Systematic review and meta-analysis of intensive care unit outcomes in critically ill nonagenarians versus octogenarians: Impact on mortality, morbidity, and treatment intensity
1
Issued Date
2025-11-01
Resource Type
ISSN
10367314
Scopus ID
2-s2.0-105020479514
Journal Title
Australian Critical Care
Volume
38
Issue
6
Rights Holder(s)
SCOPUS
Bibliographic Citation
Australian Critical Care Vol.38 No.6 (2025)
Suggested Citation
Raykateeraroj N., Weinberg L., Thanakiattiwibun C., Lao-amornphunkul S., Kitisin N. Systematic review and meta-analysis of intensive care unit outcomes in critically ill nonagenarians versus octogenarians: Impact on mortality, morbidity, and treatment intensity. Australian Critical Care Vol.38 No.6 (2025). doi:10.1016/j.aucc.2025.101454 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/112964
Title
Systematic review and meta-analysis of intensive care unit outcomes in critically ill nonagenarians versus octogenarians: Impact on mortality, morbidity, and treatment intensity
Author's Affiliation
Corresponding Author(s)
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Abstract
Introduction: As life expectancy increases, intensive care units (ICUs) are treating more patients aged 90 years and older. Whether outcomes in nonagenarians differ significantly from those of octogenarians (aged 80–89 years) remains uncertain. Objective: The objective of this study was to compare ICU, in-hospital, and longer-term mortality (3 months–1 year) and treatment intensity between critically ill nonagenarians and octogenarians. Methods: We conducted a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Ovid MEDLINE, Embase, and CENTRAL were searched through October 2024. Studies reporting outcomes for both age groups were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effect models. Results: Eleven retrospective studies were included, involving 138,073 ICU patients (13,717 nonagenarians and 124,356 octogenarians). ICU mortality was comparable overall (OR: 1.30, 95% CI: 0.94–1.80), although heterogeneity was high (I<sup>2</sup> = 87%). In-hospital mortality (OR: 1.20, 95% CI: 1.04–1.39, I<sup>2</sup> = 82%) and longer-term mortality (OR: 1.65, 95% CI: 1.58–1.72, I<sup>2</sup> = 0%) were significantly higher among nonagenarians. Use of renal replacement therapy was significantly lower in nonagenarians (OR: 0.35, 95% CI: 0.26–0.48). Sensitivity analysis excluding short-stay ICU admissions revealed increased ICU mortality in nonagenarians (OR: 1.46, 95% CI: 1.06–2.02), suggesting that the initial comparability may underestimate true differences. Conclusion: Observed similarities in ICU mortality may reflect selection bias towards less severely ill nonagenarians. When short-stay admissions were excluded, a consistent pattern of worse outcomes emerged. These findings highlight the need for individualised ICU decision-making in the oldest old and support future research using matched cohorts that account for illness severity, treatment intensity, and frailty to better understand the true impact of advanced age.