I01RX002172-01, the Mid-Atlantic (VISN 6) Mental Illness Research, Education and Clinical Center, and the Salisbury VAHCS, Salisbury NC . Any opinions ...
Preliminary Results from a Novel Method for Evaluating Blast Exposure Robert D. Shura1-4, Jared A. Rowland1-3, Sarah L. Martindale1-3, Kayla M. Spengler1, 2, 6, Katherine H. Taber1,2,4,5, 1.Salisbury VA Health Care System; 2. VA Mid-Atlantic Mental Illness Research, Education, and Clinical Center; 3. Wake Forest School of Medicine; 4.Via College of Osteopathic Medicine; 5.Baylor College of Medicine; 6. Nova Southeastern University
The Salisbury Blast Interview
BACKGROUND Blast injuries are relatively unique to service members who deployed to Iraq or Afghanistan. Blast events account for about 78% of WIA cases (Walker et al., 2014). Blast events may or may not result in symptoms consistent with a TBI, and those that do not have been referred to as sub-concussive blast events. Many measurement tools rely on assessing blast-caused TBI, thus miss documenting and evaluating sub-concussive blast events. Additionally, blast events can occur outside of the combat environment, such as during training, and life time history of blast and non-blast TBI complicate accurate assessment. Because of these factors, research is limited on blast exposure and outcomes.
Purpose: The primary aim of this study is to evaluate long term outcomes following blast exposure using a new method to assess blast.
Each blast event is rated individually, with separate sheets for individual events.
RESULTS cont. Group differences were evaluated across those who had and had not been exposed to blast. None of the 10 cognitive measures were significantly different, though PTSD and combat exposure were significantly greater in the Blast Exposed group.
Any blast at any point in history is reviewed. There is no limit to the number assessed.
Table 3. Cognitive and Symptom Results Every effort is made to determine the closest date as possible, using various anchors to help (e.g., when was deployment? How far into deployment were you when it happened?).
Protective factors.
Other injury mechanisms.
This may not be known.
METHOD Participants Participants (n = 178): service members in or Veterans of the US Armed Forces who deployed in support of the wars in Iraq and Afghanistan. Inclusion criteria were: deployment after September 11, 2001; deployment in support of the wars in Iraq or Afghanistan; English speaking; 18 years of age or older; and ability to provide informed consent. Exclusion: TBI with LOC outside of deployment; serious mental illness; active substance use disorder; neurological diagnoses.
Table 1. Sample Demographics
Variable
Blast Exposed1
Blast Unexposed2
Age
41.1 (9.9)
42.8 (9.9)
Education
15.0 (2.5)
15.0 (2.0)
Male
89.8%
78.3%
Minority
39.0%
50.0%
History of TBI
79.1%
70.2%
2.7 (2.0)
2.3 (1.7)
Current PTSD
43.0%
34.3%
SC
88.1%
78.0%
Tours
Note. TBI = traumatic brain injury; PTSD = posttraumatic stress disorder; SC = reeciving VA disability for any condition. 1n = 118; 2n = 60.
Not likely very reliable, but asked. Most relevant if blast was very close (IED under vehicle) or very far (distant mortar explosion).
This is a key part of this interview; each item has its own anchors. Below are pressure anchors. d) Pressure change/gradient: 0 = none 1 = slightly, noticeable but not uncomfortable 2 = noticeable and uncomfortable 3 = moderately, results in minor pain or alteration in function 4 = resulted in minor injury 5 = strongly, resulted in greater than minor injury
Also unique to this interview is a new approach to multiple exposures, relevant when someone is exposed to dozens of blasts in close proximity, such as during a deployment. If a multiple exposure, the first questions rate the “typical,” with worst event rated here.
All ratings were significantly different. Distance was not, likely due to the extreme variability (SD). Subjective ratings were used to predict TBI status. Across all ratings, a pressure rating of 3 or higher produced the best diagnostic accuracy: sensitivity = .54, specificity = .87.
Wind*
1.88 (1.8)
1.06 (1.3)
Debris* Ground Shaking*
2.42 (1.9)
1.46 (1.6)
3.54 (1.4)
2.34 (1.4)
2.50 (1.6)
1.06 (1.2)
1.49 (1.6)
0.41 (0.8)
4.08 (1.3)
3.16 (1.2)
28.97 (61.9)
272.31 (2448.8)
Note. *p < .001.
TMT A
50.3 (11.4)
48.0 (10.2)
1.27
.262
TMT B
50.1 (10.7)
48.4 (11.2)
0.70
.405
COWAT
50.7 (10.2)
48.0 (9.9)
2.34
.129
Animals
52.2 (11.6)
51.0 (11.7)
0.37
.543
Block Design
49.7 (10.0)
47.2 (9.6)
2.03
.157
Matrix Reasoning
50.9 (10.1)
48.0 (10.9)
2.45
.120
Similarities
50.3 (10.3)
48.8 (11.0)
0.64
.424
Digit Span
47.7 (9.2)
48.2 (12.9)
0.07
.785
Coding
48.6 (9.0)
47.5 (9.6)
0.39
.533
Symbol Search
53.0 (10.7)
51.6 (11.0)
0.56
.456
PCL-53
.007
PHQ-93
12.0 (6.3)
9.9 (6.4)
3.35
.069
NSI3
25.7 (16.3)
21.0 (16.4)
2.74
.100
40.8 (17.2)
27.4 (12.6)
< .001
Initial analyses suggest that experienced pressure is most sensitive to a blast leading to a TBI. No TBI
Sound* Distance (ft.)
p
We created a new blast interview to address limitations of other available tools that allows for comprehensive assessment of blast exposures across the lifespan.
TBI
Pressure* Temperature*
F
CONCLUSIONS
Table 2. Sensitivity of Ratings to TBI Variable
Blast Unexposed2
Note. All WAIS subtests are WAIS-IV, ACS demographic T scores; Heaton demographic T scores used for other cognitive tests; selfreport meassures are raw scores. 1n = 92; 2n = 47; 3n = 50 in Blast Unexposed.
RESULTS Results of the rated experiences were evaluated for differences across exposures that met criteria for a TBI and those that did not.
Variable
Blast Exposed1
Blast exposure was associated with PTSD and combat exposure, which was expected given that most blast events occurred during a combat deployment. Blast was also related to higher depressive symptoms and more neurobehavioral symptoms in the long term. Remote blast exposure was not related to poorer outcomes on cognitive measures. Future studies will further validate the blast interview and assess more complex outcomes, such as variables related to multiple blast exposure. Limitations: as with any interview, self-report can be affected by limitations of memory as well as overreporting.
This material is based upon work supported in part by the U.S. Army Medical Research and Material Command and from the U.S. Department of Veterans Affairs [Chronic Effects of Neurotrauma Consortium] under Award No. W81XWH-13-2-0095, the Department of Veterans Affairs Rehabilitation Research and Development Service under Award No. I01RX002172-01, the Mid-Atlantic (VISN 6) Mental Illness Research, Education and Clinical Center, and the Salisbury VAHCS, Salisbury NC . Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the U.S. Government, or the U.S. Department of Veterans Affairs, and no official endorsement should be inferred.
