In England and Wales, the output from the study and the implementation meeting have been presented to the NHS England Clinical Reference Group for Emergency Preparedness and are being used to redesign the contents of the English mass casualty vehicles. Limitations Delphi studies are onerous tasks, both in terms of activity required and the duration of involvement. Consequently participant attrition is a known limitation, but often Inhibitors,research,lifescience,medical hard to accurately calculate as the numbers of people invited to participate are rarely reported. In this study only 32 (23%) of people invited to participate agreed and completed

data collection over the three rounds. The study required Inhibitors,research,lifescience,medical participants to complete two tasks, a rating of an item’s importance, and a quantification of how many of each item was required, instead of one. The former task is one for which Delphi method is well suited and traditionally employed; the latter arguably less so. This dual task and the sheer number of items to be rated (n=248) may have Inhibitors,research,lifescience,medical contributed to participant attrition during the study. Whilst this is disappointing, the actual numbers of participants who 4 mu completed all three rounds (n=32) is similar to other Delphi pre-hospital emergency care research [14,16]. Researchers

undertaking future Delphi studies in pre-hospital emergency care should aim to keep the number of items as manageable as possible, and estimate that they will need to invite approximately five times more individuals than the number they wish to participate.

Attaching two rating tasks per item, whilst feasible, is undesirable due to the potential negative effect this may Inhibitors,research,lifescience,medical have on participant retention. Only 54% of items reached consensus by the end of the study. This figure may have improved had further rounds of data collection occurred, but as the consensus between rounds two and three was not statistically significantly different, it is not very likely. Inhibitors,research,lifescience,medical In any case, the potential benefits of further data collection had to be balanced against the potential of participant fatigue and the potential of decreasing response rates [21]. Delphi studies accept participant responses at face value. As elsewhere [17] this study would benefit from further qualitative investigation to understand participants’ responses in greater depth. Terminal deoxynucleotidyl transferase Whilst the median quantities of items are a useful starting point for services planning their resources, these need to be considered together with the local context that the service is working in: urban settings may have a higher frequency of standard emergency ambulances with a base loading of equipment, whereas more rural environments will have different considerations and require to factor in the longer distances that patients will be travelling to hospital following treatment on scene.