TRIM: What Triage Model Is Safest & Most Effective For The Management Of 999 Callers With Suspected COVID-19? A Linked Outcome Study

Ambulance services cannot and should not attend and convey every patient with COVID-19 symptoms to hospital. There are two stages of triage: to decide 1) who to dispatch a response to, for face-to-face assessment and care; and 2) who to convey to hospital. This triage is key to identifying people who need to be treated in hospital. Under-triage will result in patient harm, in this case, avoidable serious illness and deaths. Over-triage will result in unnecessary conveyance to the Emergency Department, exposing patients to risk of infection, diverting resources from those in need and overburdening already pressurized services.

Different triage models are used by different ambulance services, and are changing over time as call patterns and understanding of the pandemic evolve. It is not clear which of these approaches (if any) works best, or which elements lead to a successful triage model.

TRIM (“What TRIage model is safest and most effective for the Management of 999 callers with suspected COVID-19? A linked outcome study”) will investigate these models by looking at outcomes for 999 callers in four ambulance services during the first wave of the pandemic (March to August 2020). These ambulance service areas are the East of England Ambulance Service, the East Midlands Ambulance Service, the West Midlands Ambulance Service, and the Yorkshire Ambulance Service.

TRIM is a stand-alone research project funded by the National Institute for Health Research and UK Research and Innovation joint COVID-19 rolling funding call in June 2020. It is not part of a wider or ongoing programme of work or collaboration.

The primary study outcome is the proportion of patients conveyed to hospital (i.e. those who are conveyed and then admitted). Study outcomes will also consider further 999 calls; emergency department presentations; hospital admissions; intensive care unit admissions; and mortality. All outcomes are assessed at 1 month and 3 months following the initial contact.

TRIM will look at patients admitted to hospital with suspected or confirmed COVID-19, and check whether they made a 999 call in the preceding 7 days. This will provide data on any missed opportunities and under-triage.

The research team at Swansea University hope that, by identifying which triage models were most successful, future policies and practices can be better informed during the current and future pandemic situations.

Swansea University recognise that the pandemic response has evolved since TRIM was funded in June 2020, the initial enquiry to NHS England in December 2020, and also since the original application was submitted to NHS England in September 2021. However, it is still useful to review the circumstances of this unprecedented scenario, and whether there are any lessons that can be learnt. In that regard, Swansea University believe it is critical that these lessons are learnt based on recent experience, in the event of any future pandemic situations. While it is impossible to accurately assess the broader relevance of research findings until Swansea University have conducted the statistical analysis, Swansea University anticipate the evidence will still be useful in a broader sense - for example, in the context of peak 999 call times or winter pressures.

Study sites and PPI representatives remain engaged and active research partners in the TRIM study, and are keen to see the results of the work that have already been undertaken (e.g. in preparing the ambulance service data).

DATA SUMMARY

The data requested from NHS England includes information on mortality, hospital attendances and admissions for 3 months following the initial contact with suspected or confirmed COVID-19. This will identify which people were at greatest risk from their suspected COVID-19 infection, and therefore should have been conveyed to hospital. The data requested will also identify which patients were brought to hospital and immediately discharged, and therefore may have been safe to leave at home. This data is crucial to understand whether ambulance service triage models successfully managed this patient group. Swansea University have applied for and received Health Research Authority (HRA) Confidential Advisory Group (CAG) approval (Reference - 21/CAG/0106) under section 251 of the NHS Act 2006 as a valid legal basis to cover the linkage and flow of patient identifiable data without consent.

Pseudonymised record-level data is required. A Study ID will be used to link hospital attendance and mortality data from NHS England with ambulance service 999 calls and ambulance dispatch data. This will provide a complete picture of NHS contacts following the initial contact with suspected COVID-19 and therefore whether patients were under- or over-triaged.

