Gibb K, Seeley A, Quinn T, et al. - A systematic review and meta-analysis study were conducted to explore whether variations in healthcare complexity were correlated with trends in reported delirium over the last four decades. Researchers applied identical criteria to a previous systematic review, only including studies applying internationally accepted diagnostic criteria for delirium (the Diagnostic and Statistical Manual of Mental Disorders and the International Statistical Classification of Diseases). Applying random effects meta-analysis, estimates were pooled across studies, and meta-regression was applied to calculate temporal changes. They evaluated publication bias with funnel plots. Fifteen additional studies were distinguished to add to 18 studies from the original review. At hospitals, the incidence and prevalence of delirium seems to be stable, though publication bias may have masked true changes. The data considered that delirium remains a challenging and urgent priority for clinical diagnosis and care pathways.