UCL News


Kidney failure patients among worst affected during COVID-19

2 June 2021

The main risk factors associated with the significantly higher numbers of COVID-19 infection in dialysis patients, have been revealed in a study led by UCL researchers.

Around 30,000 people in the UK receive regular dialysis treatment

In the UK, around 30,000 people with kidney failure or disease must visit a medical centre several times a week for dialysis treatment, which helps filter waste products from the blood. Globally the figure is around two million. 

As a result, these patients have been unable to self-isolate during lockdown, leaving them far more exposed to COVID-19 infection.

For the observational study, published in the Clinical Journal of the American Society of Nephrology, researchers examined information on 5,755 patients who received dialysis in 51 clinics in London. Between March 2 and May 31, 2020, 990 (17%) patients tested positive for COVID-19 and 465 (8%) were admitted to hospitals with suspected COVID-19.

Researchers found COVID-19 risks were higher in patients who were older, had diabetes, lived in local communities with higher COVID-19 rates, and received dialysis at clinics that served a larger number of patients.

Risks were lower in patients who received dialysis in clinics with a higher number of available side rooms and also at clinics that were early adopters of mandatory mask wearing for all patients, even before the wearing of masks by everyone in healthcare had become compulsory.

No independent association was seen with sex, ethnicity, or measures of deprivation.

Lead author, Dr Ben Caplin, researcher at UCL Division of Medicine and a renal consultant at the Royal Free Hospital, London, said: “Taken together, the findings confirm the high rates of symptomatic COVID-19 among patients receiving in-centre dialysis and suggest sources of transmission both within dialysis units and patients’ home communities.

“The work also suggests that in addition to isolation of confirmed cases, addressing factors that might reduce transmission from patients without suspected or confirmed disease might provide an additional opportunity to further modify the impact of COVID-19 in this population.”

The study was carried out on behalf of the pan-London COVID-19 renal audit group.

Covid-19 and kidney failure risk

National data confirm patients with kidney failure have been disproportionately impacted by COVID-19. As of July 2020, 822 of the 36,437 COVID-19 associated deaths reported in England occurred in patients with established kidney disease. The majority of these were in patients receiving dialysis treatments and at least 623 (of the 822) occurred in in-centre haemodialysis patients representing 1.7% of all COVID-19 deaths in the United Kingdom, despite them making up less than 0.1% of the population.



Media contact

Henry Killworth

Tel: +44 (0) 7881 833274

E: h.killworth@ucl.ac.uk