Clinical Utility of Obstructive Sleep Apnoea Physiology in Predicting Response to Treatment

This intervention study will investigate the effect that making additional physiological information available to clinicians and patients at the time of obstructive sleep apnoea diagnosis has on treatment referral patterns and patient outcomes. Over the last 5yrs there has been an accumulating body of evidence that understanding an individual patient's physiology can help predict response to treatment for obstructive sleep apnoea. In particular understanding the contribution of loop gain, arousal threshold, upper airway dilator muscle activity and upper airway anatomy. These experimental parameters are not available for clinical use. Our group has developed tools that allow for this information to be made readily available to clinicians at the time of OSA diagnosis. The aim of this study will be to make measurements of an individual's loop gain, arousal threshold, upper airway dilator muscle activity and upper airway anatomy at the time of obstructive sleep apnoea diagnosis. Our tool allows for these measurements to be made from routinely collected clinical data (sleep study) and thus does not require any additional testing above and beyond standard clinical practice. The tool that we will employ for the purpose of this study is a bespoke Matlab code that models the respiratory system. We have currently employed this methodology in ober a dozen clinical studies in Australia and the USA. The tool is experimental and not commercially available. We take regular clinical physiological data (sleep study) and feed that data into our MATLAB code which analyzes the signals and outputs the variables mentioned above. This is then output in a report that clinicians can read. The MATLAB code and analysis is made on data collected using standard sleep study setup. No additional instrumentation or equipment is required. The additional physiological information will be made available at the time of diagnosis and will be kept with the patient's sleep study results (medical records) so that it can be referred back to at any time. The additional physiological information will be kept with the patient's medical record in accordance with usual practice for keeping and maintaining medical records see https://www2.health.vic.gov.au/about/legislation/health-records-act The first year of the study (observational arm) will be comppared to the second year of the study (interventional arm) to understand how clinicians treatment patterns have changed with the access to additional physiological parameters (treatment modality recommended, number of treatment trials for a given patient, patient ouutcomes including sleepp study results and QOL measures).