MR1376 - OHCAO (Out of Hospital Cardiac Arrest Outcomes)

The University of Warwick requires Civil Registration Mortality and Demographics data for the purposes of the Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) project.

Improving patient outcomes from out-of-hospital cardiac arrest (OHCA) is a significant public health issue in the UK and a key priority for the NHS. Every year there are nearly 40,000 OHCAs where resuscitation is commenced or continued by paramedics. Typically, less than 10% of OHCA patients survive to hospital discharge.

To identify the key characteristics contributing to better outcomes in some ambulance services, reliable and reproducible systems are needed to be established for collecting data on OHCAs in the UK.

The British Heart Foundation (BHF) and the Resuscitation Council UK (RCUK) funded the development (and continued management) of the Out of Hospital Cardiac Arrest Outcomes (OHCAO) registry collecting data from ambulance services on all emergency medical services (EMS)-resuscitation attempted OHCA patients to support a structured research programme. It is hosted and managed by the Emergency Prehospital Perioperative & Critical Care (EPPiC) group at Warwick Clinical Trials Unit, University of Warwick.

The OHCA registry will help identify the epidemiology and outcome of OHCAs; explore sources of variation in outcome; help identify best practice and improve patient outcomes for those suffering an OHCA.

Robust and reliable data are required to measure the disease burden, identify factors that influence survival, and assess treatment and care protocols supporting continuous quality improvement efforts. If OHCA outcomes are not measured it is difficult to gauge performance and there is a lack of a reference point to determine the impact of any implemented quality improvement efforts.

Prior to the OHCA registry, a national surveillance system for OHCAs did not exist. Each ambulance service collects information but only for audit purposes. A national registry allows for more reliable and accurate data aggregation, enables benchmarking and continuous quality improvement initiatives.

This Agreement concerns the part of the OHCAO project which aims to standardise and streamline the process for outcome verification for patients who did not die in the care of the ambulance services, to determine whether these survivors died subsequently. The OHCAO registry is only able to collect data on short-term outcomes from ambulance services. An objective of the OHCAO project is to explore mortality rates at longer-term for OHCA survivors. Linking to Civil Registration mortality data, which is a single, accurate and reliable source for mortality, is the best way to achieve this.

The objective under the previous version of this Agreement was to test the feasibility of improving the registry data, increasing the match rate with Civil Registration Mortality to enable an analysis of 30-day mortality. The feasibility study did improve the match rate for linkage and the resulting data set was used to analyse 30-day survival from OHCA.

The OHCAO registry is used to inform and support national OHCA strategy and NHS England’s 10-year plan for OHCA to improve OHCA survival. Warwick Clinical Trials Unit plans to link the whole registry data set in the same way as before and in addition add mortality beyond 30 days and cause of death data and to do this on an ongoing basis. Collecting data on long-term survival is important as it will

- address a current knowledge gap;

- feed into national OHCA strategy;

- enable an evaluation of and assessment of how to address unwarranted variations, monitor temporal trends, and

- allow evaluation of factors associated with longer-term mortality among survivors of OHCA in the UK.

As a result of the above the current objectives are to link on an ongoing basis all OHCA patients not confirmed as being dead at hospital transfer to NHS patient demographic data and Civil Registration mortality data through NHS Digital in order to:

- improve completeness of NHS number data in the OHCAO registry for future data linkage;

- use updated date of birth and postcode data to clean data in the OHCAO registry;

- establish cause, fact and date of death for those OHCA patients not confirmed as being dead at hospital transfer but who died subsequently;

- retrospectively confirm OHCA survival beyond 30 days (1 year, 2 year, etc.) to enable calculation of longer-term survival;

- track (flag) on an ongoing basis those patients still alive to confirm data of death to enable calculation of longer-term survival.

All patients from the OHCAO registry who are not confirmed as deceased will be flagged on NHS Digital’s system so that, on an ongoing basis, NHS Digital can provide reports of their vital status and, where deceased, their cause of death to enable analysis of longer-term survival.

This linkage programme will:

1. Improve the completeness and quality of variables used for case matching collected by the Ambulance Services by:

a. Improving completeness of NHS number data in the OHCAO registry for future data linkage;

b. Using updated date of birth and postcode data to improve the accuracy of data clean processes;

c. Establishing cause, fact and date of death for those OHCA patients who were not confirmed as being dead at hospital transfer.

