Getting on the Same Page: Consolidating Terminology to Facilitate Cross-Disciplinary Health-Related Blast Research

Abstract

The consequences of blast exposure (including both high-level and low-level blast) have been a focal point of military interest and research for years. Recent mandates from Congress (e.g., National Defense Authorization Act for Fiscal Year 2018, section 734) have further accelerated these efforts, facilitating collaborations between research teams from a variety of disciplinary backgrounds. Based on findings from a recent scoping review, we argue that the scientific field of blast research is plagued by inconsistencies in both conceptualization of relevant constructs and terminology used to describe them. These issues hamper our ability to interpret study methods and findings, hinder efforts to integrate findings across studies to reach scientific consensus, and increase the likelihood of redundant efforts. We argue that multidisciplinary experts in this field require a universal language and clear, standardized terminology to further advance the important work of examining the effects of blast exposure on human health, performance, and well-being. To this end, we present a summary of descriptive conventions regarding the language scientists currently use when discussing blast-related exposures and outcomes based on findings from a recent scoping review. We then provide prescriptive conventions about how these terms should be used by clearly conceptualizing and explicitly defining relevant constructs. Specifically, we summarize essential concepts relevant to the study of blast, precisely distinguish between high-level blast and low-level blast, and discuss how the terms acute, chronic, exposure, and outcome should be used when referring to the health-related consequences of blast exposure.

Occupational Risk of Low-Level Blast Exposure and TBI-Related Medical Diagnoses: A Population-Based Epidemiological Investigation (2005–2015)

“…Findings regarding fatigue and migraines, two other conditions that have been reported to be associated with LLB [ 5 , 12 , 14 ], were also interesting. They suggest that cumulative exposure to repetitive LLB may be associated with fatigue, although those working in high-risk occupations were less likely to be diagnosed with these conditions overall; these findings parallel the effects demonstrated for sleep disorders and symptoms.…”

“…Because changes in an individual's branch of service (e.g., Marine Corps to Navy), pay grade (e.g., enlisted to officer), or military occupational specialty risk category (e.g., high to low) could also alter how each participant was categorized during analysis, medical and career data for service members was followed until the earliest of the following events occurred: (1) they changed from one branch of service to another; (2) they converted from an enlisted pay grade to a warrant officer or officer pay grade; (3) their occupation changed, resulting in a risk categorization shift (as subsequently described); (4) they were discharged from military service for at least 30 days; or (5) the study end date of 31 December 2015. Data for participants after any of these events occurred were censored and thus not included in subsequent analysis.…”

“…Drawing on findings discussed in the scoping review [ 13 ], it was also hypothesized that occupational risk of LLB would be associated with greater risk of post-concussive syndrome, tinnitus, fatigue, and migraines. Consistent with prior research, it was theorized that the concept of injury ranges on a continuum from non-injured to severely injured, and that exposure to LLB is considered incremental and cumulative in nature and may push people along this continuum thereby increasing their risk of injury [ 5 ]. Therefore, it was predicted that associations between exposure to LLB and clinical diagnoses would be more likely to emerge with greater time in service and should be largely absent among service members at baseline (i.e., with less than 1 year of service).…”

“…More than 50,000 members of the U.S. Armed Forces were wounded while deployed in support of Operations Enduring Freedom, Iraqi Freedom, and New Dawn [ 1 ], and many of their injuries resulted from being in close proximity to detonated explosive devices [ 2 , 3 , 4 ]. When detonated, these explosives subject service members to a shockwave and corresponding increase in ambient pressure (called overpressure) [ 5 ]. Exposure to such explosions is the leading cause of deployment-related traumatic brain injuries (TBIs) [ 4 , 6 ], which are themselves one of the leading causes of deployment-related medical evacuations [ 7 ].…”

“…LLB is similar to HLB in that both are forms of overpressure exposure generated by the detonation of munitions. The term HLB is used to denote overpressure that results from incoming munitions such as improvised explosive devices, whereas LLB denotes overpressure that results from outgoing munitions, such as that generated by firing certain weapons systems (e.g., the Carl Gustav) [ 5 ]. Although there is a strong body of literature identifying the long-term consequences of HLB, research on the adverse outcomes associated with LLB is still in its infancy.…”