A single-center comparison of 22 competing definitions of delayed graft function after kidney transplantation

Background: This study compared 22 different definitions of delayed graft function (DGF) following kidney transplantation. Materials/Methods: Our study included 497 kidney transplantations from deceased donors at our center between 2005 and 2011. Graft survival analysis including log-rank tests and Cox proportional hazards model was performed. Sensitivity and specificity were calculated in relation to graft failure. Results: Mean follow-up time was 5.1 years. All dialysis-based definitions were associated with graft failure and characterized by high specificity (88–97%), but low sensitivity (25–29%). Hazard ratios ranged from 2.87 to 13.73, with increased risk when dialysis was required earlier and more frequently. The urine output-based definition performed similarly, with an association with graft failure and high specificity (96%), but low sensitivity (21%). Serum creatinine-based definitions were more heterogeneous. Higher sensitivity (4–67%) was found in some of these definitions, but was often associated with lower specificity (47–96%), losing the association with graft failure. Definitions combining different criteria varied in sensitivity (17–62%) and specificity (60–96%). However, some were able to achieve higher sensitivity without compromising too much on specificity, while keeping the association with graft failure. Conclusions: Our results indicate a potential advantage of combined definitions, because they are able to detect a larger group of recipients with increased risk of graft failure.