Fluid OverloadTHIRSTNCT05869656
THIRST Alert Trial
A study testing Fluid restriction and Free fluids in people with Fluid Overload and Congestive Heart Failure, run by University College, London at 1 site in United Kingdom.
Trial summary
The aim of this feasibility study is to determine whether an alert embedded within the electronic health record (EHR) causes clinicians to enrol patients into a randomised controlled trial (RCT) comparing oral fluid restriction versus no restriction in patients admitted to hospital with fluid overload. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Fluid Overload, Congestive Heart Failure
- What is being tested?
- Fluid restriction and Free fluids
- Type of treatment
- Pill or oral medicine, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 23 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 3 May 2023to 4 Dec 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Prescribed IV furosemide during the first 48h of their admission as a regular prescription rather than a one-off dose.
- Assessed as being suitable for inclusion in the trial by the responsible clinical team i.e., fluid restriction deemed to be in equipoise.
Who cannot join
- On a surgical, obstetric or critical care ward environment
- Patients who opt out of study
Trial locations and contacts
1 site in 1 country.
About this study
Official title: THIRST Alert Trial - a Randomised Controlled Trial Within the Electronic Health Record of an Interruptive Alert Displaying a Fluid Restriction Suggestion in Patients With the Treatable Trait of Congestion
The aim of this feasibility study is to determine whether an alert embedded within the electronic health record (EHR) causes clinicians to enrol patients into a randomised controlled trial (RCT) comparing oral fluid restriction versus no restriction in patients admitted to hospital with fluid overload.
One of the main causes of fluid overload is heart failure where there is a lack of strong evidence to support the effectiveness of oral fluid restriction in the acute setting. This causes significant variation in clinical practice where decisions on whether or not to impose a restriction in oral fluid intake is based on the preference of the treating clinician rather than robust evidence from research.
Read more
THIRST Alert is a pragmatic randomised controlled trial (RCT), embedded in the EHR, which seeks to determine whether a computerised alert for the clinical team can change clinician behaviour during routine NHS care at University College London Hospitals NHS Foundation Trust (UCLH).
Patients with suspected fluid overload will be identified based on the prescription of intravenous furosemide, a medication used to stimulate diuresis (increased urine output) to remove excess fluid. A repeat prescription of intravenous furosemide within the first 48 hours of an unplanned admission will trigger the alert.
A clinician from the treating team will then be asked to consider enrolling the patient into the RCT if they judge that oral fluid restriction might be beneficial but they have uncertainty about this (clinical equipoise). Enrolled patients will be randomised to either oral fluid restriction of 1 litre per day or no fluid restriction. This will then be actioned through documenting as part of the clinical plan in the patients record and then communicated to the patient and the rest of the clinical team, including nursing staff.
The study will record the number of patients recruited into the trial and the effect of the alert on enrolled patients' subsequent oral fluid intake. There are no additional tests or follow up for patients and the trial finishes on discharge from the study site. All trial outcomes will use data collected from routine care and the study is supported by the UCLH Biomedical Research Centre, funded by NIHR.
Read the detailed description
Trial Design:
A single centre, pragmatic, parallel group randomised controlled trial and feasibility study. The study will be conducted entirely within University College Hospital, at University College London Hospitals NHS Foundation Trust.
Research Hypothesis:
Clinician-facing alerts, delivered through the electronic health records system, provide a feasible method of enrolling patients into pragmatic trials evaluating the effectiveness of routine treatments
Clinical Research question:
In hospitalised patients with fluid overload, does an automated clinician-facing computerised decision support system (CDSS) alert recommendation for either oral fluid restriction (to 1L per day) or no-fluid restriction (continue with free fluids) result in a change in clinical behaviour and change in the oral fluid intake of enrolled patients?
Study participants:
The study population will be patients treated for suspected fluid overload with a regular prescription of intravenous (IV) furosemide within 48 hours of an unplanned hospital admission.
For staff participants, any clinician with prescribing rights for IV furosemide may be exposed to the CDSS alert. For subsequent medical staff, nursing staff and other allied health professionals, patient enrolment into the trial and their treatment allocation status will be communicated through both EHR and clinical processes that are embedded within routine care, including verbal and non-digital patient handover.
