MO030CLINICAL EPIDEMIOLOGY, TREATMENT & SURVIVAL OF YOUNG ADULTS STARTING RENAL REPLACEMENT THERAPY IN THE UK USING 15 YEARS OF UK RENAL REGISTRY DATA

Abstract

Introduction and Aims: Comprehensive UK data on young adults (YAs) on renal replacement therapy (RRT) is lacking. 4/5 YAs on RRT will have a renal transplant and international data show a higher risk of graft loss during young adulthood, a time of increasing independence, experimentation and responsibility. We have combined the independent UK Renal Registry (UKRR) paediatric and adult databases to describe patient characteristics, transplantation practice and survival for YAs starting RRT in the UK. Methods: We created a dataset of incident YAs starting RRT over 10 years (1999 to 2008) using data from the UKRR paediatric and adult databases. We grouped subjects into 4 age bands (11 to <16, 16 to <21, 21 to <26 and 26 to 30 years) as there is no consensus as to which age groups constitute young adulthood, and to enable us to examine for age-related trends. We defined primary renal disease (PRD) group by the 2012 ERA-EDTA coding system. We examined 5 years of longitudinal data per subject, with those starting RRT in 2008 being followed to the latest UKRR return in 2013. Results: Overall the cohort were 60% male, 71% white, with 15% aged 11 to <16, 21% aged 16 to <21, 26% aged 21 to <26 and 38% aged 26 to 30. PRD was glomerulonephritis (GN) in 29%, tubulointerstitial disease in 25%, miscellaneous in 21%, systemic disease in 13%, familial/hereditary in 8% and missing/discordant in 3%. PRD varied significantly with increasing age; tubulointerstitial and inherited disorders were replaced with systemic diseases and miscellaneous conditions. Transplantation was the major treatment although 86% started RRT on dialysis, with a significant difference in start modality proportions by age. By 5 years, 78% received a transplant (of which 18% were pre-emptive, 61% as second modality, with transplant timing varying significantly by age). The deceased to living kidney transplant ratio was 2:1 in the youngest group and 1:1 otherwise. Median transplant waiting times were 10 months for 11 to 16s, 12 months for those aged 16 to <21 and 16 months if aged ≥21 years. Within 5 years of starting RRT 8% of patients died, with most deaths in the oldest ages in the first 2 years from start. With modality (transplant versus dialysis) analysed as time dependent variable in a Cox regression, the hazard ratio (HR) for death was 10.0 (95% confidence interval (CI) 6.6, 15.2) for those on dialysis, unaffected by adjusting for late referral by excluding events before 90 days. Compared to GN, a PRD of diabetes had an HR for death of 5.0 (95% CI 3.4, 7.3). Conclusions: These new UK results give useful information on an under-studied group and show how the clinical epidemiology of YAs on RRT changes with age. We highlight 3 key areas of concern: 1 in 5 YAs are not transplanted by 5 years, with a tenfold increased HR for death for those on dialysis compared to those transplanted. Almost 1 in 10 YAs have died by 5 years from RRT start, a rate similar to malignant melanoma, and the reasons for this need to be understood. A primary renal disease of diabetes confers additional risk with a fivefold higher risk of death compared to GN. We believe services for YAs starting RRT in the UK should consider additional support for those with diabetes and on dialysis to improve their outcomes. Future research would benefit from uniform data collection across renal YA services and a comparison with prevalent YA cases. We also need qualitative and quantitative data on quality of life and psychosocial well-being to enrich understanding of the impact of RRT in young adulthood.