CALLY Index as a Prognostic Marker for 30-Day Mortality in Fournier Gangrene: A Multicenter Retrospective Cohort Study

Background Fournier gangrene (FG) remains a life-threatening necrotizing infection with persistently high mortality despite advances in surgical and supportive care. Reliable early prognostic markers are therefore essential. The C-reactive protein–albumin–lymphocyte (CALLY) index, which integrates inflammatory, nutritional, and immune status, has shown prognostic value in several critical illness settings, but its utility in FG has not been adequately evaluated. Methods This multicenter retrospective cohort study included 136 adults who underwent surgical treatment for FG between 2015 and 2025. Demographic variables, comorbidities, laboratory parameters, qSOFA scores, and 30-day outcomes were analyzed. Results The 30-day mortality rate was 17% (23/136). Non-survivors had significantly lower albumin and lymphocyte levels, higher CRP levels, and markedly reduced CALLY indices compared with survivors (0.005 vs 0.039, P < 0.001). The CALLY index demonstrated strong discriminative performance for 30-day mortality (AUC = 0.886; 95% CI: 0.780-0.991). A cutoff ≤0.012 provided 82.6% sensitivity and 95.6% specificity. In multivariate analysis, CALLY ≤0.012 (OR 42.61; P < 0.001) and qSOFA score 2-3 (OR 12.97; P = 0.019) emerged as strong independent predictors of mortality, whereas age, sex, uncontrolled diabetes, CAD, immunosuppression, and malignancy were not independently associated with death. Discussion The C-reactive protein–albumin–lymphocyte (CALLY) index was independently associated with 30-day mortality in patients with Fournier gangrene and may serve as a simple adjunctive biomarker for early risk stratification when interpreted alongside established clinical scoring systems such as qSOFA. Incorporating the CALLY index into early risk-stratification algorithms may facilitate timely clinical decision-making and more targeted management strategies for high-risk FG patients.