Stroke Investigation Group in North and Central London (SIGNAL): cohort profile of a prospective large-scale comprehensive stroke registry

PURPOSE: Large-scale stroke registries can provide critical insights into disease mechanisms, progression and healthcare needs, informing prevention and care. However, few collect detailed demographic, brain imaging, and comprehensive long-term follow-up data. To address this, we established the prospective Stroke Investigation Group in North And central London (SIGNAL) registry in 2017. PARTICIPANTS: The SIGNAL registry included 3931 adults aged ≥18 years with confirmed acute stroke (cerebral ischaemia or intracerebral haemorrhage (ICH)) admitted to the University College London Hospital hyperacute stroke unit between January 2017 and 2020, drawn from an ethnically diverse North and Central London population (~1.6 million). Baseline data included demographic, clinical, brain imaging and next-of-kin information. Six month follow-up included measures of functional status and non-motor outcomes (anxiety, depression, fatigue, sleep, pain, language, continence, social participation, cognition) via face-to-face, telephone or postal follow-up methods. FINDINGS TO DATE: The mean age of individuals included in the SIGNAL registry was 72.1 years, and 1806 (45.9%) were female. The ethnic distribution comprised 2365 (60%) white, 649 (16.5%) black and 511 (13%) Asian. Stroke diagnoses included 3371 (85.8%) with cerebral ischaemia and 560 (14.2%) with ICH. On admission, 2240 individuals (57.0%) had a National Institutes of Health Stroke Scale score >4, indicating moderate stroke severity. At hospital discharge, the median functional outcome, measured by the modified Rankin Scale, was 3 (IQR 1-4), indicating moderate disability. At 6 months, functional outcomes measured with mRS were available for 3755 individuals (95.6%) with a median score of 1 (IQR=0-3) and non-motor outcomes were available for 3080 individuals (92.3%). The most prevalent adverse non-motor outcomes were fatigue 1756 (57%), reduced social participation 1694 (55%) and sleep disturbance 1663 (54%). FUTURE PLANS: Further analyses of SIGNAL registry data will investigating associations between stroke mechanisms, subtypes and neuroimaging features and 6-month functional status, non-motor outcomes and cognitive impairment. Longer term follow-up of survivors for ~10 years is also planned.