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New Onset Kidney Impairment Study (NewKI), follow-on study to the Oxford Renal Study (OxRen)

 Status: Follow Up
0808 2524539 (free phone)


What is Chronic Kidney Disease?

Chronic Kidney Disease (CKD) is a worldwide health problem associated with high morbidity and mortality and its prevalence is increasing. Decreased renal function is a well known predictor of hospitalisation, cognitive dysfunction and reduced quality of life. Cardiovascular disease (CVD) is the primary cause of morbidity and mortality in this population where CKD is regarded as both an accelerator of CVD risk and an independent risk factor for CVD events. Even the earliest stages of CKD are known to be associated with significantly increased risks of cardiovascular morbidity, premature mortality, and decreased quality of life. While the CVD risk in end stage renal failure is high, the healthcare burden resides in early stages of disease as it is more prevalent, affecting around 35% of those over 70 years.

Early stages of CKD are defined on the combination of kidney damage (quantified with evidence of renal damage - imaging or proteinuria) and decreased kidney function (defined as glomerular filtration rate [GFR] estimated from serum creatinine concentration). The National Institute for Clinical Excellence (NICE) recommends using urine creatinine concentration for estimation of GFR using the Modification of Diet in Renal Disease study (MDRD) four variable equation. Since CKD is usually asymptomatic until later stages of the disease (Stage 4+), it may be beneficial to establish efficient detection mechanisms for patients with early-stage CKD. Further, NICE highlight the need for strategies aimed at earlier identification and (where possible) prevention of progression to established renal failure.

What is OxRen?

OxRen is a prospective longitudinal cohort study of 3,200 patients aged 60 years and over in primary care within the Thames Valley region. CKD is common and increasing in prevalence. Cardiovascular disease (CVD) is a major cause of morbidity and death in CKD, though of a different phenotype to the general CVD population. However, there have been relatively few studies detailing the prevalence, incidence and progression of CKD in the UK and no studies collecting primary data on the utility of screening for CKD in the general population. Furthermore, alternative renal biomarkers may have greater accuracy for cardiovascular risk stratification but their predictive role as assessed in prospective studies has not been established. The OxRen population is now being followed up for life in the NewKI study to elucidate the progression and prognosis for CKD during the various stages of the disease.

Lay Summary
Kidney function declines slowly with age and reduced kidney function is termed chronic kidney disease. Around 1 in 10 people have mild CKD. Although only a small proportion of this group will progress to severe kidney disease requiring dialysis or transplantation, CKD also puts people at high risk of cardiovascular disease, in particular stroke, heart failure and sudden death. Even people with very mild CKD have premature stiffening and reduced function of their heart and major arteries. Although CKD is recognised as an increasing problem there have been relatively few studies describing the people who have been diagnosed with the disease. In the OxRend and NewKI studies we will see how many new people are diagnosed with CKD and what happens to everyone over a long period of time (10 years) in order to see what treatments improve, or stop the worsening of kidney function and risk of cardiovascular disease.

Ongoing work

  • Identifying predictors of cardiovascular disease and mortality 

  • Establishing the impact of screening for CKD on treatment and health outcomes

  • Quality of life in people with CKD.

  • Incidence of CKD: To be established through linkages with routinely collected health records.

What is the primary aim?

To establish the prevalence, incidence and progression of CKD in a population demographically representative of the UK general population.

Want to know more?

For GPs   For Patients   For Researchers
If you wish your to express an interest for your surgery to be part of OxRen and are based in the Thames Valley region then you may contact your local Primary Care Research Network via their website. Alternatively you can email us on   If you wish to keep up to date with this study then please bookmark this page for the latest news. For patients who wish to be part of the study your GP surgery needs to be part of the OxRen network. You can ask your GP or feel free to email us at   If you wish to keep up to date with the project then please bookmark this page. If you would like to collaborate in this area of research then please email the Renal Programme lead, Jennifer Hirst.                                                                         


  • Identifying predictors of cardiovascular disease and mortality
  • Establishing the impact of screening for CKD on treatment and health outcomes