Quantifying lead time bias when estimating patient survival in preemptive living kidney donor transplantation

Abstract

Preemptive kidney transplantation is the preferred initial renal replacement therapy, by avoiding dialysis and reportedly maximizing patient survival. Lead time bias may account for some or all of the observed survival advantage, but the impact of this has not been quantified. Using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, we included adult recipients of living donor kidney transplants during 1998‐2017. Patients were transplanted preemptively (n = 1435) or after receiving up to 6 months of dialysis (n = 712). We created a matched cohort using propensity scores, and accounted for lead time (dialysis and estimated predialysis) using left‐truncated Cox models with the primary outcome of patient survival. The median eGFR at transplantation was 6.9 mL/min per 1.73 m2 in the non‐pre‐emptive, and 9.6 mL/min per 1.73 m2 in the preemptive group. In the matched cohort (n = 1398), preemptive transplantation was not associated with a survival advantage hazard ratio (HR) for preemptive vs non‐pre‐emptive 1.12 (95% confidence interval [CI] 0.79‐1.61). Accounting for lead time moved the point estimates toward a survival disadvantage for preemptive transplantation (eg, HR assuming 4 mL/min per 1.73 m2/year eGFR decline, 1.21 [0.85, 1.73]), but in all cases the 95% CIs crossed 1. The optimal timing of preemptive living donor kidney transplantation requires further study.

Comparing the Net Benefits of Adult Deceased Donor Kidney Transplantation for a Patient on the Preemptive Waiting List vs a Patient Receiving Dialysis

“…These issues hamper direct comparisons between those transplanted preemptively and those transplanted from the dialysis waiting list. 26,27 Nonetheless, our analysis is consistent with studies that question the benefit and fairness of DD preemptive transplantation.…”

Preemptive Kidney Transplantation Is Associated With Transplantation Outcomes in Children: Results From the French Kidney Replacement Therapy Registry

“…A recent study aimed to quantify this phenomenon and found no suggestion of patient survival advantage for adult patients undergoing preemptive living donor KT compared with those transplanted within 6 mo of commencing dialysis. 34 In our pediatric population, we mostly found a better graft survival but we did not find a better patient survival because of the low number of deaths. This better graft survival may be explained by the “CKD lead time” mentioned by Irish et al 34 However, to estimate this “CKD lead time,” we would need the glomerular filtration rate at start of KRT, which is not available in the REIN registry.…”

Impact of Different Approaches to Kidney Transplant with and without Chronic Hemodialysis on Cardiac Function and Morphology: A Case–Control Study

“…The health risks associated with dialysis are particularly heightened during the first 3 months after the initiation of this treatment. Previous studies showed longer patient and graft survival in preemptive KTx recipients [14][15][16]. The mortality benefit in preemptive KTx is multifactorial, with the absence of catheter-associated infections and vascular-access-associated complications, and the lower incidence of CV events being the major contributors.…”