An alternative to a randomized control design for assessing the efficacy and effectiveness of bracing in AIS

Abstract

Current randomized controlled trials (RCTs) for assessing the efficacy of bracing in patients with adolescent idiopathic scoliosis (AIS) suffer from poor recruitment. Additionally, patients who consent for randomization may be a highly selected group of individuals who have no preference on treatment; thus may limit the assessment of effectiveness. Therefore, we aimed to determine the feasibility of an alternative study design, “the comprehensive cohort study” that can overcome the concerns of conventional RCTs. AIS patients aged ≥10 years, had Risser sign between 0-II, and had a Cobb angle of 25° to <30° or 20° to <25° with 5° deterioration over the past 4 months were invited to join a RCT. Those who declined were given an option to stay in the study, but choose whether they wish to be braced or observed. A randomization schedule was generated for all patients whether or not they joined the RCT; thus patients who made their own choice may also fit with the randomized choices. For those without brace but had ≥6° curve progression or reached 30° were considered failures, and braces were offered. Patients were followed every 4 months. Over 1 year, there were 87 eligible patients, 68 (78%) patients with mean age of 12.5 years consented to participate with a median follow-up of 57 weeks. Of which, 19 (28%) patients accepted randomization with respectively 13 and 6 patients allotted to brace and observation. For others who declined randomization, 18 (37%) chose brace and 28 (57%) patients had their choice of treatment the same as that on the randomization schedule. This Comprehensive Cohort Study design has the potential to improve the rate of recruitment such that both efficacy and effectiveness of bracing in AIS can be assessed. Our preliminary study showed that it can be feasibly conducted with less recruitment burden.