UK Renal Registry 15th annual report: Chapter 5 survival and causes of death of UK adult patients on renal replacement therapy in 2011: national and centre-specific analyses.

INTRODUCTION: These analyses examine a) survival from the start of renal replacement therapy (RRT) based on the total incident UK RRT population reported to the UK Renal Registry, b) survival of prevalent patients. Changes in survival between 1997 and 2011 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 2010) was calculated both from the start of RRT and from 90 days after starting RRT, both with and without censoring at transplantation. Prevalent dialysis patients were censored at transplantation; this means that the patient is considered alive up to the point of transplantation, but the patient's status post-transplant is not considered. Both Kaplan-Meier and Cox adjusted models were used to calculate survival. Causes of death were analysed for both groups. The relative risk of death was calculated compared with the general UK population.
RESULTS: The unadjusted 1 year after 90 day survival for patients starting RRT in 2010 was 87.3%, representing an increase from the previous year (86.6%). In incident patients aged 18-64 years, the unadjusted 1 year survival had risen from 86.0% in patients starting RRT in 1997 to 92.6% in patients starting RRT in 2010 and for those aged ≥65 it had increased from 63.9% to 77.0% over the same period. The age-adjusted one year survival (adjusted to age 60) of prevalent dialysis patients increased from 88.1% in the 2001 cohort to 89.8% in the 2010 cohort. Prevalent diabetic patient one year survival rose from 82.1% in the 2002 cohort to 84.7% in the 2010 cohort. The age-standardised mortality ratio for prevalent RRT patients compared with the general population was 18 for age group 30-34 and 2.5 at age 85+ years. In the prevalent RRT dialysis population, cardiovascular disease accounted for 22% of deaths, infection and treatment withdrawal 18% each and 25% were recorded as other causes of death. Treatment withdrawal was a more frequent cause of death in those incident patients aged ≥65 than in younger patients. The median life years remaining for a 25-29 year old on RRT was 18 years and approximately three years for a 75+ year old.
CONCLUSIONS: Survival of patients starting RRT has improved in the 2010 incident cohort. The relative risk of death on RRT compared with the general population has fallen since 2001.