2. Improve the quality and completeness of mortality data collected by the Ambulance Services through linkage with Civil Registration mortality data.

3. Use the resulting data set to analyse survival outcomes from OHCA.

The University of Warwick is the sole data controller for the personal data shared with and received from NHS Digital under this Agreement.

The legal basis for processing personal data is GDPR Article 6(1)(e) – a public task.

The legal basis for processing special category personal data is GDPR Article 9(2)(j) - 'processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes...'.

No organisations other than the University of Warwick will process the data.

The project is overseen by a Steering Committee comprising of representatives from the funders (BHF and Resuscitation Council (UK)), the co-ordinating centre (University of Warwick), Ambulance Service Medical Directors, representatives of the Ambulance Service Chief Executives, representatives of Ambulance Service Audit Committee, patient/user representatives and other partners. The committee is chaired by an individual from Resuscitation Council (UK). The nature of the Steering Committee’s role is advisory and it informs decisions taken by the University of Warwick in respect of the data.

The University of Warwick will make bespoke subsets of data from the OHCA registry available to external researchers whose applications for data access are approved by the OHCAO Academic Committee, which is made up of members of the OHCAO Steering Committee. No data from NHS Digital will be shared with third parties. Subject to the OHCAO Academic Committee’s approval, which will take account of the necessity for the data, the University of Warwick may share variables derived from the NHS Digital data. Such variables are limited to:

• Vital status (alive or deceased)

• Whether the cause of death was cardiac arrest (yes or no)

• Survival status at 30 days, 12 months and every subsequent 12 months until death after cardiac arrest (alive or deceased)

• Place of death (hospital, care home or other)

No information which would identify a patient will be shared. Date of birth and date of death will not be shared.

Ambulance services collected information during the course of their routine duties. Information about individuals who receive resuscitation for cardiac arrest is securely transferred to the Warwick Clinical Trials Unit (CTU), University of Warwick.

The Warwick CTU will supply to NHS Digital identifying details of the existing cohort of between 150,000-200,000 people. The following variables will be supplied:

a. Patient forename and surname

b. NHS Number

c. Post Code

d. Date of birth

The cohort will be flagged on NHS Digital’s system and NHS Digital will provide an initial report of latest demographics information and, for all deceased patients, mortality information. NHS Digital will provide subsequent reports every 6 months. From the demographics dataset, latest NHS Number, Postcode, Date of Birth and Date of Death (if applicable) will be supplied. This will be used to confirm the accuracy of the OHCAO dataset and provide any missing variables to support future data linkages.

Every 12 months the Warwick CTU will submit identifying details for another cohort of approximately 10-15,000 new cases for the same service as described above.

Once details of a patient’s death has been reported, the deceased patient will be removed from the cohort held on NHS Digital’s system.

The Annual Epidemiology reports are published at the end of the year and report the previous year’s data (e.g. 2019 data will be published in December 2020). Therefore, the cohort details will be submitted in July/August each year to coincide with the annual data cleaning processes and data will be received in September/October to allow enough time to have the most up to date survival data for the Annual Epidemiology Reports.

The Warwick CTU will use the mortality data to calculate survival outcomes on a six-monthly basis.

The data set will be held securely and the University of Warwick’s secure network. All servers are located in a purpose built data centre protected by a strictly policed access control system and CCTV surveillance. Access to all systems requires a user name and password. Access to the database application requires an additional security role to be assigned to lock down features of the application to only those users who require them e.g. access to personally identifiable data.

The raw data received will be kept in its own encrypted folder separate from the OHCAO registry to allow complete data deletion (i.e. no footprint) at the termination of the data sharing agreement.

Derived data points will be created and added to the research registry to report long-term survival from OHCA. New variables including fact of death at 30 days, 12 months and every subsequent 12 months until death will be created from the raw data. A new derived variable will be added to the research registry to include the cause of death data.

The data set will be used to improve the accuracy of the OHCAO data base variables for NHS Number, Post Code, Date of Birth and Date of Death and used to update the database where necessary.

The new derived data points will be added to the list of variables within the OHCAO research registry that can be shared as part of a pseudonymised subset with external researchers subject to approval by the OHCAO Academic Committee and under a data sharing agreement between the University of Warwick and the external institution.

The following members of the OHCAO team will have access to the raw data:

Study Manager, Research Database Manager and Study Statistician to complete data cleaning and create derived data sets for survival outcomes.

