HIPPO: Health Inequalities in the PrehosPital critical care response to Out-of-hospital cardiac arrest

BACKGROUND: Cardiac arrest is a medical emergency when a person’s heart stops beating. Each year, NHS ambulance services treat around 32,000 people who have a cardiac arrest and sadly less than one in ten survive to leave hospital. The government aims to save an extra 1000 people’s lives per year from cardiac arrest.

A key factor affecting the chances someone will survive is how quickly the person receives emergency treatment. Community first aid with chest compressions and using a portable electric shock machine (defibrillator) can help, but the speed that healthcare professionals get there and provide advanced care is crucial to save the person’s life. The NHS response involves sending one or more paramedic ambulances to provide emergency treatment. In addition, ambulance services may send prehospital critical care teams with advanced skills to treat and then stabilise the patient.

Differences in the conditions in which we are born, grow, live, work and age can influence our opportunities for good health and are called health inequalities. Research has previously shown that health inequalities exist in how the public respond to cardiac arrest. People in deprived areas and areas with more non-white ethnicity residents are less likely to receive chest compressions from bystanders and are less likely to have a defibrillator located nearby. Efforts are being made to address this by the NHS and charities. There is a need to look at the NHS response to cardiac arrest and whether there is a need to improve in deprived and ethnically diverse areas.

AIM: This project aims to assess for health inequalities in the prehospital critical care response to cardiac arrest and see how the response could be improved.

DESIGN: The project involves four main pieces of work.

First, a review of published evidence will summarise the effect of prehospital critical care for cardiac arrest patients. This will look at the outcomes of patients who get a prehospital critical care response and compare them with those that receive the standard ambulance response. It will also summarise the published evidence of the types of team and the interventions provided.

Second, the research will compare the cardiac arrest patients that get prehospital critical care with those that don’t. This will see if ethnicity and deprivation status of neighbourhoods affects what care they receive.

Third, the research will look at where critical care team bases are and how long it takes them to get to different neighbourhoods. The response time will be compared to the neighbourhood characteristics, for example social deprivation and ethnicity. Also, it will see if this matches the neighbourhood cardiac arrest statistics, including the number of cardiac arrests and whether they receive community first aid.

Finally, the research will explore how we could use critical care teams to improve inequalities. To begin, we will bring together ambulance service leaders to understand how critical care teams are organised. After knowing what is realistically achievable, we will use computer models to see how the positioning of critical care team bases could change patient care. A final consensus conference of all stakeholders will decide how we could best improve inequalities.

Research funding until August 2026.

Retrospective data collection to end of December 2023.

Dr Adam Boulton

a.boulton@warwick.ac.uk