Fig. 1From: A comparison of CPAP and CPAPFLEX in the treatment of obstructive sleep apnea in World Trade Center responders: study protocol for a randomized controlled trialProtocol flow chart. Simplified illustration of the protocol for all participants. CPAP, continuous positive airway pressure; CPAPFlex, continuous positive airway pressure with reduced pressure during expiration OSA, obstructive sleep apneaBack to article page