Impact of physician-staffed ground emergency medical services-administered pre-hospital trauma care on in-hospital survival outcomes in Japan

Purpose In Japan, the vehicle used in pre-hospital trauma care systems with physician-staffed ground emergency medical services (GEMS) is referred to as a “doctor car”. Doctor cars are highly mobile physician-staffed GEMS that can provide complex pre-hospital trauma management using various treatment strategies. The number of doctor car operations for patients with severe trauma has increased. Considering facility factors, the association between doctor cars and patient outcomes remains unclear. Therefore, this study aimed to examine the relationship between doctor cars for patients with severe trauma and survival outcomes in Japan. Methods A nationwide retrospective cohort study was conducted to compare the impact of the doctor car group with the non-physician-staffed GEMS group on in-hospital survival in adult patients with severe trauma. The data were analyzed using multivariable logistic regression models with generalized estimating equations. Results This study included 372,365 patients registered in the Japan Trauma Data Bank between April 2009 and March 2019. Of the 49,144 eligible patients, 2361 and 46,783 were classified into the doctor car and non-physician staffed GEMS groups, respectively. The adjusted odds ratio (OR) for survival was significantly higher in the doctor car group than in the non-physician staffed GEMS group (adjusted OR = 1.228 [95% confidence interval 1.065–1.415]). Conclusion Using nationwide data, this novel study suggests that doctor cars improve the in-hospital survival rate of patients with severe trauma in Japan. Therefore, doctor cars could be an option for trauma strategies.