Physician-led prehospital management is associated with reduced mortality in severe blunt trauma patients: a retrospective analysis of the Japanese nationwide trauma registry

Abstract Background Although the results of previous studies suggested the effectiveness of physician-led prehospital trauma management, it has been uncertain because of the limited number of high-quality studies. Furthermore, the advantage of physician-led prehospital management might have been overestimated due to the shortened prehospital time by helicopter transportation in some studies. The present study aimed to evaluate the effect of physician-led prehospital management independent of prehospital time. Also, subgroup analysis was performed to explore the subpopulation that especially benefit from physician-led prehospital management. Methods This retrospective cohort study analyzed the data of Japan’s nationwide trauma registry. Severe blunt trauma patients, defined by Injury Severity Score (ISS) ≥16, who were transported directly to a hospital between April 2009 and March 2019 were evaluated. In-hospital mortality was compared between groups dichotomized by the occupation of primary prehospital healthcare provider (i.e., physician or paramedic), using 1:4 propensity score-matched analysis. The propensity score was calculated using potential confounders including patient demographics, mechanism of injury, vital signs at the scene of injury, ISS, and total time from injury to hospital arrival. Subpopulations that especially benefit from physician-led prehospital management were explored by assessing interaction effects between physician-led prehospital management and patient characteristics. Results A total of 30,551 patients (physician-led: 2976, paramedic-led: 27,575) were eligible for analysis, of whom 2690 propensity score-matched pairs (physician-led: 2690, paramedic-led: 10,760) were generated and compared. Physician-led group showed significantly decreased in-hospital mortality than paramedic-led group (in-hospital mortality: 387 [14.4%] and 1718 [16.0%]; odds ratio [95% confidence interval] = 0.88 [0.78–1.00], p = 0.044). Patients with age