Development and validation of a novel nomogram and risk score for biliary atresia in patients with cholestasis

Background: Timely discriminating biliary atresia (BA) from other causes of cholestasis is important but challenging.Aims: To develop a useful diagnostic nomogram and a simplified scoring system to diagnosing BA.Study design: All medical records of the patients who were consecutively admitted to our institution with cholestasis from March 2016 to December 2020 were retrospectively searched. The patients were allocated to the derivation cohort ( n = 343) and the validation cohort ( n = 246). Multivariable logistic regression models were used to construct the nomogram. The nomogram was validated in both cohorts. The simplified risk score was derived from the nomogram.Results: The nomogram was constructed based on presence of clay stool, gallbladder length, gallblad-der emptying index, shear wave elastography value, and gamma-glutamyl transferase level. This model showed good calibration and discrimination ability, with the C-index of 0.968 (95% CI: 0.951-0.984). The discriminating ability is most prominent in the 61-90 days group, with AUC of 0.982 (95% CI: 0.955- 1.0 0 0). The simplified risk score identified most patients with very high or low risk of BA, and was capa-ble of exempting 64.3% non-BA patients from intraoperative cholangiogram procedure.Conclusions: This novel diagnostic nomogram had good discrimination and calibration abilities. The sim-plified scoring system showed significant clinical utility.(c) 2021 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.