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RE-BLEED:   A digital platform for identifying bleeding patients – a feasibility study

Why is this study being done?

Bleeding affects up to 40% of all trauma patients, up to 30% of all surgery patients and is one of the commonest causes of death for women giving birth. The presentation and features of bleeding are different between patients – in some cases bleeding is very obvious to recognise, but in other cases bleeding is more “hidden”, for example in the stomach. Bleeding must be stopped promptly to prevent severe illness or death. 

Many studies have shown differences in how patients who bleed are treated. There is also variation in how individual patients respond to the same treatment, with some patients doing better than others. Understanding how variation in practice and patient characteristics affect outcomes will help us design and test improvements in care.

Patients in hospital have regular tests that measure levels of the different types of cells in their blood and its ability to clot. For example, a drop in red blood cells can indicate that patients have suffered bleeding. More advanced blood tests are available that can provide more detailed information on why patients are bleeding and what treatments might be most effective.

What is the purpose of this study?

This study aims to develop a real-time, hospital-wide digital system to identify patients in hospital who have suffered from bleeding and test whether this system could be used in the future to potentially identify patients to recruit into trials of new treatments or blood tests.

Study objectives:

·        Assemble a panel of experts to identify criteria (for example, specific blood test results and drug prescriptions) that could indicate a patient has suffered from bleeding

·        Use historical electronic patient records to test how well these criteria identify patients who have received treatments for bleeding (blood transfusion)

·        Develop and refine a web-based digital system where the most useful criteria can be applied in “real-time” to identify bleeding patients

·        Test how well the digital platform identifies bleeding patients

·       Test whether a significant number of patients identified by the digital platform are willing to allow their routine blood samples tested for blood clotting and endothelial factors.

Who is doing this study?

The study is being conducted by researchers at the University of Oxford, which acts as the sponsor for the research.

Who is included in this study?

All patients admitted to the Oxford University Hospitals NHS Trust will be digitally screened for signs that they have acquired bleeding of any severity.  We will only screen adults (16 years of age or over). We will exclude patients who either:

  1. inform us directly that they do not wish their records used in the study, or
  2. do not consent to having their blood samples being used in the study, or
  3. have completed the NHS-Opt out

How will the study collect and process data?

This study is assessing the feasibility of using a digital system to detect when someone is bleeding during their stay in hospital, using their electronic health care records. The study will collect data in two different stages. Firstly, we will analyse historical data (i.e., from patients previously admitted to hospital) to establish an “algorithm” that can identify patients who are bleeding. Secondly, we will apply this “algorithm” in real-time to screen all patients in the hospital for signs of bleeding.

Stage 1

The Oxford University Hospitals NHS Foundation Trust will extract 10 years of historic patient records including laboratory results, demographics, vital signs, prescriptions and administration of blood products and link them together using name, date of birth, NHS number, postcode and gender.  After they are linked the records will be allocation a unique (pseudonymous) study ID and then all the identifiable data will be removed (known as pseudonymisation).  This occurs before transferring it securely to the study office at the University of Oxford’.  The study office will only hold the pseudonymous study ID.  The pseudo-anonymised record.

Importantly, whilst the information received is specific to each participant, no individual person will be identifiable in any publication arising from this work. Your personal data will not be shared with any 3rd parties and will not be used for any automated decision making or profiling.

Stage 2

Stage 1 will generate a mathematical set of rules (algorithm) that is designed to identify people who are bleeding using real time hospital data.  Stage 2 is designed to test its ability to work in a live hospital environment.  The algorithm will run on the IT systems of the Oxford University Hospitals NHS Foundation Trust.  It will receive data (similar in type to that used in stage 1) in real-time from all patients admitted to the hospital during the study period.  We will store a copy of all this data in identifiable form during each hospital admission.  If the patient shows signs of bleeding we will retain a copy of these records, if they do not we will delete all the data for this admission at the point they leave the hospital.  

A proportion of patients identified as having experiencing bleeding will be approached in person to provide written consent for us to analyse their left over blood samples.  If any patient removes their consent or contacts the study team to ask not to take part, their records will be deleted.  The data of those who consent and those that have bled but not removed their consent, will be pseudo-anonymised in the same manner as used for stage 1 before the records are securely transferred to the University of Oxford.  At the end of the study period the ability to link the identifiable records held in the OUH with the pseudo-anonymous records held by the University of Oxford will also be deleted.

Can I request that my medical records are not used in this study?

Yes. If you decide you do not want your data to be used for this study you can withdraw at any time, without affecting your medical care. There are several ways to do this:

Your personal data is also protected by the General Data Protection Regulation and Data Protection Act 2018. Further details of these protections are given in the study Privacy Notice.


Data protection regulation provides you with control over your personal data and how it is used. When your health care information is being used in research, however, some of those rights may be limited in order for the research to be reliable and accurate. Further information about your rights with respect to your personal data is available at or by contacting the study team using the details below. The University’s data protection officer (DPO) can be reached at .

Further information

If you have further questions or are not happy with the way your data has been handled, please contact the study team using the contact details below.  Alternatively, you can contact the study sponsor on 01865 616480 or  You have the right to lodge a complaint with the Information Commissioner’s Office (0303 123 1113 or

Study team

Professor Peter Watkinson

Kadoorie Centre for Critical Care Research and Education, Level 3, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU

+44 (0)1865 223101