What is the NightLife Study and why is it important?

Read our study summary below to find out more...

The NightLife study
This study asks the question whether six-months of overnight dialysis, performed three times a week in a hospital or satellite centre, improves the quality of life of individuals with kidney failure, as compared to those who have shorter dialysis sessions during the day.

Why is the NightLife study needed?
Kidney dialysis is a lifesaving treatment for those with kidney failure. Almost 25,000 people receive regular haemodialysis at a hospital or in a satellite clinic in the UK. Despite the benefits of receiving treatment, people with kidney failure who are on dialysis suffer from lots of intrusive symptoms, impacting on the quality of their life. In most cases, the haemodialysis appointment times last for 4 hours, 3 times per week, with additional travel time. This is often more convenient for the hospital but not always for the individual receiving haemodialysis.

In-centre nocturnal haemodialysis offers the opportunity to receive haemodialysis overnight in a hospital or satellite dialysis clinic whilst asleep. Studies suggest that people who have their dialysis overnight may live longer, feel better and may be able to live a life which is closer to normal. Overnight dialysis is a lengthier treatment, typically 6-8 hours, so more waste products and excess water are removed from the blood. As it removes fluid more slowly, it also helps heart function. Importantly, it frees the person up during the day to socialise, work and care for others. What we know about doing dialysis for longer isn’t perfect though. People who choose to do more dialysis may feel better and live longer for other, completely unrelated reasons. The only way to know for sure is to compare longer treatment times overnight with the standard 4-hour daytime treatment in a well-designed clinical study.


Frequently asked questions

The kidneys have a number of important roles to keep us alive and healthy. This includes removing waste products and excess water by making urine. There are lots of different reasons as to why the kidneys may become damaged either suddenly or over time.

If the kidney function is very low or the kidneys have failed, they do not remove the waste products and excess water. This causes individuals to feel very unwell and has a number of life-threatening complications. ‘Dialysis’ replaces the kidney function by removing the waste products and excess water - it can be used long term to manage kidney failure.  

Haemodialysis is a specific type of dialysis. ‘Haemo-‘ refers to blood and so in haemodialysis, blood is carefully removed from the body, flows through an artificial kidney called a ‘dialyser’, and then is returned to the body. The artificial kidney removes the waste products and excess water. The removal of blood from the body and return after it has been ‘cleaned’ is a controlled and safe process, and uses either a designated blood vessel (fistula) or a dialysis line. The dialysis machine has a special ‘pump’ to ensure the blood flows at the right speed throughout the process.

There are different aspects of dialysis treatment that impact how clean the blood is after treatment. These factors include, but are not limited to, the length of a dialysis session and the speed of the pump. For example, increasing the blood flow will increase the amount of blood cleaned in the same period of time, and increasing the length of dialysis will increase the amount of blood cleaned at the same pump speed.

Individuals receiving haemodialysis are awake for their treatment, and it can either be completed at home (by the individual or with the help of a family member or friend) or, more commonly, at a dialysis unit

Over a third of adults in the UK with kidney failure receive haemodialysis ‘in-centre’. This means they attend a dialysis unit, which may or may not be attached to a local hospital, for haemodialysis.

Although all dialysis treatments are altered for the individual, the standard dialysis routine will involve going to the dialysis three times a week (either a Monday, Wednesday, Friday, or Tuesday, Thursday, Saturday), with each dialysis session lasting around 3.5 to 5 hours (typically 4 hours for most adults in the UK). As this is the most common way to receive haemodialysis, we describe this as ‘conventional haemodialysis’.

Nocturnal haemodialysis is a new type of haemodialysis that is available at a small number of dialysis units across the UK. ‘Nocturnal’ means the haemodialysis takes place overnight, instead of during the day.

There are two key differences between nocturnal haemodialysis and conventional haemodialysis:

  1. The treatment is delivered overnight at the dialysis unit
  2. Each session of haemodialysis is longer, typically 6 to 8 hours, starting around 10-11pm in the evening, and finishing by 6am

Otherwise, the general principles of nocturnal haemodialysis are similar to conventional haemodialysis and individuals attend their haemodialysis on three nights of the week.

Early research suggests there are a number of benefits from nocturnal haemodialysis, when compared to conventional haemodialysis. Importantly, lots of individuals who try nocturnal haemodialysis state they feel better during and immediately after their treatment compared to conventional haemodialysis.

This may be due to nocturnal haemodialysis being a ‘gentler’ treatment compared to conventional haemodialysis. This is because the dialysis session is longer, so the dialysis pump speed can be reduced, and the same amount (and potentially more) waste products and excess water can be removed at a slower pace.

