17 Nov 21. Featured Paper

Prevalence of dementia in ischaemic or mixed stroke populations: systematic review & meta-analysis

Link to paper on Journal of Neurology, Neurosurgery & Psychiatry

Authors

Louise Craig, Zhi Liang Hoo, Toh Zeng Yan, Joanna Wardlaw, Terence J Quinn

Abstract

An understanding of the epidemiology of poststroke dementia (PSD) is necessary to inform research, practice & policy.

With increasing primary studies, a contemporary review of PSD could allow for analyses of incidence & prevalence trends.

Databases were searched using a prespecified search strategy.

Eligible studies described an ischaemic or mixed stroke cohort with prospective clinical assessment for dementia.

Pooled prevalence of dementia was calculated using random-effects models at any time after stroke (primary outcome) & at 1 year (range: 6–18 months), stratified for inclusion of prestroke dementia.

Meta-regression explored the effect of year of study.

Sensitivity analyses removed low-quality or outlier studies.

Of 12 505 titles assessed, 44 studies were included in the quantitative analyses.

At any time point after stroke, the prevalence of PSD was 16.5% (95% CI 10.4% to 25.1%) excluding prestroke dementia & 22.3% (95% CI 18.8% to 26.2%) including prestroke dementia.

At 1 year, the prevalence of PSD was 18.4% (95% CI 7.4% to 38.7%) & 20.4% (95% CI 14.2% to 28.2%) with prestroke dementia included. In studies including prestroke dementia there was a negative association between dementia prevalence & year of study (slope coefficient=−0.05 (SD: 0.01), p<0.0001).

Estimates were robust to sensitivity analyses.

Dementia is common following stroke.

At any point following stroke, more than one in five people will have dementia, although a proportion of this dementia predates the stroke.

Declining prevalence of prestroke dementia may explain apparent reduction in PSD over time.

Risk of dementia following stroke remains substantial and front-loaded, with high prevalence at 1 year post event.

Keywords

• Dementia
• Poststroke dementia (PSD)
• Stroke