The top-cited military relevant spine articles

Abstract

Introduction

Historically musculoskeletal injury has substantially affected United States (US) service members. Lumbosacral spine injuries are among the most common sites of injury for service members across all US military branches and usually presents with pain in the lower back and extremities. The aim of this study is to identify and describe the 50 most-cited articles relevant to military medicine on the subject of the spine.

Methods

In April 2020 Web of Science was used to search the key words: spinal cord injury, spine, thoracic spine, lumbar spine, cervical spine, sacrum, sacral, cervical fusion, lumbar fusion, sacral fracture, combat, back pain, neck pain, and military. Articles published from 1900 to 2020 were evaluated for relevance to military spine orthopaedics and ranked based on citation number. The 50 most-cited articles were characterized based on country of origin, journal of publication, affiliated institution, topic, military branch, and conflict.

Results

1900 articles met search criteria. The 50 most-cited articles were cited 24 to 119 times and published between 1993 and 2017. 30 articles (60%) originated in the United States. Aviation, Space, and Environmental Medicine accounted for the most frequent (n = 10) destination journal followed by Spine (n = 8). 37 institutions contributed to the top 50 most-cited articles. The most common article type was clinically focused retrospective analysis 36% (n = 18), clinically focused cohort study 10% (n = 5), and clinically focused cohort questionnaire, cross-sectional analysis, and randomized study 8% each (n = 4). 90% of articles were non-surgical (n = 45). The US Army had the greatest number of associated articles. Operation Iraqi Freedom and Operation Enduring Freedom were the most-cited conflicts.

Conclusion

The 50 most-cited articles relevant to military spine orthopaedics are predominantly clinically focused, arising from the US, and published in Aviation, Space, and Environmental Medicine, Spine, and The Spine Journal.

1. Introduction

As Hirsch suggested in his 2005 proposal of the “h index,” quantifying “impact and relevance of an individual's scientific research output” involves consideration of factors such as an author's number of citations and journals of publication. Facilitated by indexing services such as Web of Science (Clarivate Analytics), citation analysis of the most-cited literature can help to assess the impact of peer reviewed literature for evaluation of research productivity and success while also helping to summarize the state of research in both its successes and shortcomings.1, 2, 3, 4

Although the field of citation analysis within orthopaedic surgery is robust with a variety of topics reviewed and summarized for their most-cited and noteworthy publications, the published literature contains a relative paucity of citation analyses specific to military relevant orthopaedic research. There are analyses specific to orthopaedic research during the Iraq and Afghanistan wars and more generally regarding combat casualty care research.^5,6 Additional published research includes publication rate of Society of Military Orthopaedic Surgeons (SOMOS) annual meeting presentations and analysis of military orthopaedic surgeon research quantity and quality.7, 8, 9 To-date there are no published citation analyses on military relevant orthopaedic research specific to the spine.

Historically musculoskeletal injury has substantially affected United States (US) service members. From 2011 to 2016, the majority of US Army, Air Force, and Marine Corps service members discharged with a “service connected [medical] disability” were assessed for a musculoskeletal condition.¹⁰ Additionally, non-combat musculoskeletal injury accounts for 65% of “medically nondeployable” active component US Army service members.¹¹ Broken down by VA Schedule for Rating Disabilities (VASRD) categories, within the musculoskeletal system “dorsopathies” (versus “limitation of motion” or “arthritis”) were the leading category of disability within US Army and Air Force, accounting for greater than half of musculoskeletal concerns between 2011 and 2016.¹⁰

Lumbosacral spine and general spine injury are among the most common sites of injury for service members across all US military branches, with low back, neck, or upper extremity pain a common occurrence during deployment and noted to be among the most common nonbattle injuries in service members deployed during Iraq and Afghanistan conflicts.¹¹ Risk factors including: age, BMI, pre-enlistment medical examination back diagnosis, and deploying once were among those most associated with a back related disability in service members.¹² Considering both the dearth of citation analyses regarding military orthopaedic spine relevant articles and the frequency of spine specific or spine related orthopaedic injury and pathology in the military orthopaedic patient population, a review of the most-cited literature on this topic may serve two purposes, to 1) facilitate continuing research in this field and 2) to further patient care for the affected patient population.

Our objective was to identify and describe the top 50 most-cited articles relevant to military medicine on the subject of the spine.

