Objective To investigate the association between logarithmically transformed lactate-to-hemoglobin ratio (LnLHR) and 28-day mortality in sepsis patients, addressing the critical need for reliable prognostic biomarkers in this high-mortality condition. Methods This retrospective cohort study analyzed 20725 adult sepsis patients from the MIMIC-IV database (2008–2019). The primary exposure was LnLHR calculated from measurements within 24 hours of ICU admission, while the primary outcome was 28-day all-cause mortality. Covariates included demographics, physiological parameters, severity scores, and interventions. We employed multivariable logistic regression and restricted cubic splines to identify potential non-linear relationships. Finally, mediation analysis was used to assess the factors affecting sepsis mortality in LnLHR. Results Elevated LnLHR was independently associated with increased 28-day mortality after comprehensive adjustment (OR: 1. 43, 95% CI: 1. 35–1. 52). We identified a significant threshold effect at LnLHR: −0. 625, above which mortality risk increased dramatically (OR: 3. 812, 95% CI: 3. 131–4. 642). Subgroup analyses revealed the predictive efficacy of LnLHR exhibited significant variation across various factors, including age, the utilisation of norepinephrine, and the severity score. Mediation analysis revealed that minimum temperature, as a potential mechanism linking LnLHR to 28-day mortality, accounted for 9. 2% of the total association. Conclusion LnLHR may represent a promising, readily available prognostic biomarker for sepsis mortality risk stratification, with a clinically meaningful threshold effect. This composite marker integrates critical pathophysiological information and may enhance risk assessment and guide clinical decision-making in sepsis management.
Chen et al. (Thu,) studied this question.