Rapid Assay Diagnostic for Acute Stroke Recognition (RADAR): study protocol for a diagnostic accuracy study.

INTRODUCTION: Large-vessel occlusion (LVO) stroke is effectively treated by time-critical thrombectomy, a highly specialised procedure only available in a limited number of centres. Many patients with suspected stroke are admitted to their nearest hospital and require transfer to access treatment, with resulting delays. This study is evaluating the accuracy of a new rapid portable test for LVO stroke which could be used in the future to select patients for direct admission to a thrombectomy centre. METHODS AND ANALYSIS: Rapid Assay Diagnostic for Acute Stroke Recognition (RADAR) is a prospective observational cohort study taking place in stroke units in England. Participants are adults with a new suspected stroke with at least one face, arm or speech (FAST) symptom(s) and known onset within 6 hours or last known to be well 6-24 hours ago. The index test ('LVOne test' (Upfront Diagnostics)), consists of two portable lateral flow assays which use fingerprick capillary blood to detect d-dimer and glial fibrillary acidic protein concentrations. Reference standards comprise independently adjudicated standard CT/MRI brain±CT/MR angiography with senior clinician opinion to establish: ischaemic stroke±LVO; intracerebral haemorrhage; transient ischaemic attack; stroke mimic. Analyses will report sensitivity, specificity and negative and positive predictive values for identification of LVO stroke. Powered using a primary analysis population (≥2 FAST symptoms and known onset within 6 hours), 276 participants will detect a test specificity of 92%. The broader total study population which allows evaluation of the test for milder symptoms and unknown onset times is estimated to be 552 participants. ETHICS AND DISSEMINATION: Ethical (North East-Newcastle & North Tyneside 2 Research Ethics Committee (reference: 23/NE/0043), Health Research Authority and participating National Health Service Trust approvals are granted. Consent is required for enrolment. Dissemination of results will include presentations at conferences, publication in journals and plain English summaries. TRIAL REGISTRATION NUMBER: ISRCTN12414986.

Exploration of Sleep as a Specific Risk Factor for Poor Metabolic and Mental Health: A UK Biobank Study of 84,404 Participants.

PURPOSE: Short and long sleep durations have adverse effects on physical and mental health. However, most studies are based on self-reported sleep duration and health status. Therefore, this longitudinal study aims to investigate objectively measured sleep duration and subsequent primary health care records in older adults to investigate the impact of sleep duration and fragmentation on physical and mental health. METHODS: Data on objective sleep duration were measured using accelerometry. Primary care health records were then obtained from the UK Biobank (n=84,404). Participants (mean age, 62.4 years) were divided into five groups according to their sleep duration derived from the accelerometry data: <5 hours, 5-6 hours, 6-7 hours, 7-8 hours and >8 hours. ICD-10 codes were used for the analysis of primary care data. Wake after sleep onset, activity level during the least active 5 hours and episodes of movement during sleep were analysed as an indication for sleep fragmentation. Binary regression models were adjusted for age, gender and Townsend deprivation score. RESULTS: A "U-shaped" relationship was found between sleep duration and diseases including diabetes, hypertension and heart disease and depression. Short and long sleep durations and fragmented sleep were associated with increased odds of disease. CONCLUSION: Six to eight hours of sleep, as well as less fragmented sleep, predicted better long-term metabolic and mental health.

Objective sleep assessment in >80,000 UK mid-life adults: Associations with sociodemographic characteristics, physical activity and caffeine.

STUDY OBJECTIVES: Normal timing and duration of sleep is vital for all physical and mental health. However, many sleep-related studies depend on self-reported sleep measurements, which have limitations. This study aims to investigate the association of physical activity and sociodemographic characteristics including age, gender, coffee intake and social status with objective sleep measurements. METHODS: A cross-sectional analysis was carried out on 82995 participants within the UK Biobank cohort. Sociodemographic and lifestyle information were collected through touch-screen questionnaires in 2007-2010. Sleep and physical activity parameters were later measured objectively using wrist-worn accelerometers in 2013-2015 (participants were aged 43-79 years and wore watches for 7 days). Participants were divided into 5 groups based on their objective sleep duration per night (<5 hours, 5-6 hours, 6-7 hours, 7-8 hours and >8 hours). Binary logistic models were adjusted for age, gender and Townsend Deprivation Index. RESULTS: Participants who slept 6-7 hours/night were the most frequent (33.5%). Females had longer objective sleep duration than males. Short objective sleep duration (<6 hours) correlated with older age, social deprivation and high coffee intake. Finally, those who slept 6-7 hours/night were most physically active. CONCLUSIONS: Objectively determined short sleep duration was associated with male gender, older age, low social status and high coffee intake. An inverse 'U-shaped' relationship between sleep duration and physical activity was also established. Optimal sleep duration for health in those over 60 may therefore be shorter than younger groups.