Therapy-efficacy of automatic positive airways pressure therapy with A-Flex compared to standard automatic positive airways pressure therapy in obstructive sleep apnoea (OSA) patients

INTERVENTION: A‐Flex: automatic positive airways pressure device featuring pressure relief technology APAP: standard automatic positive airways pressure device The duration of treatment and follow up during the fixed follow‐up period will be three months in both arms. CONDITION: Obstructive sleep apnoea ; Nervous System Diseases ; Sleep disorders PRIMARY OUTCOME: A‐Flex is as effective as APAP in reducing respiratory events and arousals in patients with OSA, measured with the Apnoea‐Hypopnea Index at baseline. SECONDARY OUTCOME: 1. A‐Flex is more comfortable than APAP, measured using the Visual Analogue Scale [VAS] at baseline; 2. Compliance (internal clock within the device) is higher on A‐Flex compared to APAP, measured at one and three months; 3. Subjective daytime sleepiness is improved on A‐Flex compared to APAP, measured using the Epworth Sleepiness Scale at baseline, one and three months; 4. Quality of life is improved on A‐Flex compared to APAP, measured using the Functional Outcomes of Sleep Questionnaire at baseline, one and three months INCLUSION CRITERIA: 1. Apnoea‐Hypopnoea Index (AHI) greater than 15/h confirmed by full polysomnograph (PSG) 2. Aged greater than or equal to 21 to less than or equal to 65 years, either sex 3. Body mass index (BMI) less than 40 kg/m^2 4. Able to follow the study protocol