Data obtained for TRIM through this Agreement will only be used for TRIM and will not be utilised in any other research project. This is also true for 999 call and ambulance dispatch data obtained for TRIM directly from the East of England Ambulance Service, the East Midlands Ambulance Service, the West Midlands Ambulance Service, and the Yorkshire Ambulance Service.

Swansea University are requesting access to the following datasets from NHS England:

Emergency Care Dataset (ECDS): Date; reason for contact (COVID/not); outcome of presentation; admission date (where applicable). This will provide data on the outcomes of patients brought to hospital by ambulance, including whether they were admitted to hospital or discharged home. Patients who were not conveyed may also present themselves to hospital. It is vital to understand the proportion of those who do, and whether they were admitted, as this is a key indicator of cases that were under-triaged.

Hospital Episode Statistics for Admitted Patient Care and Critical Care: these datasets will provide data on whether the initial contact was admitted to hospital within the follow-up periods; reason for and length of stay; and outcome of stay and discharge date. This will support the ECDS data in identifying whether patients were appropriately triaged or not.

Civil Registration (Deaths): Date of death will indicate whether any given death falls within the 1 month and 3-month follow-up period. It will also allow survival curves to be generated, showing the proportion of patients who survive for at least N days, where N is the number of days following triage, for the whole follow-up period and how this varies by study arm. Cause of death will indicate whether the death is COVID-related or not for subgroup analyses.

The Civil Registration (Deaths) product does not allow for data to be filtered to a specific time period, as requested by Swansea University. Swansea University will therefore be supplied with all mortality data relating to the cohort submitted. They will however be required to delete all data which does not fall within the specified period - 3 months after each patient’s initial contact for the period 1 March 2020 – 30 November 2020.

DATA MINIMISATION

The data requested covers the period of the first wave of the COVID-19 pandemic (March – August 2020) plus 3 months follow-up. This means the full dataset must span the period 01-March-2020 to 30-November-2020. Data outside this period are not required.

The data request is limited to the areas covered by the four participating ambulance services (East of England Ambulance Service, East Midlands Ambulance Service, West Midlands Ambulance Service, and the Yorkshire Ambulance Service). Data outside these areas are not required. A wide geographical spread is necessary to capture the richness of data on triage models used during the pandemic, and to make sure that any conclusions regarding triage models are broadly applicable to the rest of England and Wales. Although the data requested is restricted to England only, due to the similarity of the triage systems and processes employed in Wales, Swansea University expect findings to be applicable to Wales as well.

The study cohort is estimated to be around 80,000 people, however this is neither a target nor a cap – all callers who meet the above criteria will be included. It is anticipated that the number of 999 callers will be similar in each ambulance service area. It is not viable to perform this research without relying on routinely collected data. Patient level data is required to determine whether each 999 caller was appropriately conveyed to hospital or not.

Data cannot be narrowed by demographics as the coronavirus pandemic affects people of all backgrounds. Demographic factors, including age, sex, and ethnicity, are likely to be important in the triage, management, and outcomes of people with suspected COVID-19, particularly where they relate to an increased chance of death.

People will only be included in the study cohort if they called 999 and were flagged as having suspected or confirmed COVID-19, or were admitted to hospital with suspected or confirmed COVID-19. All-cause mortality data will be considered in the analysis, as well as COVID-specific mortality. Date of death is required to determine if the death fell within a 3-month follow-up period after the initial 999 call or hospital admission with suspected COVID-19.

There is no control group as this is not possible. Instead, the four ambulance services will be compared with each other to investigate which triage system gives the best outcomes for patients.

All patient episodes in the requested datasets are required to understand what happens to patients following their initial triage for suspected COVID-19. Patient outcomes may not be known for some time after the initial triage, and patient's conditions may change over time.

