DENVER -- Continuous positive airway pressure is widely viewed as the treatment of choice for obstructive sleep apnea. When used correctly, it results in multiple benefits, including salutary changes in cognitive function, quality of life, blood pressure, and daytime sleepiness.
There's just one problem. Patient adherence with this nonpharmacologic therapy is, in a word: lousy.
At the annual meeting of the Associated Professional Sleep Societies, investigators described a variety of creative methods aimed at improving compliance with CPAP, ranging from a brief behavioral therapy to equipment refinements to psychologic profiling to assess patient readiness to change. None, however, succeeded in boosting nightly use of CPAP above the 6-hour minimum that sleep disorder specialists deem necessary to achieve optimal clinical results.
"Optimizing adherence with OSA [obstructive sleep apnea] treatment may require a multi-faceted strategy," concluded Mark S. Aloia, Ph.D., of Brown University, Providence, R.I.
He reported on 148 consecutive patients with moderate to severe OSA. The first 66 were placed on conventional CPAP. The next 82 in this nonrandomized study received CPAP machines equipped with C-Flex technology. C-Flex, developed by Respironics Inc., delivers positive air pressure variably in response to a patient's inhalation/exhalation pattern. The hypothesis was that C-Flex would improve adherence by reducing CPAP-users' common complaints of difficulty exhaling, air leak around the mask, and pressure intolerance. The same home health care company was used for all participants in order to maintain consistency.
Adherence data were gathered at 1 week and 1, 3, and 6 months. The good news was the C-Flex group did use their machines more hours per night than conventional CPAP users. Indeed, at 6 months' follow-up, they were three times as likely as CPAP users to be averaging 6 hours per night of PAP.
The bad news was the C-Flex group still averaged only 4.5 hours per night of PAP--well below the optimal 6 hours. Conventional CPAP users averaged a mere 3.2 hours.