Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul-Sep;108(3):368504251359356.
doi: 10.1177/00368504251359356. Epub 2025 Jul 22.

Comorbidity of PaO2/FiO2 and nonthyroidal illness syndrome synergistically predicts 28-day mortality in sepsis: A retrospective cohort study from the MIMIC-IV database

Wei Song  1 , Jian Wan  1 , Song Chen  1 , Cong Hui Fan  1 , Qian Zhang  1 , Fei Zhong  1 , Tao Zhang  1 , Ye Yuan  1 , Xueke Wu  1 , Yijiong Zhang  1 , Zhen Han  1 , Lixue Wu  1 , Qingzhong Zhao  1
Affiliations

Comorbidity of PaO2/FiO2 and nonthyroidal illness syndrome synergistically predicts 28-day mortality in sepsis: A retrospective cohort study from the MIMIC-IV database

Wei Song et al. Sci Prog. 2025 Jul-Sep.

Abstract

ObjectiveThis study explores the prognostic value of combining the PaO2/FiO2 ratio and nonthyroidal illness syndrome (NTIS) for predicting 28-day mortality in patients with sepsis.MethodsA retrospective cohort study was conducted using data from adult sepsis patients admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were divided into four groups based on PaO2/FiO2 ratio levels and the presence of NTIS (Groups 1-4). Kaplan-Meier (K-M) analysis with the log-rank test was used to compare 28-day mortality among groups. Multivariate Cox regression was performed to evaluate the independent association between group classification and mortality. A restricted cubic spline (RCS) was used to explore the relationship between PaO2/FiO2 ratio and 28-day mortality.ResultsA total of 599 sepsis patients were included in the analysis. Among the four P/F-NTIS stratified groups, Group 4 (P/F ≤ 200 mmHg with NTIS) exhibited the highest 28-day mortality rate (37.11%), significantly higher than Groups 1, 2, and 3 (p < .001). K-M analysis revealed a significantly lower survival probability in Group 4 (log-rank test, p < .001). Univariate Cox regression analysis identified P/F-NTIS classification as significant predictors of 28-day mortality. Multivariate Cox regression analysis confirmed that Group 4 was independently associated with increased 28-day mortality (HR = 1.70, 95% CI [1.08-2.69], p = .022). RCS analysis showed a nonlinear but statistically significant association between P/F ratio and 28-day mortality (p for nonlinearity = .242), further supporting the prognostic relevance of oxygenation status.ConclusionThe combined evaluation of the P/F and NTIS provides a more comprehensive risk stratification approach, allowing for improved 28-day mortality prediction in septic patients.

Keywords: MIMIC-IV database; Sepsis; mortality; nonthyroidal illness syndrome; oxygenation index.

PubMed Disclaimer

Conflict of interest statement

Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Figures

Figure 1.
Figure 1.
Flow chart for inclusion of participants.
Figure 2.
Figure 2.
The RCS analysis for the nonlinear association between the P/F and 28-day mortality.
Figure 3.
Figure 3.
Kaplan–Meier survival analysis curves for 28-day mortality.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Wasyluk W, Wasyluk M, Zwolak A. Sepsis as a pan-endocrine illness-endocrine disorders in septic patients. J Clin Med 2021; 10: 2075. - PMC - PubMed
    1. Cajander S, Kox M, Scicluna BP, et al. Profiling the dysregulated immune response in sepsis: overcoming challenges to achieve the goal of precision medicine. Lancet Respir Med 2024; 12: 305–322. - PubMed
    1. Zhang M, Duan M, Zhi D, et al. Risk factors for 28-day mortality in patients with sepsis-related myocardial injury in intensive care units. J Int Med Res 2021; 49: 3000605211004759. - PMC - PubMed
    1. Black RE, Cousens S, Johnson HL, et al. Global, regional, and national causes of child mortality in 2008: a systematic analysis. Lancet (London, England) 2010; 375: 1969–1987. - PubMed
    1. Park JS, Kim SJ, Lee SW, et al. Initial low oxygen extraction ratio is related to severe organ dysfunction and high in-hospital mortality in severe sepsis and septic shock patients. J Emerg Med 2015; 49: 261–267. - PubMed

LinkOut - more resources