Shaw RC, et al. - Using a prespecified search strategy complemented by hand searching, researchers searched multiple cross-disciplinary electronic databases to examine the evidence around occurrence (incidence or prevalence) of delirium in acute stroke. Of 8,822 titles, 32 papers (6,718 candidates) in the quantitative analysis were included. According to this systematic review and meta-analysis, summary estimate for delirium occurrence was 25%. The occurrence rate was 23% limiting to studies at low risk of bias. Findings suggested that delirium is prevalent and affects 1 in 4 patients with acute stroke. Reported delirium rates may depend on the method of evaluation. Delirium occurrence estimates could be used for auditing, planning intervention research, and informing clinical practice.