2. Materials and methods

In April 2020 utilizing Web of Science, an online citation index, a search using the following terms alone and in various combinations was performed: spinal cord injury, spine, thoracic spine, lumbar spine, cervical spine, sacrum, sacral, cervical fusion, lumbar fusion, sacral fracture, combat, back pain, neck pain, and military. Results were limited to articles published in English between 1900 and 2020.

The results were ranked by number of citations and each individually assessed using its title and abstract for relevance to military patient populations, settings and research, and orthopaedic spine surgery, research and management. Of those articles meeting the search criteria and evaluation for relevance, the top 50 most-cited articles were identified. These articles were characterized in regard to country of origin, journal of publication, affiliated institution, first author, topic, military branch, and conflict.

3. Results

A total of 1900 articles met the search criteria. The top 50 most-cited articles ranged from 119 citations to 24 citations and were published between the years of 1993 and 2017. The most-cited article was Bell et al., ‘s 2009 review and summary of care for head and spine trauma related to Operation Iraqi Freedom that presented to National Naval Medical Center or Walter Reed Army Medical Center for definitive treatment. In this most-cited article the authors identified that most common mechanism of injury and defined the rates of cerebrospinal fluid leak and spinal cord or column injury in those presenting with head trauma. The second most-cited article with 100 citations was Dewing et al., ‘s 2008 investigation of clinical outcomes for young and active military patients undergoing microdiscectomy. The third most-cited article with 61 citations was Schoenfeld et al., ‘s 2012 epidemiologic investigation of incidence of and risk factors for cervical radiculopathy within the US military (See Table 1).

Table 1.

Top 50 most-cited articles.

