Background Since 2008, Britain has been developing trauma networks, and ambulance services have been adopting triage tools to support these. So far there has been no published work on how UK paramedics use these algorithms. This study aims to evaluate factors affecting accuracy and self-perceived confidence of paramedics from one UK Ambulance Trust when applying the Major Trauma Decision Tree (MTDT).

Methods A quantitative cross-sectional survey design was used; a questionnaire sent to every paramedic within one Trust. The questionnaire asked for basic demographic data, then describing four case studies. Respondents applied the MTDT to the case studies, stating which algorithm steps (if any) they triggered, and their appropriate destination. Finally, a Likert scale explored respondent views on the MTDT. Descriptive and inferential statistics were used to look for any linked factors affecting accuracy/confidence.

Results Population N=1,132, sample size n=178 (response rate=16%). Sensitivity with the MTDT was 77% (95%CI 72%–81%), specificity 61% (95% CI 56–66%). The trigger most commonly missed was patient age >56. Respondents reported transport time to MTC/TU influencing algorithm compliance.

Self-perceived confidence was low. Self-reported exposure to trauma correlated positively with confidence (rs [178] =0.323, p<0.0005). Respondents' concerns about reception received from hospital staff showed significant negative correlation with confidence (rs [178] =−0.459, p<0.0005).

Conclusion Respondent sensitivity was low. Paramedic concerns about transport time are prevalent and could affect sensitivity. The most commonly missed trigger was age. Future training may benefit from addressing these points.

Respondents' confidence with the MTDT was low. Confidence was closely linked with exposure to trauma, and the reception anticipated from hospital staff.