Summary of Interventions:
This study will evaluate the effect of a Best practice advisory (BPA) interruptive alert that is embedded within the electronic health record (EHR) used at the study site. The first BPA will ask the treating clinician whether they judge randomisation to either oral fluid restriction or no restriction is appropriate - if yes is selected, randomised allocation to one of two subsequent alerts will occur at the point of care. This intervention will be tested in silico prior to deployment to the live EHR.
Ethics:
This study protocol was approved by the London Riverside Research Ethics Committee (Ref: 22/LO/0889) and sponsored by University College London (Ref: 151938).
- Conditions
- Fluid Overload, Congestive Heart Failure
- Being tested
- Fluid restriction, Free fluids
- Keywords
- Electronic health record, Comparative effectiveness research, Pragmatic trial, Learning health systems, Heart Failure, Treatable trait
- Medical subject headings
- Edema, Heart Failure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fluid restrictionBehavioural
Oral fluid restriction of 1000ml per day
Free fluidsBehavioural
Continue care without any oral fluid restriction
| Study group | Role | What they receive |
|---|---|---|
| Alert recommending oral fluid restriction | Experimental | The alert will suggest to the treating clinician to fluid restrict the patient to 1L of oral fluid per day Receives: Behavioral: Fluid restriction |
| Alert recommending no oral fluid restriction | Active comparator | The alert will suggest to the treating clinician to continue without any oral fluid restriction Receives: Behavioral: Free fluids |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of patients recruited into the trial
The number of patients in which the usual care team thought there was equipoise for oral fluid restriction
Measured: 3 months
Difference in oral fluid intake between intervention and control arms
Difference in documented oral intake (ml)
Measured: 48 hours after randomisation
Secondary outcomes (10)
Adherence to randomised alert recommendation
Proportion of alerts actioned with corresponding clinical documentation
Measured: During trial recruitment window (up to day 2)
Proportion of alerts with clinical orders for nursing staff
Corresponding documentation of nursing receipt of treatment allocation
Measured: During trial recruitment window (up to day 2)
Oral fluid intake
Documented oral fluid intake (ml)
Measured: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Net fluid balance
Documented overall fluid balance (ml)
Measured: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Weight change after randomisation
Weight (kg)
Measured: 48 hours after randomisation
Length of stay
Number of Days
Measured: From day of admission to day of discharge, assessed up to 120 days after trial start date
Frequency of blood test measurements of renal function
Number of times blood tests are measured
Measured: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Prescription of Diuretic medications
Dose and duration of intravenous and oral diuretics
Measured: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Daily change in creatinine
48 hours after randomisation
Measured: From 48 hours after randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Patient reported outcome measure
Visual analog scale (1-10) of wellbeing, thirst perception and breathlessness
Measured: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2023
- Study start3 May 2023
- Primary completion4 Nov 2023
- Study completion4 Dec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Fluid OverloadStudies of the same condition, open and under way.
- More trials run by University College, LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Feasibility RCT with an alert intervention that is clinician facing
- Masking
- None (open label)
- Enrolment
- 23 participants (actual)
Sponsor and investigators
- Lead sponsor
- University College, London
- Sponsor type
- University, hospital or other
- Collaborators
- University College London Hospitals, National Institute for Health Research, United Kingdom
- Responsible party
- Sponsor
- Investigators
- Yang Chen, BMBCh, MSc, Principal investigator, UCLTom Lumbers, MBBChir, PhD, Study chair, UCLAnoop D Shah, MBBS, PhD, Principal investigator, UCL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05869656
- Sponsor's protocol ID
- 151938
- Acronym
- THIRST
- Status last verified
- Feb 2025
- First submitted
- 26 Apr 2023
- Last updated
- 6 Feb 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Chen Y, Higgins D, Jani Y, Saleem N, Chafer K, McFarlane E, Roberts T, Harris S, Williams B, Sydes MR, Asselbergs FW, Shah AD, Lumbers RT. Generating evidence using electronic alerts during routine care: a fully automated randomized controlled trial of oral fluid restriction in acute heart failure (THIRST alert trial). Eur Heart J Digit Health. 2026 Jun 23;7(6):ztag098. doi: 10.1093/ehjdh/ztag098. eCollection 2026 Jul.