First Author	Publication Year	Journal	Citations	Title of article
Bell RS	2009	Journal of Trauma, Injury, Infection, and Critical Care	119	Military Traumatic Brain and Spinal Column Injury: A 5-Year Study of the Impact Blast and Other Military Grade Weaponry on the Central Nervous System13
Dewing CB	2008	Spine	100	The outcomes of lumbar microdiscectomy in a young, active population14
Schoenfeld AJ	2012	Journal of Spinal Disorders & Techniques	61	Incidence and Epidemiology of Cervical Radiculopathy in the United States Military 2000 to 20098
Flynn TW	2003	Archives of Physical Medicine and Rehabilitation	60	The audible pop is not necessary for successful spinal high-velocity thrust manipulation in individuals with low back pain15
Larsen K	2002	Journal of Manipulative and Physiological Therapeutics	60	Can custom-made biomechanic shoe orthoses prevent problems in the back and lower extremities? A randomized, controlled intervention trial of 146 military conscripts16
Waris E	2007	Spine	59	Disc degeneration in low back pain - A 17-year follow-up study using magnetic resonance imaging17
Knox J	2011	Spine	51	The Incidence of Low Back Pain in Active Duty United States Military Service Members18
Barkana Y	2000	Injury	48	Prehospital stabilization of the cervical spine for penetrating injuries of the neck - is it necessary?19
Thomae MK	1998	Aviation, Space, and Environmental Medicine	48	Back pain in Australian military helicopter pilots: A preliminary study20
George SZ	2011	BMC Medicine	44	Brief psychosocial education, not core stabilization, reduced incidence of low back pain: results from the Prevention of Low Back Pain in the Military (POLM) cluster randomized trial21
Schoenfeld AJ	2017	Journal of Bone and Joint Surgery-American Volume	43	Risk Factors for Prolonged Opioid Use Following Spine Surgery, and the Association with Surgical Intensity, Among Opioid-Naive Patients22
Ramasamy A	2009	Injury	41	Learning the lessons from conflict: Pre-hospital cervical spine stabilization following ballistic neck trauma23
Feuerstein M	2001	American Journal of Industrial Medicine	41	Working with low back pain: workplace and individual psychosocial determinants of limited duty and lost time24
Cohen SP	2009	Archives of Internal Medicine	40	Back Pain During War An Analysis of Factors Affecting Outcome25
Tumialan LM	2010	Neurosurgical Focus	39	Management of unilateral cervical radiculopathy in the military: the cost effectiveness of posterior cervical foraminotomy compared with anterior cervical discectomy and fusion26
Casez JP	1995	Bone	39	Bone Mass at Lumbar Spine and Tibia in Young Males - Impact of Physical-Fitness, Exercise, and Anthropometric parameters - A Prospective-Study in a Cohort of Military Recruits27
Rosenfeld JV	2015	World Journal of Surgery	37	Current Concepts in Penetrating and Blast Injury to the Central Nervous System28
Larsen K	2002	Spine	37	Can passive prone extensions of the back prevent back problems? A randomized, controlled intervention trial of 314 military conscripts29
Radnitz CL	1998	Journal of Traumatic Stress	36	Posttraumatic stress disorder in veterans with spinal cord injury: Trauma-related risk factors30
Alricsson M	2001	Aviation, Space, and Environmental Medicine	36	Mobility, muscular strength and endurance in the cervical spine in Swedish Air Force pilots31
Smith BM	2008	American Journal of Physical Medicine & Rehabilitation	35	Factors predicting pressure ulcers in veterans with spinal cord injuries32
Klimo P	2010	Neurosurgical Focus	35	Can surgery improve neurological function in penetrating spinal injury? A review of the military and civilian literature and treatment recommendations for military neurosurgeons33
Landau DA	2006	Aviation, Space, and Environmental Medicine	33	Cervical and lumbar MRI findings in aviators as a function of aircraft type34
Cohen SP	2012	The Spine Journal	33	Spine-area pain in military personnel: a review of epidemiology, etiology, diagnosis, and treatment35
Schoenfeld AJ	2012	The Spine Journal	33	Characterization of combat-related spinal injuries sustained by a US Army Brigade Combat Team during Operation Iraqi Freedom36
Schoenfeld AJ	2013	Journal of Trauma and Acute Care Surgery	33	Characterization of spinal injuries sustained by American service members killed in Iraq and Afghanistan: A study of 2089 instances of spine trauma37
Rish BL	1997	Military Medicine	32	Spinal cord injury: A 25-year morbidity and mortality study38
Hendriksen IJM	1999	Aviation, Space, and Environmental Medicine	32	Degenerative changes of the spine of fighter pilots of the Royal Netherlands Air Force (RNLAF)39
Blair JA	2012	The Spine Journal	31	Are spine injuries sustained in battle truly different?40
Drew WED	2000	Aviation, Space, and Environmental Medicine	31	Spinal symptoms in aviators and their relationship to G-exposure and aircraft seating angle41
Schoenfeld AJ	2013	Spine	29	Spinal Injuries in United States Military Personnel Deployed to Iraq and Afghanistan An Epidemiological Investigation Involving 7877 Combat Casualties From 2005 to 200942
Weaver FM	2009	Archives of Physical Medicine and Rehabilitation	28	Provider Perspectives on Soldiers With New Spinal Cord Injuries Returning From Iraq and Afghanistan43
Blair JA	2012	The Spine Journal	27	Military penetrating spine injuries compared with blunt44
Rodriguez-Soto AE	2013	Spine	27	Effect of Load Carriage on Lumbar Spine Kinematics45
Kang DG	2012	The Spine Journal	27	Wartime spine injuries: understanding the improvised explosive device and biophysics of blast trauma46
van den Oord MHAH	2010	Military Medicine	27	Neck Pain in Military Helicopter Pilots: Prevalence and Associated Factors47
Ang BO	2009	Spine	27	Neck/Shoulder Exercise for Neck Pain in Air Force Helicopter Pilots A Randomized Controlled Trial48
George SZ	2012	PLOS One	26	Predictors of Occurrence and Severity of First Time Low Back Pain Episodes: Findings from a Military Inception Cohort49
Kasin JI	2011	Aviation, Space, and Environmental Medicine	26	Whole Body Vibration in Helicopters: Risk Assessment in Relation to Low Back Pain50
O'Connor FG	1993	Spine	26	Low-Back-Pain in Military Basic Trainees – A Pilot-Study51
Sheard SC	1996	Aviation, Space, and Environmental Medicine	26	Back pain in aircrew - An initial survey52
Aydog ST	2004	Aviation, Space, and Environmental Medicine	26	Cervical and lumbar spinal changes diagnosed in four-view radiographs of 732 military pilots53
Young JN	1997	Surgical Neurology	25	Lumbar disc surgery in a fixed compensation population: A model for influence of secondary gain on surgical outcome54
Steinberg EL	2003	Clinical Radiology	25	A comparative roentgenographic analysis of the lumbar spine in male army recruits with and without lower back pain55
Salmon DM	2011	Aviation, Space, and Environmental Medicine	25	Neck Pain in Military Helicopter Aircrew and the Role of Exercise Therapy56
De Loose V	2008	Military Medicine	25	Prevalence and risk factors of neck pain in military office workers57
Petren-Mallmin M	1999	Aviation, Space, and Environmental Medicine	24	MRI cervical spine findings in asymptomatic fighter pilots58
Lehman RA	2012	The Spine Journal	24	Low lumbar burst fractures: a unique fracture mechanism sustained in our current overseas conflicts59
Parsons TW	1993	Military Medicine	24	Spine Injuries in Combat Troops - Panama, 198960
Schoenfeld AJ	2013	Injury	24	Pelvic, spinal and extremity wounds among combat-specific personnel serving in Iraq and Afghanistan (2003–2011): A new paradigm in military musculoskeletal medicine61

