P052 Evaluating the importance of 7-day Actigraphy and sleep diaries prior to MSLT, on the diagnosis of a central disorder of Hypersomnolence.

Abstract Background The Multiple Sleep Latency Test (MSLT) is the gold standard for diagnosis of central disorders of hypersomnolence, such as narcolepsy and idiopathic hypersomnia. However, its diagnostic reliability can be affected by unrecognised sleep restriction, circadian misalignment, or inconsistent sleep patterns in the days preceding testing. Recent guidelines from the American Academy of Sleep Medicine (2021) and the Australasian Sleep Association (2024) recommend the use of actigraphy and sleep diaries prior to MSLT, though these tools are not yet universally used in clinical practice. Objective This quality improvement project evaluates the impact of 7-day actigraphy and sleep diary utilisation prior to MSLT on diagnostic outcomes within the Flinders Medical Centre (FMC) Sleep Service. The study will assess whether the use of these tools influences enhances diagnostic accuracy. Methods A retrospective audit will review data from 629 adult patients who underwent diagnostic polysomnography (PSG) followed by MSLT at FMC between June 2018 and December 2024. Patients will be allocated into two groups based on whether actigraphy and sleep diaries were completed prior to testing. Key metrics including - MSLT results and final diagnoses - will be compared between groups using appropriate statistical analyses to evaluate differences in diagnostic rates and clinical clarity. Expected Outcomes It is hypothesised that pre-MSLT use of actigraphy and sleep diaries will be associated with improved diagnostic precision and a higher rate of accurate diagnoses of central hypersomnolence. Findings are expected to support the integration of actigraphy into standard pre-MSLT protocols, reinforcing guideline-based, consistent, and evidence-informed clinical practice within Sleep Services.