LEGAL BASIS FOR PROCESSING

Data is processed under UK GDPR Article 6 (1) (e) – task in the public interest. Correct triage models for 999 callers in an unprecedented pandemic situation is of vital interest to patients, attending practitioners, ambulance services, and the wider NHS. To this end, the study meets the conditions outlined in Schedule 1 Part 1 (4) of the Data Protection Act 2018. TRIM is led by an experienced team from Swansea University, a leading UK medical school and research institution. Swansea University is a public authority as outlined under Schedule 1 of the Freedom of Information Act 2000. Power is conferred upon Swansea University by the terms of it’s Royal Charter “to provide schemes of study by teaching and by research”.

Special categories of data are processed under UK GDPR Article 9 (2)(j) “…scientific or historical research purposes or statistical purposes…”. The special categories of data requested are health data, age in years, gender, ethnicity, and index of multiple deprivation decile. Any/all of these factors may be important indicators of which patients should or should not be conveyed to hospital with suspected COVID-19.

ETHICAL/MORAL CONSIDERATIONS

Ethical considerations include the use of patient data without consent. As the estimated cohort size is around eighty thousand it is not viable to seek consent from this many people in a timescale that would produce useful results (within the current pandemic). As aforementioned, Swansea University have applied for and received Health Research Authority (HRA) Confidential Advisory Group (CAG) approval (Reference - 21/CAG/0106) under section 251 of the NHS Act 2006. This provides a legal basis for Swansea University to link and flow patient identifiable data without consent. Patient objections will automatically apply to this data request.

The use of routine data is also the least intrusive and most reliable way to carry out the research. Many patients with COVID-19 died, and others may still be suffering longer-term effects. They may also be hospitalised from subsequent waves of the virus. Therefore, following up patients directly is likely to be more distressing than the use of routine data. Direct follow-up would also be subject to recall bias and large volumes of missing data.

PPI ENGAGEMENT

A Patient Advisory Panel was set up as part of this research study to offer lay insight into the research. The group comprises PPI contributors, who were recruited via advertisement. Interested individuals submitted expressions of interest to join the group. No specific experience was required although an interest in health services research was recommended. All aspects of the methodology have been discussed with the group and they are supportive of the research approach adopted, understanding that the use of routine data is a reliable way and unintrusive way to undertake the research and that it would not be possible to undertake the study using other methods. Separate Privacy Notices and Patient Notification Leaflets have been created in collaboration with the Patient Advisory Panel. The Patient Advisory Panel meets quarterly and advises the Research Management Group. Two members of the Patient Advisory Panel sit on the Research Management Group. One of these members has provided a letter (supplied to NHS England), confirming their involvement in the study design and ongoing support for this research approach.

DATA CONTROLLERSHIP

Swansea University is the sole research sponsor and data controller who will also process the data for the TRIM study.

A research management group consists of study co-applicants and representatives of research stakeholders. This includes members of the East of England Ambulance Service; East Midlands Ambulance Service; West Midlands Ambulance Service; Yorkshire Ambulance Service; the Welsh Ambulance Service; methodologists from the University of Stirling; Kingston University and St George’s, University of London; University of Lincoln; and public representatives.

The research management group is not a decision-making body. Members of the research team based in ambulance trusts have identified the study cohorts within the trust catchment areas and facilitated data submission to NHS England. They will not be involved in the analysis of the routine data but will contribute to interpretation of findings. Other members of the research team, including those based at other universities, will not be involved in the analysis of the routine data, but will contribute to interpretation of findings and assessing implications for policy and practice. In line with Health Research Authority (HRA) and Information Commissioner's Office (ICO) guidance, the research management group and their respective organisations (with the sole exception of Swansea University) are neither data controllers nor data processors with regards to this Agreement and will only be able to access aggregated outputs with small numbers suppressed in line with the HES analysis guide.

TRIM is funded by the National Institute for Health Research (NIHR) and UK Research and Innovation (UKRI) joint COVID-19 rolling funding call. Neither the NIHR nor UKRI have any involvement in study management, data analysis, or interpretation of findings. The NIHR and UKRI are neither data controllers nor data processors in regard to this Agreement.