PubMed 42441295Chen Y, Shah A, Jani Y, Higgins D, Saleem N, Chafer K, Sydes MR, Asselbergs FW, Lumbers RT. Rationale and design of the THIRST Alert feasibility study: a pragmatic, single-centre, parallel-group randomised controlled trial of an interruptive alert for oral fluid restriction in patients treated with intravenous furosemide. BMJ Open. 2024 Jan 11;14(1):e080410. doi: 10.1136/bmjopen-2023-080410.
PubMed 38216198
Study at a glance
From the registry record, last updated by the sponsor on 6 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- THIRST Alert Trial - a Randomised Controlled Trial Within the Electronic Health Record of an Interruptive Alert Displaying a Fluid Restriction Suggestion in Patients With the Treatable Trait of Congestion
- ClinicalTrials.gov ID
- NCT05869656
- Acronym / sponsor ID
- THIRST / 151938
- Conditions
- Fluid Overload, Congestive Heart Failure
- Keywords
- Electronic health record, Comparative effectiveness research, Pragmatic trial, Learning health systems, Heart Failure, Treatable trait
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 23 participants (actual)
- Lead sponsor
- University College, LondonUniversity, hospital or other
- Collaborators
- University College London Hospitals, National Institute for Health Research, United Kingdom
- Study start
- 3 May 2023 (actual)
- Primary completion
- 4 Nov 2023 (actual)
- Study completion
- 4 Dec 2023 (actual)
- First posted
- 22 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this feasibility study is to determine whether an alert embedded within the electronic health record (EHR) causes clinicians to enrol patients into a randomised controlled trial (RCT) comparing oral fluid restriction versus no restriction in patients admitted to hospital with fluid overload.
One of the main causes of fluid overload is heart failure where there is a lack of strong evidence to support the effectiveness of oral fluid restriction in the acute setting. This causes significant variation in clinical practice where decisions on whether or not to impose a restriction in oral fluid intake is based on the preference of the treating clinician rather than robust evidence from research.
THIRST Alert is a pragmatic randomised controlled trial (RCT), embedded in the EHR, which seeks to determine whether a computerised alert for the clinical team can change clinician behaviour during routine NHS care at University College London Hospitals NHS Foundation Trust (UCLH).
Patients with suspected fluid overload will be identified based on the prescription of intravenous furosemide, a medication used to stimulate diuresis (increased urine output) to remove excess fluid. A repeat prescription of intravenous furosemide within the first 48 hours of an unplanned admission will trigger the alert.
A clinician from the treating team will then be asked to consider enrolling the patient into the RCT if they judge that oral fluid restriction might be beneficial but they have uncertainty about this (clinical equipoise). Enrolled patients will be randomised to either oral fluid restriction of 1 litre per day or no fluid restriction. This will then be actioned through documenting as part of the clinical plan in the patients record and then communicated to the patient and the rest of the clinical team, including nursing staff.
The study will record the number of patients recruited into the trial and the effect of the alert on enrolled patients' subsequent oral fluid intake. There are no additional tests or follow up for patients and the trial finishes on discharge from the study site. All trial outcomes will use data collected from routine care and the study is supported by the UCLH Biomedical Research Centre, funded by NIHR.
Detailed description
Trial Design:
A single centre, pragmatic, parallel group randomised controlled trial and feasibility study. The study will be conducted entirely within University College Hospital, at University College London Hospitals NHS Foundation Trust.
Research Hypothesis:
Clinician-facing alerts, delivered through the electronic health records system, provide a feasible method of enrolling patients into pragmatic trials evaluating the effectiveness of routine treatments
Clinical Research question:
In hospitalised patients with fluid overload, does an automated clinician-facing computerised decision support system (CDSS) alert recommendation for either oral fluid restriction (to 1L per day) or no-fluid restriction (continue with free fluids) result in a change in clinical behaviour and change in the oral fluid intake of enrolled patients?
Study participants:
The study population will be patients treated for suspected fluid overload with a regular prescription of intravenous (IV) furosemide within 48 hours of an unplanned hospital admission.
For staff participants, any clinician with prescribing rights for IV furosemide may be exposed to the CDSS alert. For subsequent medical staff, nursing staff and other allied health professionals, patient enrolment into the trial and their treatment allocation status will be communicated through both EHR and clinical processes that are embedded within routine care, including verbal and non-digital patient handover.
