Introduction Several Studies Have Demonstrated That Patient Compliance with Nasal Continu- Ous Positive Airway Pressure

SEVERAL STUDIES HAVE DEMONSTRATED THAT PATIENT COMPLIANCE WITH NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP), used to treat obstructive sleep apnea (OSA), is suboptimal.1-5 Interestingly, in these studies, a lower CPAP pressure was associated with better patient compliance. Auto-titrating positive airway pressure (APAP) systems were developed to allow for a lower average pressure over the course of a night.6,7 It has been shown that APAP can control obstructive apneas as well as CPAP, and usually at a lower average pressure.8-12 These data lead to the hypothesis that machine use will be greater with APAP; and therefore, symptoms of excessive daytime sleepiness will be improved to a greater extent with APAP than with CPAP. Thus, the purpose of this study was to compare the improvement in daytime sleepiness and the machine use pattern between APAP and CPAP in the same group of OSA patients, using a randomized, cross-over, single-blind design. METHODS