Survival of patients with kidney failure awaiting transplantation stratified by age and ethnicity: population-based cohort analysis

Abstract

Abstract Background Kidney transplantation is the treatment of choice for people living with kidney failure who are suitable for surgery, but survival benefits for older and/or ethnic minority candidates are unclear. To inform decision-making, the survival of patients on a waiting list for kidney transplantation was assessed. Methods A retrospective study was undertaken of registry data for patients with kidney failure listed for transplantation in the UK. From 1 January 2000 until 30 September 2019, all patients listed for a first kidney-alone transplant were included. The primary outcome was all-cause mortality. After testing for violations of the proportional hazards assumption, an extended Cox regression model factoring in transplantation as a time-dependent variable according to the intention-to-treat principle was developed. Results The study cohort included 47 917 patients on a waiting list for kidney transplantation, of whom 34 558 (72.1%) subsequently received a transplant. Transplantation compared with remaining on dialysis was associated with an overall survival benefit (HR 0.17, 95% c.i. 0.16 to 0.18; P < 0.001), occurring immediately within 30 days, and observed regardless of ethnicity. For White kidney transplant candidates aged at least 65 or at least 70 years, a significant survival benefit was observed within 6 months (HR 0.49, 0.29 to 0.82) and 1 year (HR 0.45, 0.25 to 0.79) after transplantation respectively, which contrasted with 3 years after kidney transplantation for candidates from ethnic minorities aged at least 65 years (HR 0.53, 0.36 to 0.78) or at least 70 years (HR 0.53, 0.36 to 0.78). Conclusion Although time-to-survival benefits are stratified by age and ethnicity, all kidney transplant candidates on the waiting list are better off with transplantation compared with remaining on dialysis. The absence of any early postoperative mortality suggests that some high-risk patients with kidney failure may not be receiving transplantation opportunities.