Data processing will only be carried out by substantive employees of Swansea University (the sole data controller) with appropriate training in data protection and confidentiality.

The cohort file to be submitted to NHS England for linkage is split into two: (1) ‘forwards’ cohort: linking 999 data from selected ambulance services with NHS England datasets for patients logged with COVID-19 symptoms; (2) ‘backwards’ cohort: linking hospital data from selected hospitals for patients who were hospitalised, admitted to Intensive Care Units / Intensive Therapy Units or died with a confirmed diagnosis of COVID-19 with 999 data to establish whether the patients called 999 prior to hospitalisation, whether they were logged with suspected COVID-19 and what the outcome of the call was.

Patients in the hospital admission sub-cohort (backwards) will be identified by clinicians in each participating hospital. Swansea University are interested in outcomes for 999 callers who were hospitalised but not conveyed, as these represent under-triage, and whether those calls were classified as suspected/confirmed COVID or not. Linked data for patients who did not call 999 are not required. The participating hospitals, and their corresponding ambulance services are: Norfolk and Norwich Hospital (linked to East of England Ambulance Service); Queen’s Medical Centre, Nottingham (linked to East Midlands Ambulance Service); Sandwell and West Birmingham Hospital (linked to West Midlands Ambulance Service); Northern General Hospital, Sheffield (NGH, linked to Yorkshire Ambulance Service (YAS)); and Sheffield Children’s Hospital (linked to YAS). The participating ambulance trusts will receive record-level, identifiable data for patients admitted with suspected COVID-19 from the corresponding hospital in their area.

Once identifiable data for these patients has been transferred to the participating ambulance trusts, a research paramedic from each trust will search the ambulance service database for any 999 calls made by those patients in the preceding 7 days. A large overlap between these two groups is anticipated. Those patients will then be added to the ambulance service cohort file for transfer to NHS England. This group will be used to identify sub-cohorts who were under-triaged by the ambulance service.

The 999 call sub-cohort (forwards) will be identified by research paramedics in each of the four participating ambulance trusts. This will be carried out by a search of 999 calls and patient clinical records for cases classified as suspected COVID-19, or for symptoms consistent with COVID-19.

The cohort identification file will then be imported into NHS England where the data will be used to identify hospital records and mortality data for the three months following the initial contact with suspected COVID-19. The study cohort file transferred from the four ambulance services contains record-level identifiable data. No other data will be transferred to NHS England.

Data items will include: study ID; name; NHS number; date of birth; postcode; and the date of the first such 999 call or admission within the study period. The estimated cohort size is 80,000 records.

Data disseminated by NHS England will be record-level pseudonymised data. It will include: study ID; demographics (age in years, gender, ethnic group, and English index of multiple deprivation decile); the date, reason for, and outcome of any Emergency Department attendances, hospital admissions, and Intensive Care Unit admissions; diagnosis of COVID-19 (including date of diagnosis); and mortality (date and cause of death).

Data from NHS England will be imported into the UK Secure e-Research Platform (Swansea University) where it will be linked with 999 call and ambulance dispatch data using study ID for analysis. Study sites have a list linking study IDs and identifiers, but Swansea University will not have access to this list. Data will not be relinked to it, or otherwise made re-identifiable. 999 call and ambulance dispatch data will be provided by the four participating ambulance trusts. They will send record-level pseudonymised data directly to Swansea University. This file will include study ID; the date (treated as index date), reason for, and outcome of any 999 calls and ambulance dispatches for patients in the cohort.

999 call and ambulance dispatch data will determine (1) the severity of the initial call and (2) any subsequent calls or dispatches made for this patient. This will indicate if the patient’s situation worsened, or if the patient did not believe they were triaged appropriately in the first instance.

