O008 The effect of flow limited breathing and endotypes on night to night variability of sleep apnoea severity

Abstract Background Obstructive sleep apnoea (OSA) is a condition involving repetitive collapse of the upper airway during sleep. The diagnosis and characterisation OSA based primarily off apnoea-hypopnoea index (AHI) in single-night study. Recent data have demonstrated night to variability (NNV) severity. Knowledge which patients more variable would improve long-term risk stratification management. However, patient polysomnographic characteristics associated with high NNV not been completely explored. This study aims determine whether pattern flow limited breathing (FLB) underlying endotypes are predictive those Methods 71 were identified from placebo arm randomized controlled trials testing novel interventions. Each had undergone two studies. Patient characteristics, medical history both studies accessed. Sleep processed using established algorithms quantify degree FLB as well endotypes. Differences between each analysed for agreement, change severity OSA. Progress date Ethics approval has obtained statistical analysis. Intended outcome impact It expected that will be mild moderate OSA, across multiple nights help predict compared stable disease.