Association of Neutrophil Percentage-to-Albumin Ratio With Mortality in ICU Patients With Acute Pancreatitis: A...

To investigate whether the neutrophil percentage-to-albumin ratio (NPAR) predicts 28- and 365-day mortality in ICU patients with acute pancreatitis (AP) and improves the performance of existing ICU scoring systems.

We extracted data on 437 ICU AP patients from the MIMIC-IV 3.0 database. Selection bias was assessed by comparing included and excluded patients. The optimal NPAR cutoff was determined by maximally selected rank statistics. Kaplan-Meier and Cox regression assessed the NPAR-mortality association, with 200-iteration bootstrap resampling for internal validation. Time-dependent AUC, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI) evaluated whether adding NPAR to SAPS II, SOFA, and SIRS improved prediction.

The optimal NPAR cutoff was 34.6. Included patients had more severe disease than excluded patients (SOFA 6.75 vs. 5.32; 28-day mortality 17.4% vs. 11.8%). High NPAR (≥ 34.6) was significantly associated with lower survival (log-rank p < 0.001) and independently predicted 28-day mortality (HR = 2.043, 95% CI 1.235-3.380, p = 0.005) and 365-day mortality (HR = 1.749, 95% CI 1.174-2.606, p = 0.006). After bootstrap validation, optimism-corrected HRs were 1.820 and 1.560, with corrected AUCs of 0.765 and 0.695, respectively. Adding NPAR to SIRS significantly improved AUC (28-day: 0.613 vs. 0.529, p = 0.011; 365-day: 0.580 vs. 0.507, p = 0.004), NRI, and IDI (all p < 0.05), whereas adding NPAR to SAPS II or SOFA yielded no significant improvement (all p > 0.05).

NPAR ≥ 34.6 is an independent predictor of 28- and 365-day mortality in ICU AP patients, with robust internal validation. Combining NPAR with SIRS significantly enhances mortality prediction.