In addition to the data flow into and out of NHS England described above; research paramedics at the East of England Ambulance Service, the East Midlands Ambulance Service, the West Midlands Ambulance Service, and the Yorkshire Ambulance Service will run a second search for any other events for the study cohort in the 3 months following their initial contact with COVID-19 (covered by CAG approval). Any such events will be included regardless of whether they are COVID-related or not. These data will be transferred securely to Swansea University and imported into the UK Secure e-Research Platform, where they will be linked with the data from NHS England to form the analysis dataset.

The UK Secure e-Research Platform is a safe, secure and controlled environment for data sharing, linking and analysis accredited to ISO 27001 standards. It is accessed via a two-factor authentication process involving a unique username and password, and individually issued Yubikey device. The Yubikey device is a hardware authentication device which protects access to computers, networks, and online services. User accounts are only given to authorised researchers with appropriate training in data protection and confidentiality. Access to specific projects is restricted to authorised users working on that project. The remote desktop environment has built-in measures to protect data including logging all user activity; restricting internet access; and preventing all data exports without approval.

There will be no subsequent flow of record-level data and no record-level data will be allowed to leave the UK Secure e-Research Platform. There will be no attempt to re-identify individuals. Data will be only processed on the UK Secure e-Research Platform. All study outputs, and findings from the statistical analysis, will be aggregated data with small numbers suppressed in line with the HES analysis guide.

No-one outside the East of England Ambulance Service, East Midlands Ambulance Service, West Midlands Ambulance Service, or Yorkshire Ambulance Service will have access to any list linking study IDs to identifiable people. Only the data analysis team at Swansea University, which does not overlap with the ambulance services, will have access to NHS England data.

Study outputs hope to include:

- A final study report submitted to the funder, National Institute for Health Research (NIHR). This hopes to be published online alongside the study protocol on the NIHR website (https://www.nihr.ac.uk/), researchfish (https://researchfish.com) and/or the UK Research and Innovation (UKRI) Gateway to Research (https://gtr.ukri.org/).

- Peer reviewed papers submitted to open-access scientific journals such as the BMJ Open (https://bmjopen.bmj.com/).

- Abstracts, posters, and presentations at conferences, such as the Health Services Research UK conference (https://hsruk.org/conferences), hope to be submitted on an ad hoc basis.

- Non-technical summaries and presentations hope to be distributed to the East of England Ambulance Service, the East Midlands Ambulance Service, the West Midlands Ambulance Service, and the Yorkshire Ambulance Service.

Any study outputs will be presented as aggregated figures with small numbers suppressed in line with the HES analysis guide.

Dissemination seeks to maximise stakeholder interest and understanding of the study and its outputs to maximise impact on ambulance service policy and practice. It aims to build on the research management group’s profile and reputation with previous studies focused on improving the quality of prehospital care. The research management group has and intends to continue to work with public contributors and co-applicants to develop a study communication plan. This plan aims to include an assessment of stakeholder needs and hopes to set out communication activities and milestones. It is anticipated to look to include engagement with patient and professional groups, NHS managers, commissioners, and policy makers. It is planned that plain English summaries will be produced where appropriate.

The target audience for dissemination includes policy makers, care-commissioning bodes, ambulance service providers and the general public.

The research management group hopes to use strong existing links with ambulance services directly, and through national bodies such as the National Ambulance Research Steering Group, National Ambulance Services Clinical Quality Group, the Association of Ambulance Chief Executives and National Ambulance Services Medical Directors.

Swansea University hope to disseminate key findings to front-line ambulance service staff via internal ambulance boards, service briefings and bulletins, and practitioner/professional publications.

The study communications, publications and dissemination plan may include media engagement such as written press coverage, online media, and social networking. Media/networking engagements hope to be via PRIME Centre Wales, the National Ambulance Research Steering Group (http://narsg.uk/), the 999 EMS Research Forum, HSR UK and similar online/face-to-face events/conferences, in addition to any others proposed by members of TRIM’s Patient Advisory Panel/Research Management Group/Study Steering Committee. This would be supported by the dedicated marketing team in Swansea University Medical School. In addition to the full study report, TRIM intends to produce an executive summary to disseminate through the Wales Centre for Primary and Emergency (including Unscheduled) Care Research network (http://www.primecentre.wales/#:~:text=Read%20the%20PRIME%20Centre%20Wales,research%20proposals%20and%20support%20researchers.). Researchers may present study findings at appropriate national and international events and will aim to ensure that wider learning from the study is disseminated to appropriate audiences.

