Philip M. Bath, Ellen V. Backhouse, Rosalind Brown, Lisa J Woodhouse, Fergus Doubal, Terence J. Quinn, Hugh S. Markus, Richard J. McManus, John T. O’Brien, Thompson Robinson, David J. Werring, Nikola Sprigg, Adrian Parry‐Jones, Rhian M. Touyz, Steven Williams, Yee‐Haur Mah, Hedley Emsley, Joanna M. Wardlaw, the R4VaD Investigators
INTRODUCTION: Stroke is often followed by vascular cognitive impairment and vascular dementia, the most feared complications of stroke. However, understanding of post-stroke cognitive impairment remains limited. METHODS: Rates, Risks and Routes to Reduce Vascular Dementia (R4VaD) is an observational cohort study of post-stroke cognition. Patients with haemorrhagic or ischaemic stroke, or transient ischaemic attack, were recruited within six weeks of stroke from hospitals across the UK. Consent was obtained from patients with capacity or from relatives/friends in those without capacity. The primary outcome is dementia rate and its severity at two years assessed using a 7-level ordinal cognition outcome. Final dementia rate will be compared in those with mild stroke/TIA (worst NIHSS <=7) versus severe stroke (NIHSS >7). Secondary outcomes will include cognitive impairment, function, mood and quality of life, and predictors of cognitive impairment at one and two years. Data are shown as number (%), median [interquartile range, IQR] or mean (standard deviation, SD). RESULTS: We recruited 2441 patients from 50 hospitals. Of these, 2432 (99.6%) had a qualifying event of stroke or TIA. The mean age was 68.2 years (SD 13.5), females 979 (40.3%), ethnic minority 170 (7.0%), NIHSS <=7 1962 (80.7%), onset to recruitment 5 days [IQR 3-13] and diagnosis ICH 192 (7.9%), ischaemic stroke 2097 (86.2%), TIA 143 (5.9%). The distribution of cognition at baseline (within 6 weeks of onset) was: normal 1300 (53.5%), minor neurocognitive disorder-single domain 351 (14.4%), minor neurocognitive disorder-multi domain 263 (10.8%), major neurocognitive disorder-mild 387 (15.9%), major neurocognitive disorder-moderate 108 (4.4%) and major neurocognitive disorder-severe 23 (0.1%). Participants with more severe stroke were recruited later (8 [IQR 3-17] vs 5 [2-11] days, p<0.001), less likely to have capacity (86.3% vs 96.8%, p<0.001) and more likely to have had an intracerebral haemorrhage (12.0% vs 6.8%, p<0.001). CONCLUSION: We provide baseline data with the statistical analysis plan in the appendix. The data highlight the substantial under-appreciated cognitive burden of stroke, even in the first few days and weeks after onset.