The Study Assistant Professor and Data Analyst will have access to the derived data sets and updated demographic data.

The NHS Numbers have been requested to allow for potential future data linkage projects. Datasets which the University of Warwick may, in the future, look to link with the OHCAO registry include Hospital Episodes Statistics (HES), Myocardial Ischaemia National Audit Project (MINAP) and Intensive Care National Audit and Research Centre (ICNARC). Any such linkages are outside of the scope of this Agreement and a subsequent amendment would need to be approved prior to any linkage taking place.

The continuing data linkage between the OHCAO registry and NHS Digital will provide the most up to date and accurate survival outcome data and this will be used in the following outputs:

1. Annual OHCAO Epidemiology Report - This is a summary report of the annual OHCA data contributed by the Ambulance Services to the OHCAO registry. It presents an overview of the results of the epidemiology of cardiac arrest, benchmarked against national data where possible and the data completeness for key variables collected (data quality). The report is for a wide audience and is published on the OHCAO website. Next publication February 2021 (2019 data) and the 2021 publication (2020 data) is expected around February 2022.

2. Annual Epidemiology Report for each individual Ambulance Service - This is a summary report of the annual OHCA data contributed by each Ambulance Services to the OHCAO registry. It presents an overview of the results of the epidemiology of cardiac arrest, benchmarked against national data where possible and the data completeness for key variables collected (data quality). This report is not published publicly and is created for Clinical Audit and Medical Directors at each Ambulance Service. Next publication February 2021 (2019 data) and the 2021 publication (2020 data) is expected around February 2022.

*The difference between the two reports listed above is that the audience for the Annual OHCAO Epidemiology Report is members of the public. It provides national average summary data for the whole registry. The Annual Epidemiology Reports for each Ambulance Service are similar but report data for the individual ambulance service in relation to the national average. These reports are produced for the ambulance service medical directors and policy makers and are not publicly available.

3. Peer reviewed epidemiology of OHCA papers analysing long-term survival outcomes - Aggregated data published in peer-reviewed journals (e.g. resuscitation). Journal articles will be open access for academic and scientific community. These are likely to be published on a 5-year basis with the first planned for 2021.

4. Presentations of long-term survival outcomes analysis - Aggregated data to be presented at European Resuscitation Council 2021.

Long-term survival from OHCA is a key area of research that is needed and must be addressed in analysis to improve the patient pathway. Continued data linkage with NHS Digital will allow for this to research to take place. Reliable survival data will enhance the value of the registry as a research and quality improvement tool. Continued data linkage with NHS Digital is expected to lead to:

1. OHCAO registry – data linkage programme will provide a more robust and high quality national OHCA data set. Improved demographic data (completeness of NHS Numbers) will facilitate further data linkage to support a better understanding of the full patient pathway for cardiac arrest (prevention, event, recovery, rehabilitation), e.g. linking to Hospital Episodes Statistics to collect patient data on pre-arrest hospital attendances and co-morbidities, and post-arrest hospital treatment (percutaneous coronary intervention, targeted temperature management).

2. OHCA research literature – will add to OHCA research literature, specifically reporting on long-term survival from OHCA in the UK, on which there is currently no published data. Published papers will contribute to international knowledge on OHCA and initiatives to improve outcomes. The additional data will allow for the OHCAO team to publish papers that will inform policy makers, service providers, clinicians and researchers in the UK and internationally about trends in the epidemiology and outcomes from OHCA in the UK. The aim is to publish long-term survival analysis during 2022.

The expected benefits of the above are improvements to patient care and outcomes. Analysing long-term survival will provide monitoring information useful to monitoring improvements designed to reach targets for national OHCA strategies (e.g. as specified in the NHS England 10-year plan), which in turn impacts on patient care and outcomes.

The success of and need for the OHCAO registry is highlighted in the NHS England Long Term Plan. Being able to provide the best quality survival data has helped inform NHS England policy. The registry will also be able to monitor progress toward the target of saving an additional 4,000 lives a year by 2028.

The Annual Epidemiology reports provide valuable information to ambulance services allowing bench marking with the national average. The reports are also used in planning their services and resources towards quality improvement initiatives. The impact of these initiatives can be measured using OHCAO registry data.

The OHCAO research registry is a valued research tool used by the clinical and academic community. Data sharing applications with internal and external researchers continue to increase each year. Use of the data by external researchers will result in increased information to contribute to the above aims.