Risk calculator helps GPs predict which kidney disease patients need hospital care

A new study has discovered a way to help GPs predict which people with kidney disease are more likely to go on to develop kidney failure and need dialysis or a kidney transplant in the future.

Led by the University of Leicester and funded by the charity Kidney Research UK and the NIHR Applied Research Collaborations (ARC) East Midlands, the study shows that the Kidney Failure Risk Equation (KFRE) calculator could help doctors plan better care for their patients. It can spot which patients need to be referred to hospital because their kidney disease is more serious, and who can be cared for by their GP.

Planning care means patients receive the treatment they need sooner and are more likely to avoid ‘crash landing’ into kidney failure – urgently needing treatment such as dialysis without the time to prepare. They are also more likely to have a better treatment outcome, and the healthcare system becomes more efficient as it avoids unnecessary referrals.

The KFRE uses data that doctors routinely collect for patients with chronic kidney disease (CKD) - a blood test that measures kidney function (eGFR), a urine test measuring the amount of protein, age and gender - to predict the risk of developing kidney failure.

In the study, published online today in the journal PLOS Medicine, Dr Rupert Major from the University of Leicester discovered that after adjusting the KFRE for use in primary care, the calculator is able to predict someone’s risk of needing dialysis or a kidney transplant in the next two or five years.

“This calculator has been tested in groups of patients across the world, but never in people with CKD in the UK, or in a GP setting,” explains Dr Major, who led the research. “Our study suggests that, at the moment, only one person out of eighteen people with CKD eligible for referral ends up needing dialysis or transplant within five years. This may be reduced to one in fifteen by using KFRE whilst also detecting more people who will require dialysis or a transplant. It will also allow GPs to identify patients who will need dialysis or a transplant in the future earlier, so they can receive more personalised care and ongoing information and support about their condition.”

He continues: “We hope using this calculator will lead to earlier and better care for those patients who will develop kidney failure requiring dialysis or a kidney transplant, whilst reducing unnecessary referrals and the associated emotional strain they might cause to patients and their families.”

CKD care is estimated to cost the National Health Service (NHS) in England around £1.3 billion each year, with £780 million relating to dialysis and kidney transplantation.

Dr Major continues: “It is really exciting to discover that the KFRE tool could change the referral criteria for all patients with CKD. Most importantly, it has spotted potentially unwell patients with higher levels of kidney function who might not previously have been referred to hospital. The risk can also be calculated without needing additional tests, meaning the cost of using it in the NHS is minimal.”

And this study is leading to exciting work in the future. “Firstly, we want other researchers to confirm our findings in further groups of people with CKD,” explains Dr Major. “We are also working with the CKD-PC team who developed the KFRE to improve the predictions we can make. We hope to be able to simultaneously predict a patient’s risk of dying within a period of time alongside their risk of needing dialysis or a kidney transplant. We also want to develop a more dynamic tool that can react to the latest blood or urine test results and monitor changes over time. We hope this will make our predictions even more accurate.”

Elaine Davies, Director of Research Operations at Kidney Research UK said: “We were delighted to support Dr Major’s work through a Clinical Research Fellowship over the past three years and see such an interesting study take place during that time. We hope that this tool will, in time, be used by GPs as part of routine patient care and make a real difference for people with kidney disease.”

• Major, RW et al. The Kidney Failure Risk Equation for prediction of end stage renal disease in UK primary care: An external validation and clinical impact projection cohort study doi:10.1371/journal.pmed.1002955