Figure 2. Flow diagram of the enrollment, randomization and analysis procedures.

The present study was a double-blind placebo-controlled cross-over study in which an overnight baseline PSG was initially performed to determine eligibility. If deemed eligible, OSA patients were randomized to the allocation order (placebo first or 3 mg of eszopiclone first) and returned for two additional PSG studies at which time the appropriate intervention was administered prior to sleep (visit 1 and visit 2). Refer to the text for further details.