Platelet-to-lymphocyte ratio as a prognostic predictor of mortality for sepsis: interaction effect with disease severity—a retrospective study

Objective The role of platelet-to-lymphocyte ratio (PLR) as an indicator of inflammation has been the focus of research recently. We aimed to investigate the prognostic value of PLR for sepsis. Design A retrospective cohort study. Setting and participants Data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care III database. Data on 5537 sepsis patients were analysed. Methods Logistic regression was used to explore the association between PLR and hospital mortality. Subgroup analyses were performed based on vasopressor use, acute kidney injury (AKI) and a Sequential Organ Failure Assessment (SOFA) score >10. Results In the logistic model with linear spline function, a PLR >200 was significantly (OR 1.0002; 95% CI 1.0001 to 1.0004) associated with mortality; the association was non-significant for PLRs ≤200 (OR 0.997; 95% CI 1.19 to 1.67). In the logistic model using the PLR as a design variable, only high PLRs were significantly associated with mortality (OR 1.29; 95% CI 1.09 to 1.53); the association with low PLRs was non-significant (OR 1.15; 95% CI 0.96 to 1.38). In the subgroups with vasopressor use, AKI and a SOFA score >10, the association between high PLR and mortality was non-significant ; this remained significant in the subgroups without vasopressor use (OR 1.39; 95% CI 1.08 to 1.77) and AKI (OR 1.54; 95% CI 1.20 to 1.99) and with a SOFA score ≤10 (OR 1.51; 95% CI 1.17 to 1.94). Conclusions High PLRs at admission were associated with an increased risk of mortality. In patients with vasopressor use, AKI or a SOFA score >10, this association was non-significant.