Further to this, individuals have reported feeling generally better in their day-to-day life, with more time available during the day and enhanced quality of life. Clinical monitoring suggests nocturnal haemodialysis leads to better blood test results and blood pressure control, improved heart health and reduced medications, alongside other potential benefits.

Although these findings are promising, especially the impact on the quality of life, the benefits of nocturnal haemodialysis need to be confirmed through robust research on a larger scale.

The short answer is yes, as all medical treatments and interventions have risks. The majority of these risks are the same as for conventional haemodialysis, for example, infection is one of the more frequent complications due to the regular need to access the blood stream through a designated blood vessel (fistula) or dialysis line. A potential risk unique to nocturnal haemodialysis includes more frequent damage to the dialysis access sites (the fistula or dialysis line) because they are being used for a longer period of time for each treatment.

Another potential risk is that any remaining kidney function declines faster compared to conventional haemodialysis. So, what does this actually mean? Essentially, in some individuals requiring dialysis, there is still a very small amount of their own kidneys functioning, and these individuals still pass urine. We know that keeping as much of the real kidney function for as long as possible in individuals on haemodialysis improves their health and increases length of life.

Haemodialysis may speed-up the loss of this remaining kidney function due to prolonged periods of blood being directed away from the body and to the dialysis machine, reducing the blood flow through the kidneys. As a result, in theory, longer dialysis sessions mean blood is diverted away from the body for a longer period of time, and there is more time with reduced blood flow through the kidney.

The specific risks of nocturnal haemodialysis have not yet been fully established and the current evidence suggests it is a safe treatment option for kidney failure. Robust research on a larger scale is required to determine and confirm any possible risks. Also, it is not known whether the overall benefits of nocturnal haemodialysis outweigh the risks of the treatment. We would recommend that for the time being, nocturnal haemodialysis is only commenced when an individual has required haemodialysis for at least 3-months.

Preparation for nocturnal haemodialysis is focussed on ways to feel relaxed and comfortable at the dialysis unit so you can rest and sleep whilst receiving the treatment overnight. Unfortunately, most dialysis units cannot offer single sex bays, however, individuals will be appropriately distanced with curtains drawn round the bed space to ensure privacy.

Also, due to the dialysis units being unable to offer single sex bays, traditional night clothes, like pyjamas and night dresses, cannot be worn. Instead, we would recommend wearing layers of light weight comfy clothing that can be adjusted to suit the temperature of the dialysis unit.

Some people also bring their preferred blankets and bedding for comfort, items to help them relax prior to sleeping, for example reading material or music with headphones, and snacks in case they are hungry at the end of their dialysis session. Most dialysis units will also provide nocturnal haemodialysis ‘starter packs’ which contain eye masks and ear plugs to aid with resting and sleep.

The NightLife study is large research trial that is taking place in a number of dialysis units across the UK. The purpose of this study is to compare the effects of 6-months of nocturnal haemodialysis to conventional haemodialysis. This will help us determine the specific benefits of nocturnal haemodialysis and to check for any potential risks.

The key focus of the NightLife study is whether nocturnal haemodialysis can improve the quality of life for individuals on long-term haemodialysis. Other areas being explored include the impact on blood results, blood pressure, hospital admissions, and medication requirements. There will also be optional extras within the study, such as:

  • interviews or sharing photos about your real life dialysis experience;
  • interviews about how doctors and nurses explain research studies to patients;
  • scans to assess the impact on heart health.

The potential risks will be investigated by monitoring for any complications and collecting samples to determine the impact on remaining kidney function.

There are lots of different ways to contribute to the NightLife study, with the key options involving participating in the study, and providing your advice and feedback in our Patient Participant Involvement and Experience events. 

  1. Study participation

We are aiming to recruit 350 adults requiring long-term haemodialysis across the UK to the NightLife study and recruitment will commence in October 2021. Individuals recruited to the study will be randomly allocated to either conventional haemodialysis or nocturnal haemodialysis. Random allocation is being used as it makes the research more reliable, and so we can have greater confidence in the findings.

After allocation, questionnaires specifically assessing quality of life in adults with kidney disease will be completed, along with blood samples and urine collection (if individuals still produce urine). The individual then starts their allocated treatment, either continuing with conventional haemodialysis or starting nocturnal haemodialysis.

These investigations will be repeated around every month, with some variance depending on the specific investigation. To avoid an unnecessary or extra visits to the hospital, all investigations will be completed during dialysis, for example, blood tests will be taken through the fistula or dialysis line, questionnaires completed during the dialysis session, and containers for urine will be handed to the individual, ready for collection on the next dialysis session. The length of active participation is 6-months.

  1. Patient participation, involvement and experience events

The most valuable people to contribute to research are the individuals, family, friends and carers of those with the underlying condition. This is because to truly understand whether a treatment is of benefit, the input of those affected by the condition is essential. Therefore, we are keen to have individuals requiring haemodialysis and their family, friends or carers participate in our Patient Participation, Involvement and Experience (PPIE) events.

