The clinical epidemiology of young adults starting renal replacement therapy in the UK: presentation, management and survival using 15 years of UK Renal Registry data

Abstract

Background: Clinical epidemiology data for young adults on renal replacement therapy (RRT) are lacking. While mostly transplanted, they have an increased risk of graft loss during young adulthood.

Methods: We combined the UK Renal Registry paediatric and adult databases to describe patient characteristics, transplantation and survival for young adults. We grouped patients 11-30 years of age starting RRT from 1999 to 2008 by age band and examined their course during 5 years of follow-up.

Results: The cohort (n = 3370) was 58% male, 79% white and 29% had glomerulonephritis. Half (52%) started RRT on haemodialysis (HD). Most (78%) were transplanted (18% pre-emptive, 61% as second modality); 11% were not listed for transplant. Transplant timing varied by age group. The deceased:living donor kidney transplant ratio was 2:1 for 11-<16 year olds and 1:1 otherwise. Median deceased donor transplant waiting times ranged from 6 months if <16 years of age to 17 months if ≥21 years. Overall 8% died, with being on dialysis and not transplant listed versus transplanted {hazard ratio [HR] 16.6 [95% confidence interval (CI) 10.8-25.4], P < 0.0001} and diabetes versus glomerulonephritis [HR 4.03 (95% CI 2.71-6.01), P < 0.0001] increasing mortality risk.

Conclusions: This study highlights the frequent use of HD and the importance of transplant listing and diabetes for young adults. More than half the young adults in our cohort started renal replacement therapy on HD. One in 10 young adults were not listed for transplant by 5 years and were ∼20 times more likely to die than those who were transplanted. Diabetes as a primary renal disease was common among young adults and associated with increased mortality. Overall, almost 1 in 10 young adults had died by 5 years from the start of RRT.

Keywords: clinical epidemiology; dialysis; kidney transplantation; registries; survival; young adult.

FIGURE 1

Flowchart showing how the cohort was constructed from the UK RR databases. At RRT start, patients were present in one database. During follow-up, data for paediatric patients moved to the adult database if they transferred to adult services. There were no data queries from the adult database. Further details around missing and discordant data are available in Supplementary Table S1. UKRR, UK Renal Registry; RRT, renal replacement therapy.

FIGURE 2

Patient frequency by age group in incident UK young adult RRT patients between 1999 and 2008. Percentages are shown for each group.

FIGURE 3

Ethnic group by age group in incident UK young adult RRT patients between 1999 and 2008. Percentages are shown for each group. P < 0.05, chi-square test.

FIGURE 4

PRD groups by age group in incident young adult RRT patients between 1999 and 2008. Percentages are shown for each group. P < 0.0001, chi-square test. Percentages are shown for each group. PRD is grouped using the 2012 ERA-EDTA coding [12]; ‘Tubulointerstitial disease’ includes structural renal disorders. Subgroup data are available in Supplementary Table S2.

FIGURE 5

Start modality by age group in incident young adult RRT patients between 1999 and 2008. Percentages are shown for each group. Some paediatric patients were known to have received dialysis at RRT start but the type was unknown.

FIGURE 6

Overall modality proportions in the first 5 years of RRT in surviving UK incident young adults. Percentages are shown for each group. Some paediatric patients were known to have received dialysis at RRT start but the type was unknown.