Page 67 - JSOM Spring 2026

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Occupation Exposure Measure, Blast Frequency Symptom was present for all recruitment efforts. The ombudsman con-
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Severity, and Salisbury Blast Interview offer greater de- firmed the voluntary nature of participation. All ARSOF per-
tails about blast exposure variables. The BETS includes five sonnel signed an informed consent form before participating
weapons categories specifying sources of blast exposure and in the research activities.
calculates a cumulative exposure score, the generalized blast
exposure value (GBEV). The BETS has quickly become one Study Design & Procedures
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of the most commonly used tools for calculating blast expo- A prospective-cohort study design was implemented for this
sure in military 19,20 and special forces 21,22 research after just study. ARSOF members completed the BETS and a demographic
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four years of the original BETS publication. In Lange et al., intake form one week pre-SFAUC training. The BETS was ad-
the BETS demonstrated strong divergent and convergent va- ministered at two additional time points: the week after SFAUC
lidity among Servicemembers and Veterans. However, there training ended, and eight weeks post-training (Figure 1). The
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is no existing literature on the test-retest reliability of the BETS collected the lifetime history of blast exposure, includ-
BETS. ing, but not exclusive to, the SFAUC training. The demographic
intake form collected age, gender, race, education, military ser-
United States Army Special Operations Forces (ARSOF) mem- vice history, and the Combat Exposure Scale (CES) informa-
bers experience rigorous training and frequent deployments tion. Military service history included total service months,
resulting in multiple occupational blast exposures. Repetitive total months in Special Forces, and total deployed months. The
training and deployment require the use of small and large CES contained seven questions about combat exposure, such as
artillery leading to low- and high-level blast exposures expe- “Did you ever go on combat patrols or have other dangerous
rienced by ARSOF members to a greater degree than conven- duty?” and “How often did you fire rounds at the enemy?”
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tional forces. The high exposure status of ARSOF members Additional data were collected at these time points and during
may put them at greater risk for the development of neuro- training as part of a larger parent study; however, the additional
degenerative pathologies, negative neurobehavioral symp- data are not included in the current analyses.
toms, and other long-term consequences. 3,4,24,25 Specifically,
special operators who have higher GBEV show higher neuro- FIGURE 1 Methods timeline diagram.
inflammation measurements and reductions in cerebellum and ~1 week 6-7 weeks ~1 week ~8 weeks
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brainstem volume. However, these results and others should SFAUC Training
be interpreted with caution as the psychometric properties of Timepoint 1 Timepoint 2 Timepoint 3
BETS and GBEV have yet to be fully examined. Without a full Demographics BETS BETS
BETS
examination of the psychometric properties of BETS, negative
consequences and outcomes (such as misinterpretation of re- Convergent Validity Test-Retest Reliability
Analysis
Analysis
sults, poor tracking of interventions focused on blast exposure,
and biased research findings) are possible and likely. BETS = Blast Exposure Threshold Survey; SFAUC = Special Forces
Advanced Urban Combat.
The purpose of this study was to (1) confirm the convergent The BETS gathered detailed information about a Service-
validity of the GBEV, and (2) determine the GBEV and BETS member’s lifetime exposure to weapons classified into five
item-by-item test-retest reliability among active-duty ARSOF categories: (1) small and medium arms, (2) large arms, often
members (trainers and trainees). Determining the test-retest re- shoulder-fired, that can be carried on a person, (3) artillery,
liability will inform future research and clinical interventions missile weapon systems, or large arms carried by vehicle,
focusing on blast exposure if the BETS is useful in tracking aircraft, or boat, (4) smaller explosives or grenades, and (5)
participants over multiple time points. We hypothesized that larger explosives or targeted explosives at close range. Infor-
(1) GBEV would display strong convergent validity, and (2) mation pertaining to how many years, months per year, days
GBEV and each individual BETS item would have moder- per month, and rounds per day ARSOF members were ex-
ate-good test-retest reliability. We hypothesized GBEV would posed in each category was self-reported. The final question/
display strong convergent validity based on prior convergent item in each weapons category asks how often exposures oc-
validity results (rho-range=0.36–0.76). No previous research curred in two successive days, with responses on a scale of 0
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has examined test-retest reliability in this context; as such, our (none, never) to 100 (all the time). Specifically, the following
hypothesis is based on expert opinion. items are asked about in each weapons category:

1. “Have you ever been exposed to *Weapon Category #* such
Methods
as *Weapon Example*”
Participants 2. “Approximately how many years were you exposed?”
Forty-two active-duty ARSOF participants were enrolled in 3. “On average, how many months per year?”
this study. Participants were included if they were scheduled 4. “On average, how many days per month?”
to participate in an identified Special Forces Advanced Urban 5. “On average, how many rounds per day?” and
Combat (SFAUC) course as a trainee or trainer and between 6. “Over the course of your life, approximately how often did
the ages of 18 and 55 years. Exclusion criteria included foreign exposures occur two days in a row (or more than two days in
nationals or members of other government agencies. a row)?”
All study protocols were reviewed and approved by the Na- The GBEV was calculated using a weighted formula based on
val Medical Center San Diego Institutional Review Board and the Blast Exposure Count (BEC) (Equation 1). Each catego-
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completed in accordance with the Declaration of Helsinki as ry’s BEC was calculated by multiplying the total years, months
revised in 2013. An ombudsman, not affiliated with the study per year, days per month, and rounds per day the ARSOF
or involved in the recruited personnel’s chain of command, member self-reported in each individual category and item.

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