UK Renal Registry 12th Annual Report (December 2009): chapter 7: survival and causes of death of UK adult patients on renal replacement therapy in 2008: national and centre-specific analyses

Introduction: These analyses examine survival from the start of renal replacement therapy (RRT), based on the total incident UK RRT population reported to the UK Renal Registry, including the 19% who started on PD and the 5% who received a pre-emptive transplant. Survival of prevalent patients and changes in survival between 1997 and 2007 are also reported.

Methods: Survival was calculated for both incident and prevalent patients on RRT and compared between the UK countries after adjustment for age. Survival of incident patients (starting RRT during 2007) was calculated both from the start of RRT and amongst the cohort who survived at least 90 days after RRT, and both with and without censoring at transplantation. Both the Kaplan-Meier and Cox adjusted models were used to calculate survival. Causes of death were analysed for both groups. Relative risk of death was calculated compared with the general UK population.

Results: The 2007 unadjusted 1 year after 90 day survival for patients starting RRT was 86.2%. In incident 18-64 year olds the unadjusted 1 year survival had risen from 85.9% in 1997 to 92.4% in 2007 and for those aged >65 it had risen from 63.8% to 74.9%. The age-adjusted survival (adjusted to age 60) of prevalent dialysis patients rose from 85% in 2000 to 89% in 2007. Diabetic prevalent patient survival rose from 76.5% in 2000 to 83.0% in 2007. The age-standardised mortality ratio for prevalent RRT patients compared with the general population was 28.6 at age 30 years (and was lower than in the 1998-2001 cohort in all age groups up to 45-49) and 4.6 at age 80 years. In the prevalent RRT dialysis population, cardiovascular disease accounted for 29% of deaths, infection 17% and treatment withdrawal 14%. Of deaths, 26% were recorded as uncertain. Treatment withdrawal was a more frequent cause of death in patients aged >65 at start than in younger patients. The median life years remaining for a 25-29 year old on RRT was 20 years and 5 years for a 70 year old.

Conclusions: Incident 2007 and prevalent 2008 patient survival on RRT in all the UK countries for all age ranges and also for patients with diabetes continued to improve. The relative risk of death on RRT compared with the general population has fallen since 2001. Death rates on dialysis in the UK remained lower than when compared with a similar aged population on dialysis in the USA.