Higher CPAP Adherence Linked With Lower Mortality Risk in OSA

Each additional hour per night of continuous positive airway pressure (CPAP) use was associated with a 13% reduction in all-cause mortality risk among adults with obstructive sleep apnea (OSA), according to a late-breaking abstract presented at the European Respiratory Society (ERS) Congress 2026, held September 5-9 in Barcelona, Spain.¹

The French national database analysis of more than 31,000 patients also found a dose-response association between CPAP use and major adverse cardiovascular events (MACE), with significantly lower MACE risk at 4 or more hours per night.

Randomized Trials Have Not Shown Cardiovascular Benefit

Whether CPAP reduces cardiovascular events and mortality in OSA remains controversial, the investigators wrote. Randomized trials have not demonstrated a cardiovascular benefit. In the SAVE trial (NCT00738179), CPAP did not significantly reduce cardiovascular events among patients with moderate to severe OSA and established cardiovascular disease, and mean adherence in the CPAP group was 3.3 hours per night.²

SAVE lead investigator R. Doug McEvoy, MD, said the trial may not have achieved the level of CPAP use needed to modify cardiovascular risk.³

Study Tracked Objective CPAP Use Across 31,764 Patients

Investigators linked de-identified data from the French national health insurance database, the Système National des Données de Santé (SNDS), with objective telemonitoring data from cloud-connected CPAP devices.¹ The cohort included adults who initiated CPAP between January 2018 and December 2020. OSA and MACE were identified using diagnostic codes.

The primary outcome was all-cause mortality. The researchers used Cox proportional hazards models and treated CPAP adherence as a time-dependent exposure, meaning each patient's adherence level was updated monthly over follow-up. Adherence was analyzed both as a continuous measure and in categories of nightly use.

Mortality Risk Fell With Each Additional Hour of Use

A total of 31,764 patients were included in the analysis. The median age was 61 years, and 65.3% of patients were men. Deaths were uncommon overall: over a median follow-up of 491 days, 360 patients (1.1%) died.

Each additional hour of nightly CPAP use was associated with lower all-cause mortality risk (hazard ratio [HR], 0.87; 95% CI, 0.84-0.91). Compared with patients using CPAP less than 2 hours per night, lower mortality risk was observed among those using the device:

• 2 to less than 4 hours per night (HR, 0.54; 95% CI, 0.37-0.80)
• 4 to less than 5 hours per night (HR, 0.36; 95% CI, 0.23-0.56)

Similar dose-response associations were observed for MACE, with significantly lower risk at 4 or more hours per night.

“In this large real-world cohort, higher CPAP adherence was associated with dose-dependent reductions in all-cause mortality and MACE,” the authors concluded, adding that the findings support the clinical benefit of CPAP therapy in OSA, particularly for reducing mortality.

Findings Raise Questions About Medicare Adherence Thresholds

Medicare conditions continued CPAP coverage on documented use of at least 4 hours per night on 70% of nights during a consecutive 30-day period within the first 3 months of therapy.⁴ The study measured average nightly use rather than the percentage-of-nights metric Medicare applies.¹ Even so, the lower mortality risk observed at 2 to less than 4 hours per night raises questions about how adherence thresholds relate to outcomes.

The analysis also relied on objective usage data transmitted from cloud-connected devices rather than self-reported adherence.

Observational Design Limits Causal Conclusions

Because the analysis was observational, it cannot establish that CPAP use caused the reductions in mortality or MACE. A known limitation of adherence studies also applies: patients who consistently use therapy may differ from less adherent patients in health behaviors and other characteristics not fully captured in claims data. Median follow-up was relatively short, at less than 18 months. The abstract did not report HRs for use of 5 or more hours per night or specific estimates for MACE.

The results are based on a conference abstract, and full methods and adjusted covariates were not available.

References

1. Pepin J, Malhotra A, Cistulli P, et al. Dose-response relationship between continuous positive airway pressure therapy usage and all-cause mortality and major adverse cardiovascular events in obstructive sleep apnoea: a French national database analysis. Presented at: ERS Congress 2026; September 5-9, 2026; Barcelona, Spain.
2. McEvoy RD, Antic NA, Heeley E, et al. CPAP for prevention of cardiovascular events in obstructive sleep apnea. N Engl J Med. 2016;375(10):919-931. doi:10.1056/NEJMoa1606599
3. Neale T. Treating sleep apnea fails to boost outcomes in patients with CVD: SAVE trial. TCTMD. August 28, 2016. Accessed September 16, 2026. https://www.tctmd.com/news/treating-sleep-apnea-fails-boost-outcomes-patients-cvd-save-trial
4. Local coverage determination: positive airway pressure (PAP) devices for the treatment of obstructive sleep apnea (L33718). CMS. Accessed September 16, 2026. https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?LCDId=33718