The reported CPAP adherence has varied considerably across studies and across populations, with mixed data about differ- ences in adherence related to differences in CPAP mode (eg, autotitrating versus fixed pressure) or humidification use.742 746 Cognitive-behavioral interventions appear to improve CPAP Several studies have sought to identify predic- tors of CPAP adherence, and results have varied across stud- ies. In general, however, patients who are most symptomatic (eg, excessive daytime sleepiness) are most likely to adhere to treatment in the long term.745 A CPAP use study among 1155 patients with sleep apnea found that 68% were continuing to use the CPAP after 5 years of follow-up.748 Patients with sleep apnea often have concomitant stroke risk factors, including hypertension, AF, diabetes mellitus, obesity, and hyperlipidemia, and several studies have dem- onstrated the importance of adjusting for these factors when examining the relationship between sleep apnea and risk of Given the robust relationship between sleep apnea numerous studies have specifically examined the degree to which CPAP treatment is associated with improvements in BP. Several meta-analyses suggest that the difference in SBP that can be expected with CPAP ranges from a decrease of 1.4 to 7.2 mmHg,736,752 754 with most of the estimates closer to the lower end of this range. Despite being highly prevalent, as many as 70% to 80% of patients with sleep apnea are neither diagnosed nor treated.755 The American Academy of Sleep Medicine730 advocates screening high-risk patients for symptoms of sleep apnea. High-risk populations include those with risk factors for stroke (eg, AF, refractory hypertension) and patients with stroke. 