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 multifaceted 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.
Melanie K. Means, Ph.D., reported on 33 Veterans Affairs outpatients with OSA and subtherapeutic CPAP use referred to her as a behavioral sleep psychologist. She determined that claustrophobic symptoms were a primary contributor to CPAP nonadherence in all 33 patients. She then developed a brief exposure-based behavioral treatment intervention aimed at reducing CPAP-related anxiety. The therapy was provided in a mean of 2.5 individual sessions. It involved a series of graded steps and homework assignments to help patients become more comfortable with CPAP.
She reported on 10 patients who completed the behavioral intervention. Five others dropped out of behavioral therapy or stopped CPAP altogether. Six remain in behavioral therapy. Twelve patients were excluded from the study because of a lack of objective CPAP usage data.
During a mean of 79 days of follow-up, CPAP usage improved in 9 of 10 patients. Pre-treatment, patients used their CPAP machine an average of one night in three. At follow-up they averaged two nights in three on CPAP. Their average hours of use per night used increased from 2.3 to 4.3. Averaged over all nights, CPAP use climbed from 0.8 hours to 3.2 hours per night, according to Dr. Means of Duke University, Durham, N.C.
In a separate study, Dr. Aloia and coworkers found that psychologic measures of behavior change constructs derived from the transtheoretical model and social cognitive theory accounted for up to 37% of the variance in average nightly CPAP use over the course of 6 months in a cohort of 101 OSA patients. In contrast, demographic and disease severity measures collectively accounted for less than 10% of the variance.
Assessment at 1 week of measures of readiness to adhere to regular CPAP use were strongly predictive of long-term adherence, as were measures of self-efficacy obtained at 3 months.
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