Continuous positive airway pressure (CPAP) reduces symptoms and increases quality of life (QOL) in patients with obstructive sleep apnea (OSA). CPAP may provide benefits other than reduction in sleepiness, however the amount of CPAP required to achieve these improvements is undefined. Medicare requires both subjective improvement and objective evidence of regular CPAP use (>70% of nights for >4 hours/night) for continued coverage, however many patients have persistent symptoms despite good CPAP adherence. Similarly, many patients have improved symptoms with less CPAP use. The purpose of this study was to determine the relationship between CPAP adherence and outcomes.
Prospective study of adult patients newly diagnosed with OSA initiating CPAP therapy. The Epworth Sleepiness Scale (ESS), fatigue analogue scale and Functional Outcomes of Sleep Questionnaire (FOSQ) were measured serially for 6 months after initiation of CPAP. These measures were correlated with the frequency and duration of CPAP use.
154 patients were enrolled. 42.2% patients had regular CPAP use. Among these patients all outcomes improved from baseline. Over the study period ESS improved from 11.2±5.5 to 7.7±4.8 (p=0.001), fatigue improved from 5.3±2.1 to 3.9±2.2 (p=0.002), and FOSQ improved from 14.8±1.3 to 17.7±1.5 (p=0.001). 57.8% of patients in this study had less than regular use. Among these patients 46.7% normalized their ESS and 34.4% normalized their FOSQ by the end of the study period.
CPAP use improved all QOL measures. More CPAP is clearly beneficial in reducing sleepiness and improving QOL. However some patients with less than regular use still experience benefits and despite regular use some patients will continue to experience residual symptoms.
data suggests the current Medicare guidelines may be too stringent thereby preventing some patients from experiencing the benefits of CPAP.
Anita Shah, Grant monies (from industry related sources) This study was funded by an unrestricted grant from Sepracor Inc to the Henry M. Jackson Foundation for the Advancement of Military Medicine; No Product/Research Disclosure Information