Higher baseline Epworth Sleepiness Scale scores were significantly associated with greater early CPAP adherence, with each 1-point increase predicting 7.4% higher odds of being in a greater adherence category, while AHI, BMI, and sex were not significant predictors.
Higher baseline ESS scores were significantly associated with greater 30-day CPAP adherence.
Each 1-point increase in ESS score predicted 7.4% higher odds of being in a greater CPAP adherence category in ordinal logistic regression.
Age modestly but significantly predicted CPAP adherence, while AHI, BMI, and sex were not significant predictors.
Patients with severe daytime sleepiness had the highest rates of excellent CPAP adherence (>90%).
The study design was retrospective and observational, precluding causal inference between ESS scores and CPAP adherence.
This research suggests that how sleepy a patient feels during the day — measured by a simple questionnaire called the Epworth Sleepiness Scale (ESS) — is a meaningful predictor of whether they will stick with CPAP therapy in the first month of treatment. Among 400 adults newly prescribed CPAP for obstructive sleep apnea, those who reported higher levels of daytime sleepiness before starting therapy were more likely to use their CPAP machines consistently over the first 30 days. Patients with the most severe daytime sleepiness had the highest rates of excellent adherence. Notably, the more objective measure of sleep apnea severity — the Apnea-Hypopnea Index (AHI), which counts breathing disruptions per hour — did not predict adherence, nor did body weight or sex. This matters because CPAP therapy is highly effective for sleep apnea but only works if patients actually use it, and adherence is a well-known challenge. The finding that subjective symptom burden (feeling sleepy) predicts compliance better than objective disease severity suggests that patients who are more bothered by their symptoms may be more motivated to continue treatment. Age was also a modest positive predictor, meaning older patients tended to adhere slightly better. This research suggests that routinely measuring daytime sleepiness with the ESS before starting CPAP could help clinicians identify patients who may be at higher risk of poor adherence — particularly those with low ESS scores who may not feel particularly symptomatic — so that extra support or motivational strategies can be offered early. Because this was a retrospective study, it cannot prove that sleepiness causes better adherence, and future prospective research would be needed to confirm and build on these findings.
Baki Z, Alameri M, Singhi S. (2026). Association between Epworth Sleepiness Scores and CPAP compliance in patients with obstructive sleep apnea.. Respiratory medicine. https://doi.org/10.1016/j.rmed.2026.108673