Airview

All patients randomised to arms B or D will be instructed to return used (empty or part full) liraglutide pens at each prescribing visit. These are assessed by pharmacy staff and volumes recorded and compliance can be calculated accordingly as percentage used per protocol and per individual prescription (if maximum dose is not tolerated).
The CPAP device will be interrogated to determine the duration of usage (minutes per night) with the usage recorded on the case report form (CRF). The initial 3 months of CPAP data will be used for study analysis as per remote monitoring with Airview (Resmed) or by downloading the CPAP machine directly. Compliance calculations will be described in greater detail in the statistical analysis plan but patients returning their machine will still remain in their allocated study arm. Patients will also be issued with treatment diaries to facilitate discussion at each study visit and the data will also be recorded. Patients will be routinely counselled on the importance of using their study intervention as prescribed.

Adherence to the assigned treatment will be recorded at 1, 6 and 12 months. Data regarding CPAP use will be downloaded from a cloud-based telemedicine management platform (AirView, ResMed Corp, San Diego, California, USA), and adherence to the use of the MAD will be determined by an embedded compliance micro-recorder chip (DentiTrac, Braebon, Canada). Non-adherence to the assigned treatment would not exclude the participants from the analysis unless they chose to withdraw from the study. Side effects of treatment will be evaluated by self-reporting using Sleep apnoea Quality of Life Index (SAQLI) questionnaire in a clinical setting. Participants will report the treatment-related side effects at 6 and 12 months.

All participants were asked to complete the ESS and VAS questionnaires, at baseline and after 1 month. During this month, patients with OSA were treated with CPAP (ResMed, San Diego, California, US) and their adherence to the treatment was recorded using remote monitoring (Air view, ResMed, San Diego, California, US). Oxygen saturation was recorded overnight for all participants in their own homes at visit 1. Oxygen saturation was also recorded overnight at visit 2 for patients with OSA. ODI was measured through portable pulse oximetry overnight (Konica Minolta Sensing Inc, Tokyo, Japan).

Participants were recruited from 11 sites across the UK Respiratory Sleep Network. Patients who were referred to their local sleep centre with suspicion of OSA were investigated by home polygraphy sleep tests (ApneaLink Air; ResMed, Sydney, Australia). Automated scoring using both the AASM 2007 and 2012 criteria was applied. AASM 2007 scoring was performed using commercially available automated scoring software (AirView; ResMed). AASM 2012 scoring was performed using an automated algorithm which utilises surrogate measures to identify arousals from sleep associated with hypopnoeas [10 (link)]. Adult patients who were found to have mild OSA (defined as AHI 5–15 events·h⁻¹) were eligible. Exclusions included: body mass index (BMI) ≥40 kg·m⁻², unstable cardiac disease, use of supplemental oxygen, secondary sleep pathology (e.g. periodic limb movement syndrome, narcolepsy, circadian disorder and obesity hypoventilation syndrome), previous CPAP usage, Epworth Sleepiness Scale (ESS) score ≥15, concerns over driving while sleepy or an inability to tolerate a 1-h CPAP tolerance test. There were no entry criteria that would have contributed to bias between the sexes.