The purpose of these events are to get advice and feedback about the NightLife study at various different stages, such as setting up the study, recruitment of participants, identifying any problems with the study design (e.g. experience of data collection), and communication across the study (with the dialysis units, participants and the researchers).

The events will be flexible and delivered in different ways, to ensure they are inclusive and safe during the COVID-19 pandemic. For instance, the events will include discussions in the following formats: meetings with the research team after a hospital appointment, telephone discussions, letter communications, and virtual platforms (e.g. virtual meetings, e-mail, and forums for discussion). Also, we are very open to suggestions for other ways of organising and hosting these events.

The NightLife study is taking place at dialysis units across the UK. Once recruitment starts in October 2021, the participating centres will be confirmed. 

The NightLife study is available for any adult (18 years old or older) requiring long-term haemodialysis (remained on haemodialysis for at least 3-months) who is able to give informed consent.

 The NightLife study is not available for individuals on haemodialysis:

  • with a confirmed plan to have a transplant from a living donor or to change to a different type of dialysis within the next 6-months
  • already receiving nocturnal haemodialysis (or stopped nocturnal haemodialysis within 3-months of study participation)
  • where conventional haemodialysis is not suitable for their individual treatment needs (e.g. during pregnancy, a unique dialysis regimen and specialised monitoring is needed)
  • who have a life expectancy of less than 6-months
  • already participating in another research trial which may influence the results of the NightLife study

For participation in the NightLife study, individuals will be randomly allocated to either conventional haemodialysis or nocturnal haemodialysis. This is because the results will be more reliable, and we will be able to confidently advise on future treatment practices. For instance, if individuals are able to choose which type of haemodialysis they would like to try, this may influence who the researchers approach to take part in the study and individuals may judge the treatment they have chosen more favourably.

As a result, the findings would not be as reliable to advise future individuals on haemodialysis and how the different treatments may affect them. Randomisation will be done on a 1.33:1 ratio, meaning that for every 3 participants randomised to conventional haemodialysis, 4 participants will be randomised to nocturnal haemodialysis.

However, after participation in the NightLife study, dialysis units will enable individuals to either remain on nocturnal haemodialysis or switch to nocturnal haemodialysis if they have been receiving conventional haemodialysis as part of the study.

No, participation in the NightLife study is completely optional and you can change your mind at any point. For instance, if you decline at first, but at a later date would like to take part, you can still take part in the NightLife study. Similarly, if you have started to take part in the NightLife study and would like to stop, irrespective of the reason (which you do not need to disclose), you can withdraw consent.

Yes, all information collected for the NightLife study will remain confidential. The NightLife study is sponsored by the University of Leicester and funded by National Institute for Health Research (NIHR). Leicester Clinical Trials Unit is overseeing the organisation and management of the study. Professor James Burton, Professor of Renal Medicine and Honorary Consultant Nephrologist, is the Chief Investigator.

Read our full Privacy Notice here.

The University of Leicester is the Data Controller for the participant personal information we will process as part of this research study. Further information on the University can be found here:

The Data Protection Officer is Elisabeth Taoudi, Data Protection Officer and in-house Commercial Lawyer, University of Leicester, University Road, Leicester, LE1 7RH. Tel: 0116 229 7640. Email: [email protected]

Unfortunately, due to the COVID-19 pandemic, the start of the NightLife study has been delayed. However, we are now aiming to open recruitment in October 2021. Not all participating dialysis units will start recruitment at the same time, this will be a staged process over the following 2 years. The NightLife study will be completed in 2025.

The results of the NightLife study will be known by the end of the study, and we will aim to circulate the findings by the end of the study and within the following 6-months. There will be regular updates of the study progression through our social media platforms (Twitter and Facebook) and website.

The findings of the NightLife study will be published in a number of professional journals and presented at kidney conferences. We also plan to distribute the results to the dialysis units, study participants and individuals on haemodialysis across the UK.

To achieve this, we will distribute a NightLife study newsletter to summarise the findings and arrange a Patient Participation Involvement and Experience event to both explain the findings and seek advice on how to distribute the findings further.

In participating with the NightLife study, the only change to your kidney care will be receiving nocturnal haemodialysis if you are randomised to this part of the study, and the additional follow-up measures as part of the study. There will be no specific requirements to change other aspects of your kidney care and no change to the status on the organ transplant list.

Yes, if at any point you would prefer to return to conventional haemodialysis, this will be arranged. To ensure you get the most out of your haemodialysis treatment, we would always recommend discussing any concerns or issues you have with your doctor, dialysis nurse and family before making any decisions.