Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Oct 24, 2017; 7(5): 260-268
Published online Oct 24, 2017. doi: 10.5500/wjt.v7.i5.260
Prediction of delayed graft function using different scoring algorithms: A single-center experience
Magda Michalak, Kristien Wouters, Erik Fransen, Rachel Hellemans, Amaryllis H Van Craenenbroeck, Marie M Couttenye, Bart Bracke, Dirk K Ysebaert, Vera Hartman, Kathleen De Greef, Thiery Chapelle, Geert Roeyen, Gerda Van Beeumen, Marie-Paule Emonds, Daniel Abramowicz, Jean-Louis Bosmans
Magda Michalak, Rachel Hellemans, Amaryllis H Van Craenenbroeck, Marie M Couttenye, Gerda Van Beeumen, Daniel Abramowicz, Jean-Louis Bosmans, Department of Nephrology-Hypertension, Antwerp University Hospital, B-2650 Edegem, Belgium
Kristien Wouters, Department of Medical Statistics, Antwerp University Hospital, B-2650 Edegem, Belgium
Erik Fransen, StatUa Center for Statistics, University of Antwerp, B-2610 Wilrijk, Belgium
Bart Bracke, Dirk K Ysebaert, Vera Hartman, Kathleen De Greef, Thiery Chapelle, Geert Roeyen, Department of Hepatobiliary, Endocrine and Transplantation Surgery, Antwerp University Hospital, B-2650 Edegem, Belgium
Marie-Paule Emonds, Histocompatibility and Immunogenetic Laboratory, Belgian Red Cross-Flanders, 2800 Mechelen, Belgium
Author contributions: Michalak M, Abramowicz D and Bosmans JL designed the study; Michalak M collected and analyzed the data and wrote the first draft of the manuscript; Abramowicz D and Bosmans JL contributed to the analysis of the data and the finalization of the manuscript; Wouters K and Fransen E provided the statistical analysis; Van Beeumen G and Emonds MP contributed to the collection of the patient-related data; Hellemans R, Van Craenenbroeck AH, Couttenye MM, Bracke B, Ysebaert DK, Hartman V, De Greef K, Chapelle T and Roeyen G were responsible for the medical and surgical management of the patients.
Institutional review board statement: This study was approved by the Ethic Committee of the Antwerp University Hospital (Ref. 16/34/339).
Informed consent statement: Since this was a retrospective study, a written informed consent could not be obtained from the patients. However, all patients agreed verbally for the data collection.
Conflict-of-interest statement: This project was an investigator driven study without any support from external organizations. The authors have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jean-Louis Bosmans, MD, PhD, Professor of Medicine, Department of Nephrology-Hypertension, Antwerp University Hospital, Wilrijkstraat 10, B-2650 Edegem, Belgium. jeanlouis.bosmans@uantwerpen.be
Telephone: +32-3-8213421 Fax: +32-3-8290100
Received: December 19, 2016
Peer-review started: December 25, 2016
First decision: February 17, 2017
Revised: March 31, 2017
Accepted: May 3, 2017
Article in press: May 5, 2017
Published online: October 24, 2017
Abstract
AIM

To compare the performance of 3 published delayed graft function (DGF) calculators that compute the theoretical risk of DGF for each patient.

METHODS

This single-center, retrospective study included 247 consecutive kidney transplants from a deceased donor. These kidney transplantations were performed at our institution between January 2003 and December 2012. We compared the occurrence of observed DGF in our cohort with the predicted DGF according to three different published calculators. The accuracy of the calculators was evaluated by means of the c-index (receiver operating characteristic curve).

RESULTS

DGF occurred in 15.3% of the transplants under study. The c index of the Irish calculator provided an area under the curve (AUC) of 0.69 indicating an acceptable level of prediction, in contrast to the poor performance of the Jeldres nomogram (AUC = 0.54) and the Chapal nomogram (AUC = 0.51). With the Irish algorithm the predicted DGF risk and the observed DGF probabilities were close. The mean calculated DGF risk was significantly different between DGF-positive and DGF-negative subjects (P < 0.0001). However, at the level of the individual patient the calculated risk of DGF overlapped very widely with ranges from 10% to 51% for recipients with DGF and from 4% to 56% for those without DGF. The sensitivity, specificity and positive predictive value of a calculated DGF risk ≥ 30% with the Irish nomogram were 32%, 91% and 38%.

CONCLUSION

Predictive models for DGF after kidney transplantation are performant in the population in which they were derived, but less so in external validations.

Keywords: Delayed graft function, Kidney transplantation, Nomogram, Receiver operating characteristic curve, Risk calculation

Core tip: In this single centre, retrospective study we compared the incidence of observed delayed graft function (DGF) in 247 consecutive kidney transplant recipients with the predicted risk of DGF according to 3 different nomograms. Although the Irish nomogram provided an acceptable predictive value for the global study population, this calculator did not allow to make an accurate prediction of DGF at the individual level. Our study suggests that currently available predictive models for the risk of DGF after kidney transplantation are predictive in the population in which they were derived, but they lose their predictive value in external validations.