Aim of the research
To see whether removing and replacing 21 or more litres of fluid from the blood at the time of a standard dialysis treatment reduces death or hospitalisation from cardiac events or infections in people with kidney failure. Effects on quality of life, admission to hospital, symptoms, infection rates and costs will also be examined.
Background to the research
Most people with kidney failure need blood cleaning treatment (haemodialysis) 4 hours 3 times a week up at a hospital/ clinic. This is for the rest of their life unless they are fit to receive a kidney transplant. Survival and quality of life on haemodialysis are poor. The addition of filtration (the removal and replacement of fluid) to regular haemodialysis (which allows toxins to leave the blood with minimal fluid removal/ replacement) is known as haemodiafiltration. This does not noticeably change the dialysis procedure as far as the patient is concerned – it is still 4 hours 3 times a week – it just requires changes in equipment and nurse practice. It does however require a greater volume of high quality water. By removing toxins more effectively, haemodiafiltration may improve survival, especially if high volumes are used (i.e. more than 21L of water removed and replaced per session). On the downside, such volumes of filtration could remove essential proteins or introduce toxins or infections from the water supply. We therefore need to establish if haemodiafiltration results in benefits to patients, is safe and justifies any additional financial and environmental (e.g. water) costs.
Design and methods used
This study will randomly allocate patients already on dialysis in one of 20 centres in the UK to either continue on haemodialysis or switch to haemodiafiltration. A research nurse will collect the initial clinical information. All follow-up will be carried out using data already routinely collected by the UK Renal Registry or by linking with other health care databases. Quality of life information will also be collected by the Registry using paper and electronic forms using methods it has developed for routine collection. Recruiting to this trial may be difficult if clinicians, nurses, and patients have strong preferences. These views may be based on clinical judgement or anecdotal experience. Interviews will be carried out and conversations studied in the preparatory and recruitment stages of the study. Potential or actual barriers to recruitment will be identified and strategies to optimise recruitment developed. This may include pre-emptive design of study materials, training and delivery of feedback while recruitment is underway.
Patient and public involvement
The topic for this registry trial has been discussed and selected by patients on the Registry’s Patient Council and a local kidney patient association. Both groups involve about 15-20 dialysis and former dialysis (transplant) patients. While quality of life is important, the current lack of scientific evidence that quality of life improved with haemodiafiltration was thought to be a risk to the success of the trial. Patients therefore wanted the study to focus on survival and life-threatening hospital admissions, but also look at quality of life, safety and environmental impact.
Dissemination
Findings from the research will be made public through patient newsletters, social media and patient meetings. They will also be written up in research journals and presented at conferences.