A study to compare how well patients do with treatment after undergoing full monitoring in a sleep laboratory versus simplified sleep study recordings to test for possible obstructive sleep apnea

INTERVENTION: Patients will be randomly assigned to management by their sleep physician following disclosure of sleep study information according to one of three levels of testing: Level 1 sleep study: Full polysomnography Level 3 sleep study: Limited sleep study, with airflow, respiratory thoraco‐abdominal movement, ECG and oxygen saturation only Level 4 sleep study: Limited sleep study, with oxygen saturation only Following randomisation, all patients will undergo full polysomnography (PSG) testing over a single night (ie at least 6 hours) in a sleep laboratory. All information will be de‐indentified and transferred to a central sleep laboratory (ie Adelaide Institute for Sleep Health), where studies will be scored using data from channels which correspond to the level of sleep study testing that the patient is randomised to, as well as their full PSG. For patients randomised to the Level 3 or 4 arms, the sleep physician will only be given results for the limited sleep study, with disclosure of the full PSG being withheld until after the 4 month follow‐up period. CONDITION: Obstructive sleep apnea PRIMARY OUTCOME: Functional Outcomes of Sleep Questionnaire (FOSQ) to assess ability to perform activities of daily living in the context of excessive sleepiness SECONDARY OUTCOME: CPAP Adherence (if being prescribed to patient), measured by download of information (ie average hours of use per night) which is stored on CPAP devices Epworth Sleepiness Scale (ESS) to assess daytime sleepiness Health care utilisation and costs, with MBS and PBS data to be obtained from Medicare Australia, monitoring of sleep techinician time to prepare and report sleep studies, CPAP nurse appointments, approximation of CPAP equipment costs, and obtaining hospital admission data during the study by patient questionnaire at the end of the follow‐up period. Patient satisfaction survey, using a questionnaire containing 3 questions about satisfaction with the ir management during the study which is scored on a 7 point Likert Scale Short Form‐12 (SF‐12) to assess quality of life Sleep Apnea Symptoms Questionnaire (SASQ) to assess severity of symptoms of OSA Sleep Physician confidence and treatment decisions, using a questionnaire which rates physicians' confidence in their diagnosis and treatment decisions INCLUSION CRITERIA: 1) Patients must be aged between 25‐80 years. 2) Are referred to a sleep disorders centre for investigation of suspected OSA. 3) Report at least 2 of the following symptoms: snoring, witnessed apneas and/or excessive daytime sleepiness.