CPAP adherence reduces cardiovascular risk among older adults with obstructive sleep apnea.

Study Objectives: To examine (1) the impact of adherence to continuous positive airway pressure (CPAP) therapy on risk for cardiovascular (CVD) events among a nationally representative sample of older adults with obstructive sleep apnea (OSA), and (2) the heterogeneity of this effect across subgroups defined by race, sex, and socioeconomic status.

Methods: We conducted a retrospective cohort study among Medicare beneficiaries aged ≥ 65 years with OSA (2009-2013). Monthly indicators of CPAP adherence (charges for machines, masks, or supplies) were summed over 25 months to create a CPAP adherence variable. New CVD events (ischemic heart disease, cardiac and peripheral procedures) were modeled as a function of CPAP adherence using generalized estimating equations. Heterogeneity of the effect of CPAP on new CVD events was evaluated based on race, sex, and socioeconomic status.

Results: Among 5024 beneficiaries diagnosed with OSA who initiated CPAP, 1678 (33%) demonstrated new CVD events. Following adjustment for demographic and clinical characteristics, CPAP adherence was associated with reduced risk of new CVD events (hazard ratio 0.95; 95% confidence interval 0.94, 0.96) over 25 months. When analyses were stratified by time since the first CPAP charge, the protective effect remained significant for the 12- and 6-month, but not 3-month, outcome models. No significant differences were observed in the protective effect of CPAP based on race, sex, or socioeconomic status.

Conclusions: In this national study of older adult Medicare beneficiaries with OSA, CPAP adherence was associated with greatly reduced risk for CVD events. This risk reduction was consistent across race, sex, and socioeconomic subgroups.