The majority of articles originated from the US with 30 articles (68%). Three each (6%) originated from Israel and Sweden and two each (4%) originated from Australia, England, Denmark, and the Netherlands (See Table 2).

Table 2.

Countries of origin.

Countries of origin	No. of articles
United States	30
Israel	3
Sweden	3
Australia	2
England	2
Denmark	2
The Netherlands	2

The most frequent journal of publication was Aviation, Space, and Environmental Medicine (n = 10) followed by Spine (n = 8), The Spine Journal (n = 6), Military Medicine (n = 4), Injury (n = 3), and Archives of Physical Medicine and Rehabilitation and Neurosurgical Focus (n = 2 each) (See Table 3).

Table 3.

Top journals of publication.

Journal	No. of articles
Aviation, Space, and Environmental Medicine	10
Spine	8
The Spine Journal	6
Military Medicine	4
Injury	3
Archives of Physical Medicine and Rehabilitation	2
Neurosurgical Focus	2

The 2010s was the most active decade of publication with 21 articles published during this period, followed by the 2000s with 19 publications and the 1990s with ten publications. 2012 was the most prolific publication year with eight publications, followed by 2009 with five (See Fig. 1).

Fig. 1.

Number of articles published per year.

The most-cited first author was Schoenfeld AJ with six citations followed by Blair JA, George SZ, Cohen SP, and Larsen K with two publications each.

37 institutions contributed to the top 50 most-cited articles. William Beaumont Army Medical Center & Texas Tech University Health Science Center contributed the most with five articles followed by Edward Hines Jr VA Hospital, Johns Hopkins School of Medicine, San Antonio Military Medical Center, University of Florida, Walter Reed National Military Medical Center, Naval Medical Center San Diego, and the Medical Research Unit of Ringkjobing County, Denmark with two articles each (See Fig. 2).

Fig. 2.

Top institutions and their associated number of publications

*William Beaumont Army Medical Center & Texas Tech University Health Science Center

^†Walter Reed National Military Medical Center

^‡The Medical Research Unit of Ringkjobing County.

The most common article subject was war-time injury with 16 articles focusing on this concern, followed by lumbar pain pathology or otherwise related conditions with 13 articles and the cervical equivalent with ten articles. More broadly speaking spine pain or related conditions was the next most common subject with four articles. Injury prevention was the focus of two articles. Basic science evaluation of bone mass, opioid use, pressure ulcers, a posttraumatic stress disorder focus on war-time injury, and a basic science evaluation of spine kinematics were all subjects referenced once (See Table 4).

Table 4.

Top article subjects.

Article subject	No. of articles
War-time injury	16
Lumbar pain/conditions	13
Cervical pain/conditions	10
Spine pain/conditions	4
Injury prevention	2
Bone mass	1
Opioid use	1
Pressure ulcers	1
PTSD and war-time injury	1
Spine kinematics	1

The most common article type was clinically focused retrospective analysis, constituting 18 of the top 50 most-cited articles. The next most common types were clinically focused cohort study accounting for five articles, clinically focused cohort questionnaire, cross-sectional analysis, and randomized study each accounting for four articles, biomechanical studies, clinically focused literature review and prospective cohort analysis each accounting for three articles, and clinically focused subject review accounting for two articles. The majority of articles were non-surgical in their focus accounting for 45 of the top 50 articles, with the remaining five surgically focused (See Fig. 3).

Fig. 3.

