The purpose of this review is to conduct a systematic review and meta-analysis comparing the effects of continuous positive airway pressure (CPAP) with a mandibular advancement device (MAD) in improving the quality of life (sleepiness, cognitive, and functional outcomes) in patients diagnosed with obstructive sleep apnea (OSA). Authors identified randomized, placebo-controlled studies from MEDLINE through PubMed, Web of Science, and the Cochrane Library. Studies were assessed for inclusion and exclusion criteria, as well as risk of bias. Initial search yielded 240 unduplicated references, which the authors reduced to 12 relevant studies. Patients with CPAP therapy showed no statistically significant difference in the post-treatment quality of life measured with the SF-36 mental health component (p = .994), or the SF-36 physical functioning component (p = .827). There was no significant improvement in neither Functional Outcomes of Sleep Questionnaire (p = .788) nor cognitive performance (p = .395) compared to patients treated with oral appliances. However, the meta-analyses' overall results showed a significant improvement in the post-treatment apnea-hypopnea index (AHI) in favor of CPAP therapy as compared with the oral appliance group (p < .001). Meta-analyses showed unclear results for sleepiness with no significant differences in average post-treatment Epworth Sleepiness Scale [ESS] (p = .203), but significant differences in change in ESS from baseline favorable to CPAP treatment (p = .047). Further studies are needed. Compliance with treatment was 1.1 h per night significantly lower with CPAP than MAD (p = .004), which could explain why though efficacy (AHI) is better with CPAP, no significant results are shown for quality of life, cognitive, and functional outcomes. Though CPAP is significantly more efficient in reducing AHI (moderate quality of evidence), it has a significantly lower compliance resulting in no differences with MAD in quality of life, cognitive, or functional outcomes. Sleep medicine professionals should monitor treatment compliance and offer patients non-compliant with CPAP an oral appliance for treatment of OSA.
Keywords: Apnea–hypopnea index; Continuous positive airway pressure; Functional outcomes; Mandibular advancement device; Obstructive sleep apnea; Quality of life.