Background Head injury results in a high use of emergency services, although most people with head injuries do not require hospitalisation. Conversely, some evidence suggests that lay recognition of the seriousness of head injury can be problematic, for example in sports settings.

Aim To investigate how members of the public - parents of young children, school staff, sports coaches, informal carers of older adults, young adults and other adults - understood head injury terminology and when an emergency ambulance/999 call was required for head injury, against UK public guidance.

Methods A mixed methods exploratory study, comprising of electronic and paper self-completion surveys across the UK and focus groups or interviews. Survey data were analysed statistically against the outcomes of understanding of terms and selection of the correct action by symptom. Focus group/interview data were analysed thematically.

Results We received 520 survey responses, with respondents from across gender, age group, ethnicity and first aid experience. Out of 19 given signs and symptoms of head injury, participants could differentiate the most serious (e.g. unconsciousness 92% call 999) from those that could be observed (e.g. nausea 5%, and altered behaviour 5–30% call 999). The proportion of ‘correct’ actions ranged from just below half to almost 100%. Those aged 18–24 had a lower percentage of correct answers. Focus groups and/or interviews were held with 44 participants. Hypothetical scenarios elicited a range of responses, from calling 999 in any instance, to not calling in serious situations. Participants described ‘life experience’ as influential in the decision whether to call 999 or feel confident to observe.

Conclusion Distinguishing severity of head injury was reported as difficult and confidence about the best course of action was low. The study was limited by regional recruitment biases, but supports the need for public health guidance in head injury.