Adequate health literacy is associated with adherence to continuous positive airway pressure in adults with obstructive sleep apnea

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is a chronic disease with significant health implications and adequate adherence to continuous positive airway pressure (CPAP) is essential for effective treatment. In many chronic diseases, health literacy has been found to predict treatment adherence and outcomes. In this study, the aim was to determine the health literacy of a sleep clinic population and evaluate the association between health literacy and CPAP adherence. METHODS: A prospective cohort study was undertaken, recruiting 104 consecutive patients with a variety of sleep diagnoses. The Short Form Rapid Estimate of Adult Literacy in Medicine (REALM-SF), a validated questionnaire, was administered to measure health literacy. In a sub-group of 91 patients prescribed CPAP for OSA, CPAP usage was measured, with adequate usage defined as greater than 4 h/night CPAP therapy. RESULTS: Seventy-one percent of the sleep clinic cohort was found to have adequate health literacy, as measured by the REALM-SF. In those prescribed CPAP for OSA, inadequate health literacy was associated with a twofold increased risk for inadequate CPAP usage (adjusted odds ratio [OR] 2.9, 95% CI: 1.1 to 8.22, p = 0.045). There was a 1.7 h/night difference in median CPAP usage comparing those with adequate to inadequate health literacy (4.6 h vs. 6.3 h/night). CONCLUSIONS: The majority of this sleep disorders cohort had adequate health literacy as measured by the REALM-SF questionnaire. However, inadequate health literacy appears to be an independent predictor of treatment adherence and may represent a modifiable risk factor of poor treatment outcomes in OSA.