The relationship between hemoglobin, albumin, lymphocyte, and platelet (HALP) score and 28-day mortality in patients with sepsis: a retrospective analysis of the MIMIC-IV database

In recent years, the hemoglobin, albumin, lymphocyte, and platelet (HALP) score has emerged as a potential marker of immunological and nutritional status. This study aimed to evaluate the association between the HALP score and prognosis in patients with sepsis. This retrospective cohort study analyzed sepsis patients using clinical data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were classified into Low-score and High-score groups. Confounding factors were controlled through propensity score matching (PSM) analysis. The primary outcome was 28-day mortality in individuals with sepsis. Survival probabilities between groups were compared using Kaplan-Meier curves. Multivariable Cox regression analysis and a smoothing spline fitting curve were employed to investigate the relationship between the HALP score and 28-day mortality. ROC curve analysis and subgroup analysis were performed to evaluate the predictive ability of the HALP score and its components. A total of 2,968 sepsis patients were included, with 809 (27.26%) deaths within 28 days. After PSM analysis, the High-score group had a 24% lower risk of 28-day mortality compared to the Low-score group (HR, 0.76; 95% CI, 0.64–0.91). In the unmatched cohort, the multivariable Cox regression model also indicated that the High-score group had a lower 28-day mortality risk (HR, 0.78; 95% CI, 0.67–0.91). The smoothing spline fitting curve showed a nonlinear relationship between the HALP score and 28-day mortality, with an inflection point at 24.69. When the HALP score was below 24.69, an increase of one point in the HALP score was associated with a 2% reduction in 28-day mortality (HR, 0.98; 95% CI, 0.97–0.99). The HALP score provided incremental predictive value for 28-day mortality when combined with the SOFA score. Albumin was identified as the most influential component of the HALP score. Among patients with sepsis, the HALP score exhibited a nonlinear relationship with 28-day mortality. An elevated HALP score is associated with reduced 28-day, 90-day, 360-day, and in-hospital mortality among sepsis patients.