Kidney Transplant Provides Greater Benefit Than Long-Term Dialysis for Patients With Kidney Failure

All patients who are eligible for a kidney transplant should be able to participate in a transplant program because receiving a kidney transplant was demonstrated to be associated with increased survival compared to long-term dialysis, according to the authors of a recent study published in JAMA Network Open. The study is considered a pioneer in quantifying survival benefit through the use of restricted mean survival time (RMST).

Of the 81.5% of study participants who received a kidney transplant, 31.3% died. However, the RMST of patients who had the transplant was greater among those who were indefinitely on the waitlist and did not receive a kidney transplant.

“We found a survival benefit for patients who receive a kidney transplant regardless of time spent on the wait list and for all ages of adults who are candidates for kidney transplant,” wrote study authors in the report.

In prior studies, receiving a kidney transplant has been proven to be a cost-effective treatment that increases survival in patients with kidney failure at a rate greater than patients who receive dialysis. However, previous observational studies were not able to demonstrate the associations between survival advantage and kidney transplant.

During the study, researchers used a target trial—which is an idealized (but unfeasible) randomized trial that can decrease bias in causal estimates from observational research—to find the survival benefit between kidney transplant and long-term dialysis based on the age of the candidate. The secondary aim was to study survival benefit of patients who were on dialysis while waiting for a transplant, specifically studying outcomes across patient age groups.

In this Austrian retrospective cohort study, researchers identified 4445 adults, aged 18 years and older, who were on a wait list for their first single-organ deceased donor kidney transplant. Participants were randomized into 2 groups—the treatment group, who received immediate kidney transplant, and the control group, who only received continued dialysis (who never had the transplant).

The researchers compared RMSTs between transplant and dialysis patients using the Cox approach. They also looked at the age of transplant candidates and applied target trial emulation methods, assigning the primary endpoint to be time from getting a transplant to death.

During the first 2 years on the waitlist, the investigators observed that transplant-eligible patients are well enough to survive while receiving dialysis, which resulted in a smaller net benefit from transplant.

Among those on dialysis, researchers found that the estimated RMST was lower among participants aged 20 years than it was among those aged 60 years at the 10-year follow up. The target trial emulation also found that those who underwent transplant had a greater RMST at the 10-year follow up compared to those who stayed on the waitlist. This difference was less significant at the 5-year follow-up.

Study limitations include follow-up in the subgroup of younger transplant candidates, a relatively small sample size, possible bias from confounding factors, the proportional hazards assumption intrinsic in the Cox method, and possible missing data, and a relatively homogenous study population that limits generalization of the findings.

“Our study based on target trial emulation provides evidence for longer life expectancy after kidney transplant compared with long-term dialysis across different transplant candidate ages and irrespective of time on wait list,” study authors wrote in the report.

Reference

Strohmaier, Susanne, Wallisch, Christine, Kammer, Michael, et al. Survival Benefit of First Single-Organ Deceased Donor Kidney Transplantation Compared With Long-term Dialysis Across Ages in Transplant-Eligible Patients With Kidney Failure. October 7, 2022. JAMA Netw Open. 2022;5(10):e2234971. doi:10.1001/jamanetworkopen.2022.34971