Long-Term Outcomes in Stroke Patients with Cognitive Impairment: A Population-Based Study

This study assesses five year outcomes of patients with cognitive deficits within the first three months after stroke. Population-based data from the South London Stroke Register between 1995 and 2018 were studied. Cognitive function was assessed using the Abbreviated-Mental-Test or Mini-Mental-State-Examination. Multivariable Poisson regression models with robust standard errors were constructed, to evaluate relative risks (RRs) and associations between post-stroke deterioration in cognitive function during the first three months on dependency, mortality, depression and institutionalisation. A total of 6504 patients with first-ever strokes were registered with a mean age of 73 (SD: 13.2). During the first three months post-stoke, approximately one-third of these stroke survivors either cognitively improved (37%), deteriorated (30%) or remained unchanged (33%). Post-stroke cognitive impairment was associated with increases, in five years, of the risks of mortality, dependency, depression and being institutionalised by RRs 30% (95% confidence interval: 1.1-1.5), 90% (1.3-2.6), 60% (1.1-2.4) and 50% (1.1-2.3), respectively. Deterioration in cognitive function by 10% or more between seven days and three months was associated with an approximate two-fold increased risk in mortality, dependency, and being institutionalised after one year, compared to stable cognitive function; RRs 80% (1.1-3.0), 70% (1.2-2.4) and two-fold (1.3-3.2), respectively. Monitoring further change to maintain cognitive abilities should be a focus to improve outcomes.