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Five-Decade Prevalence of Delirium in Pneumonia, Risk Factors, and Associated Mortality: A Systematic Review and Meta-Analysis

E. L. Juárez-Martinez, Aida Araia, Dillan Prasad, Shreya Dhar, K. Nandoliya, I. Sherrington, Catherine Zhao, Annie Wescott et al.

European Respiratory Review, 2025

11 participants · 10 citations

Abstract

Background Delirium can occur in patients with pneumonia, but its prevalence is inconsistent across studies. Unreliable estimates and uncertainty regarding the significance of patient-specific versus microbiological risk factors hinder delirium management and prognosis. Here, we provide robust estimates of delirium prevalence in patients with pneumonia, associated risk factors and association with mortality. Methods We searched five databases (Medline, Cochrane Library, Embase, PsycINFO and Scopus), from inception to 6 August 2024. We included studies in adults hospitalised with pneumonia reporting delirium, encephalopathy or altered mental status. Two investigators extracted data and assessed risk of bias. Summary rates were calculated using random-effects models. We performed prespecified analyses for diagnostic methods, microbiologic factors, clinical factors and mortality, with sensitivity analysis among studies at low risk of bias. The review protocol was registered with PROSPERO: CRD42023385571. Results Delirium prevalence across 126 studies was 22% (95% CI 18–26%) and higher in studies at low risk of bias (40%, 95% CI 24%–58%; n=11). Standardised assessments yielded higher rates than symptom- or International Classification of Diseases code-based assessments (p<0.05). Surprisingly, delirium rates did not differ by microbiological aetiology (p=0.63), including COVID-19, nor by pneumonia origin (p=0.14). Predisposing factors included older age and neurologic and…

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Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 11 participants or records.

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