Assessment of clinical and logistical contribution in a Norwegian helicopter emergency medical service using integrated data: a retrospective observational study

BACKGROUND: Physician‑staffed Helicopter Emergency Medical Services (HEMS) provide advanced pre‑hospital care, rapid transfer to hospital, and access to remote areas. These services are costly with limited capacity; therefore, their value depends on meaningful patient benefit. Although clinical and logistical capabilities are essential for selected patient groups, no unified measure of service benefit exists. In 2017 an international expert panel proposed a set of quality indicators (QIs) for Physician‑Staffed Emergency Medical Services (P‑EMS). Since 2021 the Trondheim HEMS has used these QIs to assess clinical and logistical contribution in completed missions. This study aims to describe these contribution assessments and relate them with descriptive data and established severity measures from integrated Emergency Medical Services (EMS) and hospital data. METHODS: Physician‑reported assessments of clinical and logistical contribution from Trondheim HEMS (2022-2024) were linked with data from the Emergency Medical Communication Centre, HEMS records and hospital records. Contribution assessments and mission characteristics were examined using descriptive statistics. Associations and convergence between contribution assessments, severity measures and patient characteristics were explored using multivariable regression models. RESULTS: HEMS contribution was assessed for 2,286 missions. Of these, 1,696 (74%) were judged as beneficial, including 1,173 (51%) with logistical contribution and 897 (39%) with clinical contribution, with an overlap of 374 missions (16%) showing both. Logistical contribution was associated with conditions requiring rapid transfer to definitive treatment, while clinical contribution was associated with potentially critical diagnoses, higher severity scores, higher mortality rates, and greater hospital utilisation. Retrospectively, 590 missions (26%) were classified as having no contribution, more often involving younger patients and potentially critical but uncertain conditions. CONCLUSIONS: Across three years of retrospective physician‑reported assessments, three quarters of HEMS missions were retrospectively considered beneficial, reflecting approximately 50 percent logistical contribution and 40 percent clinical contribution, with a 16 percent overlap. The remaining 26 percent were viewed as not beneficial. Assessments of relative contributions varied between physicians suggests differing interpretations of the criteria, highlighting the need to strengthen a shared understanding of the underlying concepts.