Background Prehospital research may require ambulance clinicians to randomise patients in time-critical circumstances, while physically remote from senior support available in other clinical settings. In the PACKMAN randomised controlled trial of ketamine versus morphine, both participating ambulance services permitted newly-qualified paramedics (NQPs - within 2 years of registration) to enrol to the study after completing relevant training, as they would be expected to use the study intervention, were it brought into clinical practice. There is currently limited evidence around the NQP role and any possible link with research participant safety.

Methods We conducted an analysis of the NQP contribution to enrolment, to include review of protocol compliance and safety events, broken down by post-registration period of the paramedic: NQPs (<2 years) or experienced paramedics (>2 years). Both ambulance services provided the following data: trained paramedic numbers, enrolled participant numbers, adverse events and serious adverse events (SAEs), and protocol non-compliances.

Results 142/459 (31%) of study-trained paramedics were NQPs. 117/303 (38%) of participants were enrolled by NQPs (recruitment ongoing). Of participants enrolled by NQPs, 43.6% experienced an adverse event, versus 44.4% of participants enrolled by experienced paramedics (OR 0.96 [0.59 to 1.59]; p=0.893). 2.6% of all NQP-enrolled participants experienced an SAE, versus 2.2% of all those enrolled by experienced paramedics (OR 1.14 [0.16 to 6.9]; p=0.861). Protocol non-compliances were 4 (3.4%) in NQPs and 1 (0.6%) in experienced paramedics (OR 6.27 [0.61 to 310.21] p=0.063).

Conclusion Newly-qualified paramedics made an important contribution to this study, both in terms of patient enrolment, but also in improving the generalisability of study findings across the ambulance setting. We found similar levels of adverse events in NQP versus experienced paramedics. Both serious adverse events and protocol non-compliance were infrequent. We found no evidence of safety implications to including NQPs in this trial. Study training and participation were optional; different considerations may apply for research where participation is mandated.