Discharge C-reactive protein predicts 90-day readmission after pancreatoduodenectomy: a conditional inference tree analysis

Abstract

Background: The aim of this study was to assess the predictive value of discharge C-reactive protein (CRP) and white blood cell (WBC) levels for 90-day readmission after pancreatoduodenectomy (PD).

Methods: A two-centre, retrospective study was performed between 2008 and 2022. Receiver operating characteristic (ROC) curve analysis was used to determine the predictive value of CRP level and WBC count at discharge. A conditional inference tree (CTREE) was constructed to identify combined risks within subgroups using variables associated with readmission.

Results: Of 438 patients, 54 (12%) were readmitted. The median WBC count at discharge was comparable between the readmitted and not readmitted groups (9.1 vs. 8.5 G/l). The CRP levels at discharge were predictive of 90-day readmission, with an area under the ROC curve (AUC) of 0.63 (95% CI: 0.55-0.63). A CRP concentration below 105 mg/l ruled out 90-day readmission, with a negative predictive value (NPV) of 90% (95% CI: 81%-95%). CTREE confirmed the diagnostic value of CRP at discharge (AUC = 0.68, 95% CI 0.60-0.68). CTREE additionally identified previous wound infection as a second risk factor for readmission in patients with CRP levels less than 101 mg/l (P = 0.003).

Conclusion: CRP levels below 105 mg/l at discharge allow for a safe discharge with a low 90-day readmission rate. Wound infection, but not WBC count, was a positive predictor of 90-day readmission with moderate accuracy, suggesting the need for predischarge imaging for undetected complications in this patient cohort.

Trial registration: Our retrospective analysis did not require registration with a publicly accessible registry.