Utility of a mathematical nomogram to predict delayed graft function: A single-center experience

Background. In 2003, Irish and colleagues published a weighted nomogram designed to predict the risk of delayed graft function (DGF) in a given transplant. It was anticipated that the predictive nomogram would permit preemptive therapies or allocation decisions based on the risk of DGF. The potential for reducing unfavorable outcomes and expenses appeared significant. This nomogram, however, was developed using population data found in the United States Renal Data System and has not been prospectively validated. Methods. We evaluated the accuracy and utility of this nomogram in all cadaver renal transplants performed at a single transplant center. In addition, we correlated DGF with a variety of independent donor and recipient variables outside the established nomogram. Results. The average nomogram DGF risk was 0.41 (a 41% chance of DGF) among the 169 cases in our population. The mean was 0.45 +/- 0.14 (confidence interval: 0.40-0.49) for the 42 DGF-positive subjects, and 0.40 +/- 0.14 (confidence interval: 0.38-0.43) for the 127 DGF-negatives (t=1.80; P=0.07). Conclusions. Although there was a trend showing the predictive value of the nomogram the overlap was tremendous, limiting the accuracy of the calculation for any single recipient. Prospective application of a nomogram on a case-by-case basis did not contribute meaningful information that could guide clinical decision-making regarding use, allocation or immunosuppressive regimen aimed at minimizing DGF.