Background: Although CPAP is a highly efficacious treatment for obstructive sleep apnea (OSA), low adherence presents a significant challenge for sleep medicine clinicians. The present study aimed to evaluate the relationship between insomnia symptoms and CPAP use. We hypothesized that pre-treatment insomnia complaints would be associated with poorer CPAP adherence at clinical follow-up.
Methods: This was a retrospective chart review of 232 patients (56.5% men, mean age=53.6+/-12.4years) newly diagnosed with OSA (mean AHI=41.8+/-27.7) and prescribed CPAP in the Johns Hopkins Sleep Disorder Center. Difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening were measured via three self-report items. CPAP use was measured via objective electronic monitoring cards.
Results: Thirty-seven percent of the sample reported at least one frequent insomnia complaint, with 23.7% reporting difficulty maintaining sleep, 20.6% reporting early morning awakening and 16.6% reporting difficulty initiating sleep. After controlling for age and gender, sleep maintenance insomnia displayed a statistically significant negative relationship with average nightly minutes of CPAP use (p<.05) as well as adherence status as defined by the Centers for Medicaid and Medicare Services (p<.02).
Conclusions: To our knowledge, these are the first empirical data to document that insomnia can be a risk factor for poorer CPAP adherence. Identifying and reducing insomnia complaints among patients prescribed CPAP may be a straightforward and cost-effective way to increase CPAP adherence.
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