Background A major dilemma of the military surgeon is the requirement for battlefield trauma expertise without regular exposure to a traumatically injured patient. To solve this problem, the military is partnering with civilian trauma centers to obtain the required trauma exposure. The main objective of this article is to quantify institutional differences and develop a predictive model for estimating the number of 24-hour trauma shifts a surgeon must be on call at civilian centers to experience urgent trauma cases.

Methods Trauma databases from multiple institutions were queried to obtain all urgent trauma cases occurring during a 2-year period. A predictive model was used to estimate the number of urgent surgical cases in multiple specialties surgeons would experience over various numbers of 24-hour shifts and the number of 24-hour shifts required to experience a defined number of cases.

Results Institution 1 had the lowest number of required 24-hour shifts to experience 10 urgent operative cases for general/trauma surgery (10 calls) and orthopedic surgery (6 calls) and the highest number of predicted cases over 12 days, 18.3 (95% CI 11 to 27), with 95% confidence. The expected trauma cases and 24-hour shifts at Institution 1 were statistically significant (p<0.0001). There were seasonal effects at all institutions except for Institution 3.

Discussion There are significant variabilities in trauma center volume and therefore, the expected number of shifts and cases during a specific period of time is significantly different between trauma centers. This predictive model is objective and can therefore be used as an extrapolative tool to help and inform the military regarding placement of personnel in optimal centers for trauma currency rotations.

Level of evidence Economic and value-based evaluations, level II.