Predicting potential survival benefit of renal transplantation in patients with chronic kidney disease

Abstract

Background: To facilitate decision-making about treatment options for patients with end-stage renal disease considering kidney transplantation, we sought to develop an index for clinical prediction of risk for death.

Methods: We derived and validated a multivariable survival model predicting time to death in 169,393 patients with end-stage renal disease who were eligible for transplantation. We modified the model into a simple point-system index.

Results: Deaths occurred in 23.5% of the cohort. Twelve variables independently predicted death: age, race, cause of kidney failure, body mass index, comorbid disease, smoking, employment status, serum albumin level, year of first renal replacement therapy, kidney transplantation, time to transplant wait-listing and time on the wait list. The index separated patients into 26 groups having significantly unique five-year survival, ranging from 97.8% in the lowest-risk group to 24.7% in the highest-risk group. The index score was discriminative, with a concordance probability of 0.746 (95% CI 0.741-0.751). Observed survival in the derivation and validation cohorts was similar for each level of index score in 93.9% of patients.

Interpretation: Our prognostic index uses commonly available information to predict mortality accurately in patients with end-stage renal disease. This index could provide valuable quantitative data on survival for clinicians and patients to use when deciding whether to pursue transplantation or remain on dialysis.

Figure 1

Prognostic variables and scoring system of index for the prediction of risk of death among patients with end-stage renal disease eligible for transplantation. *To calculate the index score of a patient, points for all factors that apply are summed. †Factor for which points are assigned to all patients. ‡Includes pre-emptive transplantation.

Figure 2

Comparison of predicted and actual risk of death at five years, by index score. The predicted (red line) and observed five-year mortality rates (vertical axis) in the derivation cohort (blue line) and validation cohort (green line) for each prognostic index score (horizontal axis) are shown. Vertical bars = 95% confidence intervals for the observed mortality rates.