TRIM does not include the development of any algorithms, tools, technologies, or similar. While TRIM seeks to identify which triage models lead to better outcomes of patients with suspected COVID-19, it does not seek to develop new triage models. Therefore, no exploitable intellectual property is anticipated. Should any be developed, the research management group will seek professional advice from the Research, Engagement, and Innovation Services at Swansea University.

Authorship of all reports, scientific papers, and other publications will be in line with a pre-specified authorship agreement. This will be prepared in line with the International Committee of Medical Journal Editors guidelines (http://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html).

The research funding bodies will be acknowledged within any and all publications and presentations.

A paper comparing patient outcomes associated with each triage model is targeted for the end of 2024. The final report to the funder is also due around this time. Conference abstracts, posters and presentations may be submitted on an on-going basis as opportunities arise.

The data from NHS England will not be used for any other purpose other than that outlined in this Agreement.

TRIM seeks to understand the triage of patients with suspected or confirmed COVID-19 during the first wave of the pandemic. It hopes to: produce evidence to enable comparison of the effectiveness and safety of triage models in place during the pandemic, both in the ambulance call centre and on-scene (key deliverable for this work package); provide evidence about effects on mortality, hospital and Intensive Care Unit/Intensive Therapy Unit admission and the accurate identification of serious COVID-19 infection; document implementation concerns; and inform decision making and policy guidance in future epidemics and pandemics future periods of acute high demand for ambulance services. Improvements in triage policies and protocols may help to: ensure that patients are treated in appropriate locations; reduce avoidable risk to practitioners; increase quality of care; and reduce pressure on hospitals.

If TRIM can help to identify the most successful triage system(s) for managing patients with suspected COVID-19, then this potentially allows UK ambulance services to improve the triage systems they use. Even if specific triage models cannot be replicated in every ambulance service area, it may be possible to identify common elements of successful triage models and implement them piecemeal. Given the extremely high volume of calls recorded for suspected COVID-19 during the pandemic, even a small improvement to triage systems may considerably improve overall patient outcomes.

TRIM’s PPI representatives and its Study Steering Committee believe study findings will have relevance despite the move to post-pandemic life and are keen that appropriate lessons from the pandemic are learned. More generally, improvements in triage systems are generally desirable - for example, appropriate triage may help to reduce ambulance waiting times outside hospitals, which has particular relevance given the recent Association of Ambulance Chief Executives report on ambulance queueing.

The cohort from four UK ambulance services within the first wave of the pandemic alone is estimated to be 80,000 people. A better understanding of the triage systems used, and their outcomes, could easily impact hundreds of thousands of people in the UK alone. Improving triage of this patient group may also free capacity to better help other patient groups. If study findings can be applied more widely, such as to winter flu pressures, this could lead to further and more sustained impact.

The benefits of this study hope to be felt firstly by the patients with suspected COVID-19 who are at the highest risk. It may also benefit low-risk patients, if they can be successfully managed at home, without the burden of a trip to hospital or the risks associated with that in a pandemic situation. These benefits will be equally applicable to future situations such as peak 999 call times and winter pressures. Finally, if a triage system is able successfully reduce the overall burden on the NHS during a pandemic situation, this would be to the benefit of practitioners in the ambulance service, and at receiving hospitals.

The study team hope to disseminate their findings on an on-going basis to be as timely and relevant as possible. Findings hope to be disseminated to relevant stakeholder groups – including all UK ambulance services - through executive summaries, scientific papers, and conference presentations.

Not stated in the register.