BioImpedance Spectroscopy To maintain Renal Output: the BISTRO Trial – a clinical trial in which Kidney Patients are more than just trial participants

Project Lead and Organisation

Professor Simon Davies, Keele University

When did project start?

June 2016

Clinical Requirement

Most patients who develop kidney failure choose unit-based haemodialysis treatment. One of the main functions of dialysis is to control the amount of fluid in the body; too much fluid can lead to harm such as  persistently raised blood pressure that damages the heart and increases the risk of stroke, and may cause fluid to collect in the lungs leading to breathing difficulties, which if allowed to get out of control increases the risk of death. Too little fluid, often as a result of trying to avoid these problems, causes dehydration, cramps and low blood pressure on dialysis and more rapid or complete loss of any remaining kidney function along with its associated benefits. Bioimpedance (BI) is a simple, bedside measurement giving information about body composition, in particular how much excess fluid is present. Clinicians can use this to guide how much fluid should be removed by dialysis in conjunction with the normal clinical assessment of the amount of fluid in the body, but it is not known if this results in better decisions and outcomes for patients.

The Solution

Professor Simon Davies is leading a project to test whether taking regular measurements with a bioimpedance device, which gives information about body composition, improves outcomes for people who have recently started haemodialysis treatment for their kidney failure. In particular the team wants to see if this helps maintain their remaining kidney function as this is associated with improved survival, fewer symptoms of kidney failure, fewer side effects of the dialysis treatment and a better quality of life. We also want to see if sharing the bioimpedance information with patients leads to greater involvement and participation in their treatment.

We are inviting people who still have some remaining kidney function and who are beginning haemodialysis treatment as an outpatient to participate in a clinical trial that compares current best practice with the same treatment, but additionally guided by regular bioimpedance measurements. This UK wide clinical trial aims to include 516 patients from about 30 dialysis units. This is a sufficient number for us to determine whether the additional use of bioimpedance reduces the risk of complete loss of kidney function in the first year of treatment from 3 in 10 patients to 2 in 10 patients. We will also compare between treatments how quickly kidney function is declining, symptoms of kidney failure and haemodialysis, patient– reported measures including confidence in managing their health, as well as robust information to enable a cost benefit analysis of the intervention.


Of 54,000 people in the UK treated with kidney replacement therapies (accounting for approximately 2% of the total NHS budget), 24,000 receive centre-based haemodialysis at an annual cost per patient of £24,000 excluding additional costs such as travel, drugs, access procedures and inpatient episodes. In this high-cost setting bioimpedance has the potential to enhance the productivity of haemodialysis care by helping clinicians make appropriate and safe treatment decisions. BI is mentioned in NICE Diagnostic Guidance 29 “(Multiple frequency bioimpedance devices to guide fluid management in people with chronic kidney disease having dialysis”). BI also has potential to address several of the NHS Outcomes Framework domains, including prevention of premature death, improving outcomes by addressing a number of other NICE chronic kidney disease standards such as cardiovascular risk, blood pressure and avoidance of acute illness episodes and enhancing the quality of life for people on dialysis (i.e. a long-term condition), and contributing through improved engagement and activation to a more positive patient experience.

This project is also taking an advanced approach to Public and Patient Involvement (PPI). There is an experienced PPI co-applicant on the grant, leading the establishment and training of a Patient Advisory Group (PAG) for the trial. The PAG’s role includes reaching out to support sites; engagement with the project management team and having an active voice in the trial at key meetings, and producing and advising on patient facing materials and dissemination.


  • Keele Clinical Trials Unit – Keele University
  • University of Birmingham
  • Bangor University
  • Salford University
  • East and North Hertfordshire NHS Trust
  • North Bristol NHS Trust
  • Royal Free Hospital
  • Birmingham Heartlands NHS Trust
  • Sheffield Teaching Hospitals
  • Central Manchester University Hostpial
  • St James University Hospital
  • D4D
  • Kidney Research UK
  • UK Renal Registry


This project is in receipt of £1,288,508 from the NIHR Health Technology Assessment programme.