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component involved in the initial clot formation after bleed- injuries. 39–45 The DoDTR includes demographic information,
9
ing. A low platelet count (≤150×10 /L) or thrombocytopenia documentation related to accidents and injuries, diagnoses,
has been reported in ATC. 26,27 treatments, and outcomes following injuries. The registry in-
cludes data involving U.S. and non-U.S. military casualties as
Given the paucity of data regarding detection and rate of ATC well as U.S. and non-U.S. civilian casualties from the point
in the Role 1 setting and its significant association with pa- of injury to final disposition. The DoDTR is primarily com-
tient mortality, early detection of coagulopathy is critical to posed of patients admitted to a hospital with an injury diag-
reduce the risk of physiological damage, facilitate appropriate nosis based on the International Classification of Disease 9th
resuscitation and correct the coagulopathy. 7,10,12,13,28,29 Coag- Edition (ICD-9) codes ranging between 800 and 959.9, near-
ulopathy in combat casualties has been described under the drowning/drowning with associated injury (ICD-9 994.1), in-
Role 2/3 setting, which involves a significantly higher num- halational injury (ICD-9 987.9), or trauma occurring within 72
ber of medical personnel and greater availability of diagnostic hours from presentation to a facility with surgical capabilities.
equipment. 30–33 The Role 1 setting, including the battalion aid
station, has been largely disregarded in ATC during the recent Data Analysis
conflicts due to the paucity of resources. 34 We performed all analyses using Microsoft Excel (version 10,
Redmond, WA) and JMP Statistical Discovery from SAS (ver-
Study Goal sion 13, Cary, NC). We described continuous variables using
We performed this retrospective analysis to analyze the inci- means and 95% CIs and compared them using the t test. We
dence of coagulopathy in the forward military environment described ordinal variables or non-normally distributed con-
based on INR and platelet levels. tinuous variables using medians and interquartile ranges, fol-
lowed by the Wilcoxon rank sum test. We described categorical
variables using numbers and percentages and compared them
Methods using the chi-square test or the Fisher exact test if the expected
cell count was <10.
Data Acquisition
We submitted protocol H-19-018x to the U.S. Army Institute
of Surgical Research (USAISR) regulatory office and obtained Case Selection
exemption from institutional review board oversight. We re- Laboratory data are not routinely available within the Role 1
quested and obtained de-identified casualty data captured by phase of care, so we relied on the laboratory studies upon ar-
the Prehospital Trauma Registry (PHTR) prior to May 2019. rival to the emergency treatment area of the Forward Resusci-
We also requested outcome data for PHTR casualties linked tative Surgical Detachment (FRSD; formerly Forward Surgical
to the Department of Defense Trauma Registry (DoDTR). Team), Role 2 and Role 3 facilities after transfer from the Role
Owing to Defense Health Agency requirements regarding de- 1 (typically the battalion aid station).Therefore, only casual-
identified data at the time of data set acquisition, only an age ties within the PHTR, which were linked to the DoDTR, were
46
range and not a specific age was provided for each patient. included. Based on prior data, we defined coagulopathy as
9
7,8,11,12,23–25,47–53
The Joint Trauma System (JTS) Data Analysis Branch linked an INR ≥1.5 or a platelet value of ≤150×10 /L.
casualties from the PHTR to the DoDTR. We executed data We sought to determine the incidence of coagulopathy in ca-
sharing agreement 19-2186 before data transfer. sualties receiving medical care at a Role 1 facility within the
PHTR. The procedures and medications were documented
based exclusively on data within the PHTR (Role 1) to ex-
The USAISR regulatory office reviewed protocol H-19-018
and determined it was exempt from IRB oversight. We ob- clude possible transport elements in the DoDTR prehospital
tained only de-identified data. We executed data sharing agree- data. We categorized all intravenous (IV) fluids, such as 0.9%
ment 19-2186 before data transfer. sodium chloride (normal saline), lactated Ringer’s solution,
and hetastarch, into one binary event. We assumed that ATC
is triggered in the Role 1 setting and is not a de novo finding
Prehospital Trauma Registry (PHTR) within the Role 2 or Role 3 setting. Further, we assumed that
The JTS PHTR is a data collection and analytic tool designed the ATC was associated with trauma and not caused by under-
to provide near-real-time feedback to commanders. As pre- lying chronic medical conditions.
viously described, the primary purpose of this tool is to im-
prove casualty visibility, augment command decision-making Results
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processes, and direct procurement of medical resources.
Additionally, this tool can be used to reduce morbidity and The original data set contained 1,357 casualties, which in-
mortality through performance improvement in the areas of cluded 709 linked to the DoDTR but excluded 648 patients.
primary prevention (tactics, techniques, and procedures), sec- All the 595 patients included in our analysis had at least one
ondary prevention (personal protective equipment), and ter- documented INR or platelet count upon arrival to the Role 2
tiary prevention (casualty response system and tactical combat or 3 facility following transfer from the Role 1 facility. Thus,
casualty care [TCCC]). The U.S. Central Command JTS 114 patients were excluded. Of the observed patient popula-
36
Prehospital Directorate collected TCCC cards and TCCC af- tion, 36% (212) met our definition of coagulopathy. Of those
ter-action reports for information transfer to the PHTR. We labeled as coagulopathic, 31% (185) met the thrombocytope-
have previously described the origins of the PHTR. 37,38 nia criteria, and 11% (68) met the criteria based on elevated
INR, with potential for overlap between criteria (Figure 1).
The DoDTR
The baseline (non-coagulopathic) cohort had a mean INR of
The DoDTR, formerly known as the Joint Theater Trauma 1.10 (95% CI 1.09–1.12) versus 1.38 in the coagulopathic
Registry, is the DoD’s data repository for trauma-related cohort (95% CI 1.33–0.43). The mean platelet count in the

62 | JSOM Volume 24, Edition 2 / Summer 2024