To the Editor The study by Kotwal et al1 demonstrating a lower case fatality rate and (adjusted for Injury Severity Score) a lower killed in action rate after the 2009 mandate to transport wounded US military casualties from the battlefield in Afghanistan is a resounding endorsement of the potential benefit of policy change at the highest level. While transporting critically wounded patients to the hospital quickly makes logical sense, there remain opportunities for more nuanced study. Presumedly owing to the changing nature of the conflict, the proportion of patients wounded by explosion increased from 55.0% before to 67.0% after (P < .001) the intervention.1 The Injury Severity Score is an imperfect instrument to adjust for risk of death at time of injury, even in homogenous populations,2 but is particularly problematic when comparing patients with penetrating blast-fragmentation trauma with patients with other types of wounds. Blast fragmentation typically involves penetration of several body parts with low-energy debris, increasing the anatomically based Injury Severity Score without necessarily affecting risk of death as much as might other types of penetrating trauma. An increasing proportion of blast-fragmentation wounds may account for the decreasing case fatality rate, and Injury Severity Score–adjusted results are a relatively weak argument against this possibility. The observed case fatality rate inflection point after the “golden hour” mandate does suggest an additional effect of quicker prehospital times, but it would be interesting to know whether there was a similar inflection point in the trauma mechanism around this time.
Reade MC. A Military-Specific Injury Scoring System to Aid in Understanding the Golden Hour. JAMA Surg. 2016;151(5):491. doi:10.1001/jamasurg.2015.4915