Clinical phenotypes and treatment adherence in OSA.

Background: Obstructive sleep apnoea (OSA) is a common sleep disorder that can present with a variety of clinical symptoms. Continuous positive airways pressure (CPAP) therapy is the treatment of choice in moderate to severe OSA, however long-term adherence to treatment can be challenging. Recent studies have attempted to identify clinical phenotypes which may aid in guiding treatment and thus improve clinical outcomes. This study's aim was to determine the symptom profile at presentation of a cohort of patients with suspected sleep apnoea and how they relate to treatment choice and adherence. Method(s): Retrospective review of new referrals for suspected obstructive sleep apnoea between July 2017 and June 2018 for 2 physicians. Referral letters, physician review letters, polysomnography results and practice management software data were reviewed to establish presenting symptoms, OSA severity, treatment recommendations and CPAP adherence. We attempted to group patients into the clusters as defined by Keenan et al (Sleep 2018), however patients were not clearly demarcated into the published groups. Adequate CPAP adherence was defined as an average of >=4 hr per night. Progress to date: Data on N = 119 patients were reviewed. Of 119 patients, 15 (12.6%) had no OSA, 27 (22.7%) had mild, 31 (26%) moderate and 46 (38.7%) severe OSA. Mean (+/-SD) age, BMI, ESS and AHI were: 53.8 (+/-14.8) years, 32.9 (+/-8) kg/m2, 8.3 (+/-5.4) and 29.4 (+/-24.3) events/hr respectively. Patients frequently presented with more than one symptom group, with 48 patients reporting one symptom category, 45 with two, 20 with three and 6 with 4 symptom categories. The most common symptom on presentation was loud snoring (n = 65), followed by excessive daytime sleepiness (n = 46) and witnessed apnoeas/gasping (n = 44). Other presenting symptom categories included disturbed sleep, tiredness/fatigue and co-morbid risk factors. CPAP therapy was recommended for 73 patients (61%). 25% of patients prescr