Admission CRP as an Independent Predictor of Prolonged Length of Stay in Calculous Acute Pyelonephritis: A Comparative Evaluation With the HALP Score

Background:Stone-associated acute pyelonephritis (APN) carries an increased risk of complicated hospitalization, but prognostic markers for prolonged length of stay (LOS) remain limited.We sought independent predictors of prolonged LOS and compared discriminative performances of C-reactive protein (CRP) and the immuno-nutritional HALP [hemoglobin, albumin, lymphocyte, and platelet] score. Material/Methods:This retrospective, single-center study included 120 patients (n = 118 for HALP-based analyses) with stone-associated APN diagnosed based on clinical, laboratory, and computed tomography findings.Firth-penalized multivariable logistic regression was used to identify independent predictors of prolonged hospital stay (> 5 days).The discriminative performances of CRP and the HALP score were assessed using receiver operating characteristic analysis and compared via the DeLong test. Results:Mean LOS was 7.0 ± 4.2 days, and 53.3% of patients had a prolonged stay.CRP was the only independent predictor of prolonged stay in multivariable analysis.CRP showed better discrimination (area under the curve [AUC], 0.815; cutoff,  103.0 mg/L; sensitivity, 68.8%; specificity, 87.5%) compared with the HALP score (AUC, 0.691; cutoff, < 38; sensitivity, 78.1%; specificity, 57.4%); this difference was statistically significant (DeLong P = 0.013).Both markers were moderately correlated with LOS (CRP: r = 0.571; HALP: r = -0.376;P < 0.001 for both). Conclusions:In stone-associated APN, high admission CRP was an independent predictor of prolonged LOS.A low HALP score was associated with prolonged stay in univariate analysis but not in the multivariable model.Admission CRP may help identify patients at risk of prolonged hospitalization; additional prognostic value of the HALP score requires prospective validation.