- Timothy Ellam, research fellow12,
- Helen Twohig, academic training fellow3,
- Arif Khwaja, consultant nephrologist1
- 1Sheffield Kidney Institute, Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S5 7AU, UK
- 2Department of Cardiovascular Science, University of Sheffield, Sheffield, UK
- 3Academic Unit of Primary Medical Care, Northern General Hospital, Sheffield, UK
- Correspondence to: A Khwaja
- Accepted 19 November 2015
Around half of people aged over 75 meet current diagnostic criteria for chronic kidney disease (CKD). However, labelling them all as diseased is controversial and may cause unnecessary anxiety.1 2 The classification system defining this epidemic of CKD in elderly people is validated primarily as an epidemiological risk stratification tool rather than a clinical aid to patient management. We highlight the need to focus the debate on improving patient centred outcomes rather than just identifying everyone at above average risk.
Controversies in ageing kidneys
Older patients make up a large proportion of those reaching end stage renal disease, with 25% of people starting dialysis in the UK being over 75.3 However, the relative risk of end stage disease is much lower for an elderly patient with CKD than for a younger patient with the same level of kidney function. Thus in a large Scottish CKD cohort followed for more than five years, the individual risk of requiring renal replacement therapy (dialysis or transplant) fell from 14.33 per 100 patient years in 15-25 year olds to just 0.65 per 100 patient years in those aged 75-85.4 An estimated 1.8 million people over 75 in the UK have CKD stages 3-5,5 but in 2013 only 1700 patients in that age group started dialysis, fewer than one in 1000.
Clearly most older people currently labelled as having CKD die with abnormal kidney function rather than because of advanced kidney failure.6 One of the reasons for this is the increased risk of cardiovascular disease that accompanies advanced kidney disease. Indeed, managing cardiovascular risk is often cited as an important reason for early identification of CKD. However, as with the risk of starting dialysis, the …