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Pre-Hospital Emergency Department Data Sharing Project

In 2019 we published the findings of a research project, funded by the Heath Foundation, which aimed to understand how information about patients can be best used by us, acute hospital trusts and commissioners.

For first time in England, all the care in a patient’s journey from their 999 call, to the care they receive from ambulance crews, to the treatment from hospital teams at emergency departments, can be mapped. This is thanks to the findings of the Pre-Hospital Emergency Department Data Linkage Project (PHED Data).

Historically, front line ambulance crews would take a patient to hospital and, often, we would have little to no further information about the patient’s outcome during and/or following their stay in hospital. PHED Data was designed to see if linking our data to hospitals’ and creating a routine link for this information would lead to benefits for the patient, without compromising confidentiality.

Our clinicians care for people in life-changing situations and rarely get to know if their care has had a positive impact. This is not just a matter of clinical training or morale (although these are important), but the benefits of patient outcome data mean that we could have better opportunity to understand the benefits of our care on all patients.

Will Broughton, College of Paramedics, said “Understanding what happens to patients is a key part of clinical training, supports future decision making and can improve morale. We welcome any projects that allow the sharing of this crucial information and encourage professional development for paramedics.”

PHED Data showed that linking data between us and acute hospital trusts will help us all better understand the patient journey from the ambulance to the emergency department and will now be rolled our across all ambulance trusts and emergency departments in England. Read the executive summary here.

On this page you can find everything you need to know about PHED Data; why we did it, how we did it, the results and what happens next.

PHED Data infographic

  • Background - why we did the study

    Excluding small patient groups, such as those having a pre-hospital cardiac arrest, we did not hold information about what happens to patients after they leave our ambulance and would have no further information about the patient’s outcome during and/or following their stay in hospital. We would record the patient’s data, and so would the hospital. Although the physical handover of our patients and the continuity of clinical care from us to hospital is routine, linking up those two sets of data wasn’t. Therefore, data wise, patient journeys were not connected.

    PHED Data was designed to see if linking our data to hospitals’ and creating a routine link for this information would lead to benefits for the patient, without compromising confidentiality. Specifically, we wanted to know the feasibility of, and potential learning from, retrospectively linking hospital’s patient data to our own and whether it could improve our clinical care and patient outcomes as well as create a continuous electronic journey of the patient journey from the ambulance to the hospital.

    To find this out, we ran a two year mixed-methods research project, which was funded by the Health Foundation as part of the Insight 2014 award funding stream. We partnered with Swansea University, the Nuffield Trust, and Kingston University and St. George’s, The University of London.

    PHED Data aimed to answer three questions:

    1. What are the potential opportunities for and challenges to routinely linking data from the ambulance service to emergency departments?
    2. What understanding can be gained from this linked data which could lead to the improvement of healthcare delivery within the ambulance service and across the wider healthcare economy?
    3. What are the challenges to and opportunities for using these data to inform future commissioning of healthcare?
  • The pilot

    We conducted a small feasibility pilot with one acute trust in north west London which, with the necessary agreements and security, demonstrated that non-identifiable information from the acute trust’s emergency department can be linked to our data.

    For the first time in England, all the steps of a patient journey – from the 999 call to the outcome at the emergency department – could be mapped.

    The pilot also showed that linking data was possible and indicated a potential range of benefits to both organisations.

  • The trial

    In 2015 we received research funding from the Health Foundation (LINK: to expand the pilot. The project team included our staff and researchers from Swansea University (LINK:, the Nuffield Trust ( and Kingston University and St. George’s, The University of London (LINK:

    The trial used six acute NHS Trusts across London – which included 12 emergency departments – and ran for two years from May 2015.

    The project team studied non-identifiable data of patients who had been conveyed to an emergency department by us between 1 April 2012 – 30 June 2016.

