SALT LAKE CITY – Continuous positive airway pressure adherence rates are suboptimal, findings from a study of sleep clinic patients suggest.
Of 528 adults diagnosed with obstructive sleep apnea and followed for a mean of 5 months, 63% had relatively poor adherence (use of less than 4 hours per night), 21% had adequate adherence (use of 4–6 hours per night), and only 16% had optimal adherence (use of more than 6 hours per night). Mean adherence was 3.1 hours per night, Carl Stepnowsky, Ph.D., reported at the annual meeting of the Associated Professional Sleep Societies.
Adherence was specifically defined as use at the prescribed pressure, and was measured by an internal clock. Baseline disease severity correlated with higher levels of adherence.
Patients had a mean age of 59 years, and most had moderate to severe obstructive sleep apnea, with a mean apnea-hypopnea index of 38.8 events per night. Mean change scores (0.68 pounds in weight, -1.6 mm Hg in diastolic blood pressure, and -2.6 mm Hg in systolic blood pressure) were not statistically different from zero, noted Dr. Stepnowsky of the VA San Diego Healthcare System.
The findings are of concern, he said, because suboptimal use of continuous positive airway pressure therapy leads to ineffective treatment and can increase the risk of morbidity and mortality.
A closer look at adherence rates showed that patterns of adherence were established as early as the first night of therapy, suggesting that preexisting factors might explain these patterns. Further studies in large, U.S.-based populations are needed to replicate these findings, as are studies to help identify the factors associated with adherence and to develop tools for improvement, he said.