02).

Conclusions: This study confirms the need for a compliance monitor to accurately evaluate use and outcome of brace treatment, since patients with idiopathic scoliosis comply with 75% of prescribed regimen on average and report longer hours than actual to a physician. Age affects compliance and has to be considered for prescription of brace wearing hours. Limitations of this study are inclusion of various curve patterns and a visible compliance monitor that may have affected patients compliance.

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