    In addition, a log was kept of the work involved on our side in making the data linkage happen. Interviews and focus groups were conducted with key stakeholders including pre-hospital clinicians, emergency operations centre staff, general practitioners, emergency department clinical staff, performance managers and commissioners of the ambulance trust. This qualitative work was designed to seek commentary and explanation of the findings from the analysis.

    Following the completion of the trial, we produced findings about how this data can be best used by us, acute trusts and commissioners.

    We analysed the data looking at:

    • Response times
    • How other healthcare professionals use London Ambulance Service
    • Patient groups who are acutely unwell in the ambulance
    • Patient groups who are not acutely unwell in the ambulance

    At the end of data analysis a series of recommendations was produced with the aim to provide benefits to patients, clinicians and service delivery.

  • Information for patients about the trial

    If your data was used as part of the trial, here are some Q&As explaining the use of your information and about the evaluation of the project.

    Did this project change my treatment?
    No. Only data that was collected during routine care was used in the project, there was no change to treatments. The data sharing happened after your care was completed.

    Was personal information shared?
    No. Any personal information collected by us and the emergency department as part of your care was treated in accordance with standard confidential information handling policies. This project did not handle any personally identifiable data and analysed patient trends rather than individual patient journeys. The project shared non-personally identifiable information with other health organisations for the purpose of delivering the project only. This will be in a strictly controlled and secure environment for the purpose of improving patient care.

    Who reviewed this project?
    The project was evaluated by an independent group at the Faculty Research Ethics Committee, Faculty of Health, Social Care and Education at Kingston and St George’s University, University of London to protect your safety, rights, and dignity. This committee gave a favourable opinion.

    The project had governance approval through the Health Research Authority. We also had a patient and public panel which met every six months and ensured the views of the patient and/or public were represented at every stage of project.

    What happens to the results of the evaluation?

    The results of the project are available on this page. You can read the executive summary, take a look at the blog from The Health Foundation or view our infographic.

  • The results

    Read the results:

    PHED Data showed that not only is linking data between us and hospital trusts possible, but that doing so helps to better understand the patient journey from the ambulance to the emergency department. Now, for the first time in England, all the care in a patient’s journey from their 999 call to their outcome in A&E, can be mapped.

    This trial demonstrated that greater information sharing can lead to significant patient benefits without compromising patient confidentiality. It is essential that partnerships between us, other ambulance services and acute trusts continue to strengthen, and data sharing plays a key role in improving that process.



    You can read the recommendations and the findings in full in the executive summary

    From the findings reported

    • Implement a national information sharing agreement to allow ambulance data to be linked to all emergency departments in England.
    • Place more emphasis on identifying high risk and low risk patient groups at telephone triage
    • Evaluate the current procedure for Healthcare Professionals (HCP) referrals, to ensure the registered clinician is making the phone call.
    • Coding at telephone triage and clinician coding sheets, where possible, should be modified to match the coding system being implemented as part of the Emergency Care Data Set.

    Further analysis of the current linked dataset

    • Understand any demographic influences on ambulance/emergency department use, such as age, gender, social deprivation and ethnicity
    • Evaluate prehospital and emergency department care of specific patient groups e.g. stroke, trauma, mental health and older people who fall
    • Work with clinicians to develop valid and reliable grouping of data items that allow for further analysis of the appropriateness of conveyance to the emergency department for those who are not admitted.

    Commissioning / Performance

    • Identify patient groups who may benefit from alternatives to emergency departments such as patients that leave before being seen.
    • Understanding the effects of long ambulance response times, patient flow from ambulance to emergency department, the effects of emergency department closures and collaborative demand modelling.
    • Identifying groups/ clinician training that may enable a prehospital contribution to admission avoidance.
  • What happens next?

    NHS England approved the bid to run this project nationally. The results of the project now form the Ambulance Data Set which will standardise and link data nationally, and will be rolled out across all ambulance services and emergency departments across England by 2022.

    PHED Data infographic