Summary of Interventions:
This study will evaluate the effect of a Best practice advisory (BPA) interruptive alert that is embedded within the electronic health record (EHR) used at the study site. The first BPA will ask the treating clinician whether they judge randomisation to either oral fluid restriction or no restriction is appropriate - if yes is selected, randomised allocation to one of two subsequent alerts will occur at the point of care. This intervention will be tested in silico prior to deployment to the live EHR.
Ethics:
This study protocol was approved by the London Riverside Research Ethics Committee (Ref: 22/LO/0889) and sponsored by University College London (Ref: 151938).
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Feasibility RCT with an alert intervention that is clinician facing
| Arm | Type | Receives |
|---|---|---|
| Alert recommending oral fluid restriction | Experimental | Behavioral: Fluid restrictionThe alert will suggest to the treating clinician to fluid restrict the patient to 1L of oral fluid per day |
| Alert recommending no oral fluid restriction | Active comparator | Behavioral: Free fluidsThe alert will suggest to the treating clinician to continue without any oral fluid restriction |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Prescribed IV furosemide during the first 48h of their admission as a regular prescription rather than a one-off dose.
- Assessed as being suitable for inclusion in the trial by the responsible clinical team i.e., fluid restriction deemed to be in equipoise.
Key exclusion criteria (2 listed)
- On a surgical, obstetric or critical care ward environment
- Patients who opt out of study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fluid restrictionOral fluid restriction of 1000ml per day | Behavioural | Alert recommending oral fluid restriction |
| Free fluidsContinue care without any oral fluid restriction | Behavioural | Alert recommending no oral fluid restriction |
Primary outcome
Number of patients recruited into the trial
Time frame: 3 months
The number of patients in which the usual care team thought there was equipoise for oral fluid restriction
Difference in oral fluid intake between intervention and control arms
Time frame: 48 hours after randomisation
Difference in documented oral intake (ml)
10 secondary outcomes
Adherence to randomised alert recommendation
Time frame: During trial recruitment window (up to day 2)
Proportion of alerts with clinical orders for nursing staff
Time frame: During trial recruitment window (up to day 2)
Oral fluid intake
Time frame: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Net fluid balance
Time frame: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Weight change after randomisation
Time frame: 48 hours after randomisation
Length of stay
Time frame: From day of admission to day of discharge, assessed up to 120 days after trial start date
Frequency of blood test measurements of renal function
Time frame: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Prescription of Diuretic medications
Time frame: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Daily change in creatinine
Time frame: From 48 hours after randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Patient reported outcome measure
Time frame: From date of randomisation until date of hospital discharge, assessed up to 120 days after trial start date
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Feb 2025.
- Derived from this study: PubMed 42441295Chen Y, Higgins D, Jani Y, Saleem N, Chafer K, McFarlane E, Roberts T, Harris S, Williams B, Sydes MR, Asselbergs FW, Shah AD, Lumbers RT. Generating evidence using electronic alerts during routine care: a fully automated randomized controlled trial of oral fluid restriction in acute heart failure (THIRST alert trial). Eur Heart J Digit Health. 2026 Jun 23;7(6):ztag098. doi: 10.1093/ehjdh/ztag098. eCollection 2026 Jul.
- Derived from this study: PubMed 38216198Chen Y, Shah A, Jani Y, Higgins D, Saleem N, Chafer K, Sydes MR, Asselbergs FW, Lumbers RT. Rationale and design of the THIRST Alert feasibility study: a pragmatic, single-centre, parallel-group randomised controlled trial of an interruptive alert for oral fluid restriction in patients treated with intravenous furosemide. BMJ Open. 2024 Jan 11;14(1):e080410. doi: 10.1136/bmjopen-2023-080410.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Yang Chen, BMBCh, MSc principal investigator
UCL
Tom Lumbers, MBBChir, PhD study chair
UCL
Anoop D Shah, MBBS, PhD principal investigator
UCL
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fluid restriction and Free fluids in people with Fluid Overload and Congestive Heart Failure, run by University College, London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Feb 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of patients recruited into the trial (time frame: 3 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05869656, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Feb 2025.