Double blind parallel trial of Continuous Positive Airway Pressure versus CFLEX-a form of CPAP with exhalation pressure reduction: Effects on objective compliance, reaction time and objective alertness in patients with obstructive sleep apnoea

INTERVENTION: Continuous positive airway pressure (CPAP‐ control ) versus C‐FLEX ‐a form of CPAP with exhalation pressure reduction (intervention). The subjects will use the treatment over a 3 month period each time they sleep. CONDITION: Obstructive sleep apnoea PRIMARY OUTCOME: Objective compliance in average hours per night SECONDARY OUTCOME: Patient preference by questionnaire at the end of the trial INCLUSION CRITERIA: Adults (males and females) with polysomnographically confirmed obstructive sleep apnoea with an apnoea hypopnoea index of > 30 or >20 plus severe daytime sleepiness. Written and oral english language comprehension.