LAUSR

Objectives Cognitive impairment poststroke is progressive. We aimed to synthesise the existing evidence evaluating risk factors and the effects of treatments to prevent/improve cognitive function in patients who had a stroke with cognitive impairment. Design Umbrella review. Data source Medline, PsycINFO, EMBASE, Cochrane and PROSPERO were searched from inception until 11 June 2019. Eligibility criteria Published systematic review (SR) that incorporated randomised controlled trials to investigate an intervention to improve poststroke cognitive impairment, or SR of longitudinal observational studies that evaluated the risk factors of this condition. No restrictions were applied. Data extraction and synthesis From each eligible study, details were recorded by one reviewer in a validated form. Grading of Recommendations, Assessment, Development and Evaluations criteria were used to assess our certainty level of each outcome, and A Measurement Tool to Assess Systematic Reviews 2 to assess quality. Results Altogether, 3464 abstracts were retrieved, 135 full texts were evaluated and 22 SRs were included in the final analysis. From four SRs of observational studies, we found 19 significant associations with postulated risk factors, and those which we determined to be confident about were: atrial fibrillation (3 SRs, 25 original studies); relative risk 3.01 (1.96–4.61), ORs 2.4 (1.7–3.5) and 2.0 (1.4–2.8), leukoaraiosis, multiple and recurrent strokes, ORs 2.5 (1.9–3.4), 2.5 (1.9–3.1) and 2.3 (1.5–3.5), respectively. From 18 SRs of interventional trials, we found that interventions including physical activity or cognitive rehabilitation were enhancing cognitive function, while the certainty of the other interventions was rated low, due to limited methodological quality. Conclusions This review represents common risk factors related to poststroke cognitive impairment, in particular atrial fibrillation, and points to different interventions that warrant attention in the development of treatment strategies. Physical activity and cognitive rehabilitation interventions showed evidence of enhancing cognitive function; however, we could not recommend a change in practice yet, due to lack of strong evidence. PROSPERO registration number CRD42018096667.