Top article types.

While most of the most-cited literature had no specific military branch association, the most frequent explicit association was the US Army with two articles and the US Navy with one. Similarly, while many articles did not specify conflict associations those that did most commonly referred to both Operation Iraqi Freedom (“Iraq”) and Operation Enduring Freedom (“Afghanistan”) or more generally to “the conflict in Iraq and Afghanistan” with a total of nine article associations. Operation Iraqi Freedom had two article associations in which it was the only conflict noted and the conflict in Vietnam and Operation Just Cause (“Panama”) were each noted once (See Table 5).

Table 5.

Top conflicts.

Conflict	No. of articles
Operation Iraqi Freedom (“Iraq") and Operation Enduring Freedom (“Afghanistan")	9
Operation Iraqi Freedom (“Iraq")	2
Operation Just Cause (“Panama")	1
Vietnam	1

4. Discussion

The most-cited article, Bell et al., was a clinically focused retrospective analysis published in 2009 focused on head and spine trauma related to Operation Iraqi Freedom (OIF). The authors reviewed all patients who presented between April 2003 and April 2009 to National Naval Medical Center or Walter Reed Army Medical Center for neurosurgical evaluation of penetrating or closed head trauma. For the 408 patients who met inclusion criteria, the authors evaluated mechanism of injury, Glasgow coma scale (GCS), injury severity score at admission, Glasgow outcome scale (GOS) at time of discharge and 6 month, 1 year, and 2 year intervals, and the secondary outcome measures of CSF leak, spinal cord or column injury, systemic infection, vascular injury, and meningitis. The authors found that the majority of patients were male (401 male) and that explosive blast injury was the most common mechanism of injury (56%) followed by gunshot wound (14.2%). They additionally noted that compared to similar patient populations there was a high rate of associated spinal cord or column injury (9.8%) and CSF leak (8.6%). Of note, the authors were the first to report incidence of spinal cord or column injury specifically in the setting of military head trauma. Spinal fractures and spinal cord injury management was focused acutely on decompression and CSF leak repair followed by resolution of other acute issues and definitive stabilization.

The second most-cited article, Dewing et al., a clinically focused prospective study, evaluated the clinical outcomes over a three year period for 183 patients who had undergone single-level lumbar microdiscectomies with specific attention to Visual Analog Scale (VAS) and Oswestry disability index measures, patient satisfaction, return to military duty, and need for reoperation. Mean age of patients evaluated was 27 years and mean follow-up period was 26 months. The authors found that most patients (84%) returned to unrestricted military duty, mean decrease in VAS leg pain score was 4.7 points and mean Oswestry index fell from 53.6 to 21.2. Furthermore, the majority of patients (85%) were satisfied with their surgery with four individuals overall having additional surgery. They specifically noted that disc herniation at L5-S1 had significantly better outcomes than herniation at the L4-L5 level, as did individuals with sequestered or extruded disc herniations versus those with contained herniations. Contained disc herniations, predominantly axial pain versus radicular pain, preexisting restricted duty, and active smokers were associated with less post-operative patient satisfaction, worse outcome scores, and decreased return to duty rates.

The third most-cited article, Schoenfeld et al., a clinically focused retrospective epidemiologic review published in 2012, queried the Defense Medical Epidemiological Database to evaluate incidence and risk factors for cervical radiculopathy in the US military population between 2000 and 2009. Based on their findings the authors note an incidence of 1.79 per 1000 person-years. The authors found that age was the greater risk factors (with ages 40 years or older found to have the greatest risk). Female sex, White race, senior military positions, and Army or Air Force service branches were also found to be significant risk factors.

The most recently published most-cited article, Schoenfeld et al., also a clinically focused retrospective analysis, was published in 2017 on use of opioid medications one year after surgical spinal procedures and risk factors for continued opioid use. The authors queried the Military Health System Data Repository for TRICARE insurance claims from 2006 to 2014 to identify 9991 patients who had undergone discectomy, decompression, lumbar posterolateral arthrodesis, or lumbar interbody arthrodesis who had no history of opioid use in the six months preceding surgery. The authors found that a small minority of patients (0.1%) continued opioid use at six months post-surgery and that socioeconomic status and pre-existing mental health disorders may play a role in sustained post-surgical opioid use.

