New score for GPs to predict kidney disease risk

29 Jun 2010

A simple new risk assessment score allowing GPs accurately to predict which of their patients are most likely to develop Chronic Kidney Disease over the next five years has been written by experts at The University of Nottingham. It’s the first calculator of its kind.

A research study of the QKidney® risk algorithm, published today in the Biomed Central Family Practice Journal, has shown that this new score is highly accurate at identifying patients most under threat. The QKidney® risk calculator will allow doctors to decide which patients need testing for the disease or could benefit from assessment, closer monitoring or intervention to reduce their risk.

Chronic Kidney Disease (CKD) is a significant cause of disease and mortality. It is associated with increased risk of death from cardiovascular disease as well as from End Stage Kidney Failure, which can need dialysis or transplantation. Interventions, such as blood pressure control, can help prevent or delay progression to End Stage Kidney Failure in high risk patients.

Whilst the prevention of Chronic Kidney Disease is a key component of the Department of Health NHS Health Checks programme, there have been no tools able to identify systematically patients at high risk of moderate or severe Chronic Kidney Disease. They might benefit from more detailed assessment and closer monitoring or interventions to reduce their risk.

Julia Hippisley-Cox, professor of clinical epidemiology, and Carol Coupland, associate professor in medical statistics at The University of Nottingham, in collaboration with ClinRisk Ltd, developed this new software to help predict which patients need more detailed assessment, closer monitoring or interventions. These could support the NHS Health Check programme.

Professor Hippisley-Cox, lead author of the study, said: “These studies help provide evidence and tools to better identify those at risk developing Chronic Kidney Disease in a systematic way, which will not exacerbate health inequalities.

“Not only will this arm doctors with tools to deliver NHS Health Checks more efficiently, it will identify those most likely to gain from interventions whilst reassuring to those at low risk.”

The researchers studied data collected from 364 general practices contributing to the QResearch database on 1.57 million patients aged 35-74 years. They followed these patients over a seven year period, and identified factors which predicted increase risk of chronic kidney disease such as age, ethnicity, deprivation, smoking status, obesity, blood pressure levels,  family history of kidney disease, use of pain killers (NSAIDS) and other medical conditions such as diabetes, rheumatoid arthritis, health failure, heart disease.

They then incorporated these factors into a new algorithm to calculate an individual risk of developing moderate or severe Chronic Kidney Disease over the next five years. As part of the research, they successfully validated the algorithm in two separate groups of patients. 

A web-based calculator that implements the algorithm can be found at www.qkidney.org. Whilst the calculator has been designed primarily for use by clinicians, it can also be used by patients. Software development kits are available so that system suppliers can easily integrate the calculator algorithm into GP, hospital or pharmacy clinical computer systems to alert doctors to patients who might be at risk of developing Chronic Kidney Disease and might need closer monitoring.

QKidney works well alongside its sister scores, QRisk2 and QDScore — these algorithms predict risk of heart disease (qrisk.org) and diabetes (qdscore.org) respectively.

The QKidney risk algorithm has been designed specifically to support Government plans to implement a systematic and integrated programme of vascular risk and management for people aged between 40 and 74.

The NHS Health Checks involves assessing people’s risk of cardiovascular disease, diabetes and Chronic Kidney Disease and offering a tailored package of prevention. Costing around £250 million to implement, it is estimated that each year it could cut heart attacks and strokes by 9,500, prevent 2,000 deaths and reduce the number of people developing diabetes by 4,000. It will also reduce the financial burden placed on the NHS by the current demands for treatment for these diseases.