Association between the direct bilirubin to lymphocyte ratio and mortality in patients with necrotizing fasciitis: a retrospective cohort study.

BACKGROUND

Necrotizing fasciitis (NF) is a rapidly advancing and highly lethal infection of the soft tissues. We investigated the link between the direct bilirubin-to-lymphocyte ratio (DBLR) and 28-day mortality in NF cases.

METHODS

This single-center retrospective cohort study enrolled NF patients admitted to Baise People's Hospital between November 2019 and December 2025. To assess the prognostic value of DBLR, we employed restricted cubic spline (RCS) analysis, Kaplan-Meier analysis, multivariable Cox regression, subgroup analysis, and receiver operating characteristic (ROC) analysis.

RESULTS

A total of 184 patients were included. Patients in higher DBLR quartiles showed more severe hepatic, coagulation, and inflammatory abnormalities, together with higher 28-day mortality. After log10 transformation, RCS analysis showed a significant overall association between log10(DBLR) and 28-day mortality, with no evidence of non-linearity (P for overall < 0.001; P for non-linearity = 0.515). In Cox regression analysis, a higher log10(DBLR) was associated with increased 28-day mortality. This association remained significant after adjustment for age, shock, and LRINEC in Model 3 (HR, 2.119; 95% CI, 1.384-3.243; P < 0.001). Similar results were observed in the SOFA-adjusted and APACHE II-adjusted models. DBLR showed modest-to-acceptable discrimination for 28-day mortality, with an AUC of 0.733 (95% CI, 0.644-0.811).

CONCLUSIONS

An enhanced DBLR is linked to an increased risk of mortality within 28 days in NF. It could serve as a simple additional biomarker for early risk evaluation.