Association between HALP score and in-hospital mortality in sepsis patients: a multicenter retrospective cohort study with external validation.

BACKGROUND

The HALP (Hemoglobin, Albumin, Lymphocyte, and Platelet) score integrates key parameters reflecting nutritional and immune status. However, its prognostic value for in-hospital mortality in sepsis patients remains underexplored.

OBJECTIVE

To investigate the association between HALP score and in-hospital mortality in sepsis patients using two large critical care databases.

METHODS

We conducted a retrospective cohort study including adult patients with Sepsis-3 from the eICU Collaborative Research Database (derivation cohort, n = 12,899) and the MIMIC-IV database (validation cohort, n = 3,726). HALP was calculated as (hemoglobin × albumin × lymphocyte count)/platelet count, using first available values upon ICU admission. Restricted cubic spline (RCS) models assessed nonlinear relationships between HALP and mortality. Kaplan-Meier survival curves and multivariable Cox regression models, adjusted for demographics, comorbidities, laboratory values, and Acute Physiology Score III, evaluated survival differences between low- and high-HALP groups. Segmented Cox regression examined associations below and above RCS-derived thresholds.

RESULTS

A total of 16,625 patients were analyzed. RCS analysis demonstrated significant nonlinear associations between HALP and in-hospital mortality in both cohorts (overall P < 0.001; nonlinearity P < 0.001 in eICU, P = 0.002 in MIMIC-IV), with an inflection point near 12.45. Below this threshold, each unit increase in HALP was associated with a 3% reduction in mortality risk (eICU: HR 0.97, 95% CI 0.95-0.99, P = 0.002; MIMIC-IV: HR 0.97, 95% CI 0.94-0.99, P = 0.008). Kaplan-Meier analyses showed significantly higher survival in the high HALP group (eICU: log-rank P = 0.005, HR 0.882, 95% CI 0.808-0.962; MIMIC-IV: log-rank P < 0.001, HR 0.723, 95% CI 0.607-0.862). Multivariable Cox regression confirmed that high HALP remained independently protective after full adjustment (eICU: HR 0.90, 95% CI 0.82-0.98, P = 0.017; MIMIC-IV: HR 0.85, 95% CI 0.74-0.98, P = 0.028).

CONCLUSION

The HALP score demonstrates robust prognostic value for predicting in-hospital mortality in sepsis patients, with consistent nonlinear relationships validated across two large databases. Its simplicity and reliance on routine laboratory parameters support potential clinical application in sepsis risk stratification.