Comparative effectiveness of oral appliances and continuous positive airway pressure: a prospective non-randomized study using a non-inferiority framework.

Abstract

Continuous positive airway pressure (CPAP) is the first‑line treatment for moderate-to-severe obstructive sleep apnea (OSA), while mandibular advancement devices (MAD) are an established alternative for CPAP-intolerant patients. Differences in efficacy and adherence may affect overall clinical effectiveness. This prospective non-randomized study (First Line Obstructive Sleep Apnea Treatment (FLOSAT)) evaluated the clinical effectiveness of MAD therapy as first-line treatment option compared to second-line CPAP therapy. Moderate-to-severe OSA patients received three months of MAD therapy, followed by a wash-out period and three months of CPAP therapy. The primary outcome was mean disease alleviation (MDA), a measure combining efficacy and adherence, analyzed using a modified intention-to-treat approach. Ninety-four patients (86% male, age: 52±12 years, body mass index: 28·1±3·4 kg/m2) were included. The averaged individual MDA was 49·9±26·1% with MAD and 49·1±34·5% with CPAP, demonstrating non-inferiority of MAD compared to CPAP (p = 0·4). The apnea/hypopnea index (AHI) decreased significantly from 24·2(18·1; 32·3)/h at baseline to 8·4(5·4; 12·9)/h with MAD and to 4·1(2·2; 11·5)/h with CPAP (both p < 0·001). Nightly adherence was significantly higher with MAD (6·7(5·2;7·3) hours/night) than with CPAP (5·4(2·0;6·5); p < 0·05). In this study, 51% of patients preferred MAD compared to 42% for CPAP. MAD therapy achieved good efficacy and high adherence, resulting in non-inferior effectiveness compared to CPAP. However, the sequential, non-randomized design limits interpretation because treatment effects cannot be separated from potential order or period effects. Furthermore, MDA has not been validated against patient-important outcomes and therefore does not establish clinical non-inferiority.