Assessing consistency of the emergency medical services benefit score: an intra- and inter-rater reliability study in a belgian helicopter medical center

Abstract Introduction The Emergency Medical Service Benefit Score (EBS) was recently developed from the former Helicopter Benefit Score (HBS) to provide a standardized tool for evaluating the benefits of prehospital interventions. While the score has been implemented in daily practice, no study has yet assessed its reliability under real-life conditions. This study aimed to evaluate the intra- and inter-rater reliability of the EBS in a helicopter emergency medical service (HEMS) context, and to explore whether reliability is influenced by rater profession. Methods A single-centre quantitative validation study was conducted at the Centre Médical Héliporté (CMH) in Bra-sur-Lienne, Belgium. Ten physicians and eight nurses participated in the intra- and inter-rater reliability assessments, which were performed using mission records collected prospectively between July 2023 and February 2024. Physicians re-rated 46 previously assessed patients to evaluate intra-rater reliability, while both physicians and nurses rated 21 identical cases for inter-rater comparison. Anonymized intervention reports were randomized, and scores were analyzed using intraclass correlation coefficients (ICC) with 95% confidence intervals. Results The dataset comprised 679 interventions. For intra-rater reliability, 444 paired ratings were analyzed, yielding an ICC of 0.894 (95% CI: 0.837–0.964 Inter-rater reliability was high at the group level, with an overall mean-measure ICC of 0.974 (95% CI: 0.954–0.988), while single-measure ICCs indicated moderate-to-high individual-level agreement. Subgroup analysis showed ICCs of 0.965 (95% CI: 0.937–0.984) among physicians and 0.931 (95% CI: 0.876–0.931) among nurses. Discussion and conclusion This study provides the first evidence of the high reliability of the EBS in real-life prehospital settings, confirming that the EBS can be applied consistently when assessing prehospital missions in a HEMS context. Physicians and nurses both achieved substantial agreement, supporting the tool’s use across professional groups. Further research should extend to other types of prehospital emergency teams, such as ground emergency medical services and Paramedical Interventional Teams, and examine additional aspects of validity, including criterion and content validity, to further consolidate the role of the EBS in evaluating prehospital care.