Should a person have a cardiac arrest (where their heart stops beating) they require treatment of cardiopulmonary resuscitation (CPR). This includes providing chest compressions. Traditionally these compressions are provided by hand but mechanical chest compression devices (MCCD) have been investigated for use in out of hospital resuscitation attempts.

Research trials recruiting human participants have concluded recently. They all found no difference in survival outcomes when MCCD and manual compressions were compared.

Despite this, the latest expert review on MCCD suggests that MCCD can be a reasonable alternative to high quality manual compressions when these cannot be provided. MCCD continue to be used by Specialists in the local ambulance service and historically by those recruiting patients to a national multi centre trial of MCCD. There is another, as yet under-investigated element, and that is of ambulance crews' experiences of using such devices. Therefore it is a reasonable topic to investigate.

This study will invite local United Kingdom (UK) National Health Service (NHS) operational ambulance crews to participate in a 1-2 hour online focus group discussion (a collective group discussion) about their experiences of using MCCD. The participants will be any operational ambulance crew member, employed by the local ambulance Trust and who had experience of using any type of MCCD. The focus groups will be audio recorded; participants will be aware of this when they choose to participate.

The aim of this research is to collect and report ambulance crews' experiences of using mechanical chest compression devices for out of hospital resuscitation attempts.

Ultimately there may of course be benefits for patients by exploring whether MCCD play a part in out of hospital resuscitations. Funding has been offered by a manufacturer one of the types of MCCD; they have had no involvement in the design or analysis of the study.

Once transcribed, the data will be analysed manually. The content of each focus group will be coded and then each participants' individual responses will be coded, first using open coding, then focused coding to identify emergent themes, before concluding with the categories that have been identified. The constant comparison method of data analysis will be used.

Inclusion Criteria:

• aged 18 or over
• an employee of the local ambulance service
• employed as an operational ambulance crew member, irrespective of title
• to have experienced an out of hospital resuscitation where MCCD was used, irrespective of the type of device or their level of involvement.

Exclusion Criteria:

• not an employee of the local ambulance service
• have no experience of using a mechanical chest compression device at an out of hospital resuscitation
• the participant is unwilling to provide consent to participate
• the participant is unwilling to provide consent to be audio recorded.

Operational ambulance crew employees of the local ambulance service