Patients With Obstructive Sleep Apnea Still Benefit From Suboptimal CPAP Adherence

Patients with obstructive sleep apnea and daytime sleepiness still receive a substantial benefit from suboptimal continuous positive airway pressure adherence.

Patients with obstructive sleep apnea (OSA) and daytime sleepiness still receive substantial benefit from suboptimal continuous positive airway pressure (CPAP) adherence, according 2-week, parallel, double-blind, randomized controlled trial results published in the European Respiratory Journal.

Current guidelines for OSA recommend CPAP therapy as the treatment of choice; however, adherence is often thought to be suboptimal. Researchers from 9 Swiss sleep laboratory centers investigated the effects of suboptimal CPAP usage on objective and subjective sleepiness parameters in patients with moderate to severe OSA with excessive pretreatment daytime sleepiness who had suboptimal CPAP adherence over ≥12 months (mean nightly usage, 3-4 hours).

A total of 57 patients were allocated through minimization to either subtherapeutic CPAP (sham-CPAP) or continuation of CPAP (therapeutic-CPAP) and 52 completed the study (50% in each group). The researchers found that the unadjusted Epworth-Sleepiness Scale (ESS) score increase was 2.4 points (P =.01) in the sham-CPAP group compared with continuing therapeutic CPAP. In addition, the probability of superiority of therapeutic CPAP over sham CPAP was 90.41% for ESS, 90.17% for systolic, and 80.27% for diastolic blood pressure.

According to the researchers, it is important to note that this trial population consisted of a select group of patients with excessive daytime sleepiness and moderate to severe OSA and therefore the conclusions may not be generalizable to other populations with OSA.

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“We conclude, that patients with daytime sleepiness are still getting a substantial benefit from suboptimal CPAP adherence albeit not as much as they might get if they adhered more,” the researchers stated. They added that, “suboptimal CPAP usage between 3 and 4 hours/night in moderate to severe patients with OSA might not be a valid reason to stop treatment or not reimburse treatment at all.” Thus, future studies should consider a wider spectrum of CPAP usage patterns in a variety of patients.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Gaisl T, Rejmer P, Thiel S, et al. Effects of suboptimal adherence of CPAP-therapy on symptoms of obstructive sleep apnea: a randomised, double-blind, controlled trial [published online December 20, 2019]. Eur Respir J. doi:10.1183/13993003.01526-2019