The oldest most-cited article, Parsons et al., a clinically focused cohort analysis published in 1993, described the back and neck injuries sustained during Operation Just Cause in Panama. Based on their analysis the authors conclude that spine injuries accounted for the largest source of long-term morbidity by soldiers wounded during Operation Just Cause. They additionally found that severe neurologic injury was common (75%) in those with significant fractures as was major soft tissue injury with high-velocity gunshot wounds (66%).

The most common article subject, type, and topic was on the issue of war-time injury, of the clinically focused retrospective analysis type, and non-surgical in nature suggesting that is where the majority of military related spine orthopaedic research has taken place over the past three decades. This may be due to the relative ease of accessing large population-size data sets that lend themselves to epidemiologic analysis within the military health care system and/or the importance of topics that are spine related, such as risk factors for back pain that affects functional status. That said, within the top three most-cited articles there is a war-time injury trauma related retrospective analysis, a surgically focused outcomes evaluation on the subject of lumbar microdiscectomy, and an epidemiologic evaluation of cervical radiculopathy. This range of article types and topics suggests that despite a bias toward non-surgically focused research there is a diverse array of research foci within military spine orthopaedics.

US based institutions, especially William Beaumont Army Medical Center & Texas Tech University Health Science Center, accounted for the majority of studies among the most-cited articles. It is worth noting that the most-cited author, Schoenfeld AJ was often associated with William Beaumont Army Medical Center. With no other authors associated with this institution his high citation frequency affected how often William Beaumont Army Medical Center was cited.

Aviation, Space, and Environmental Medicine and Spine were the most common destination journals among the most-cited articles. This suggests that the preponderance of the most influential military related spine orthopaedic research is diverse in both content and audience. This is evinced by the diverse distribution of article topics and types.

The most published decade (2010s), as the decade subsequent to a majority of the US involvement in Afghanistan and Iraq, suggests that these conflicts and their resulting effects on soldiers and their musculoskeletal concerns, started to become evident in the most influential military spine literature. This is further supported by the frequency of reference within the most-cited literature to Operation Iraqi Freedom and Operation Enduring Freedom compared to other recent conflicts with US involvement such as Operation Just Cause, Vietnam, and the Gulf War.

Limitations of our study include those intrinsic to the field of citation analysis. First, citation numbers, and therefore the results of a citation analysis, are dynamic and thus the results of this analysis function as representative of the data as of April 2020. That said, considering the most recently published article dates from 2017, the results of this citation analysis are unlikely to change quickly as it takes time for more recently published literature to garner recognition, influence, and citations. Second, the frequency of journal issuance may affect total articles published thereby increasing the likelihood of accumulating a greater number of citations. Third, limiting this analysis to only articles published in English leaves out 55 articles. While not a considerable portion of the literature, those 55 articles may constitute highly cited articles and further analysis is needed to evaluate the consequence of excluding non-English languages.

5. Conclusion

This citation analysis found that the top 50 most-cited military relevant spine orthopaedics articles were non-surgical clinically focused retrospective reviews originating from the US. The most common destination journals for publication were Aviation, Space, and Environmental Medicine and Spine. The greatest number of articles were published during the 2010 decade. Schoenfeld AJ was the most-cited author. Among the associated institutions William Beaumont Army Medical Center & Texas Tech University Health Science Center had the greatest number of citations. The US Army had the greatest number of explicitly stated associated citations and Operation Iraqi Freedom and Operation Enduring Freedom were the most-cited conflicts. Considering these findings, this analysis serves as a summary of the most influential research over the preceding 30 years. As the operational needs of the military, nature of musculoskeletal pathology, and treatment modalities change in coming years it will be important to re-assess these data.

Ethical statement

There were no applicable laws and/or institutional guidelines relevant to this project and no institutional committee approval was needed for its completion. No human subjects were involved and therefore no informed consent was needed.

Funding statement

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Guardian/patient statement

No patients and/or guardians were involved in this project.

CRediT authorship contribution statement

Daniel D. Homeier: Investigation, Data curation, Writing – original draft. Daniel Kang: Conceptualization, Supervision, Writing – review & editing. Robert Molinari: Conceptualization, Supervision, Writing – review & editing. Addisu Mesfin: Conceptualization, Supervision, Writing – review & editing.

Declaration of competing interest

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of Defense or the US Government. Please see separately uploaded ICMJE COI Disclosure forms for Author specific information.