Table 1

Summary of location, population, condition of interest and key findings reported in included studies (n = 20)

First Author, YearCountry, Service Branch, Service Location,Population, Number, GroupsCondition and DurationTreatmentKey Findings: visit-specific information, outcomes, adverse events
Randomized Control Trials
DeVocht 2019 [45]

United States Blanchfield Army Community Hospital, KY

SOF

Personnel On-baseLittle or no body pain (avg pain intensity < 4 on 10 scale)CMT: HVLA SMT to cervical, thoracic, lumbopelvic areas, as indicatedMean age 33 ± 5.6 years; male 100%

CMT 4 visits over 2 weeks (n = 60)

vs Wait-list Control (n = 60)

Pain intensity: median (range): 2.0 (0–3.0)
Primary Outcome: Mean change (95% CI) between CMT and wait-list control at 2 weeks not statistically significant:
Wait-list Control: no treatment
Hand simple reaction time: −3.49 (−24.75 to 18.77)
Foot simple reaction time: 0.97 (−18.04 to 19.98)
Choice reaction time: 3.49 (− 14.40 to 21.39)
Fitt’s Law test response time: 0.99 (−0.37 to 2.35)
t-wall response time: − 0.41 (−1.24 to 0.41)
Secondary Outcome:
Mean change (95% CI) pre- and post-reaction response time at visit 2 and final visit in favor of CMT for t-wall response time only.
Visit 2 t-wall response time:-0.90 (−1.71 to −0.09)
Final Visit t-wall response time: − 0.75 (−1.43 to − 0.06)
Adverse events: 0 related to trial procedures 4 related to activities

Goertz, 2013 [29]United StatesOn-base personnelAcute LBP (<4wks)CMT: including HVLA SMT, massage, exercises, McKenzie exercises, mobilization, advice-ADL, postural, ergonomicMean age 26 years; male 86%
Mean duration of complaint 9 days
Radicular signs in 43% of participants
Mean visits SMC 1.4; mean SMC 1 + CMT 7
Mean difference favouring SMC + CMT at 2 weeks:
SMC: include usual care, medications, physical therapy, pain clinic
RMDQ 3.9 (95%CI 1.8, 6.1);
NRS 1.2 (95%CI 0.2, 2.3);
BPFS −7.7 (95%CI −12.9, − 2.6
Mean difference favouring SMC + CMT at 4 weeks:
2 visits weekly over 4 weeks
RMDQ 4.0 (95%CI 1.3, 6.7);
NRS 2.2 (95%CI 1.2, 3.1);
BPFS −10 (95%CI − 14.6, −5.5)
SMC vs SMC + CMT satisfaction with care (mean) at Week 2 = 4.5 and 8.9 and at Week 4, 5.4 and 8.9, respectively
Global Improvement (% moderately better to completely gone): SMC 17%; SMC + CMT 73%
Army
William Beaumont Army Medical CenterSMC + CMT – 2 visits/wk. over 4 wks (n = 45) vs SMC (n = 46)
Participants had higher expectation of helpfulness with SMC + CMT
No follow-up assessments: SMC 35%; SMC + CMT 15%
No serious adverse events. Two mild, expected events reported in SMC + CMT group – 1 unrelated to intervention, 1 sharp pain in LB, referred for medication and resolved in 48 h.

Goertz, 2018 [30]United StatesActive duty service personnelLBP (any duration)UMC withMean age 30.9 (8.7) years; 23.3% female
Army, NavyChiropractic Care: UMC plus up to 12 visits of chiropractic care including SMT, rehabilitative exercise, interferential current; ultrasound, cryotherapy, superficial heat, other manual therapiesMean visits UMC with at least 1 visit to UMC clinician: Walter Reed 2.6 (2.3); San Diego 2.7(2.5); Pensacola 2.3 (2.3)
Walter Reed National Military Medical Centre, Naval Medical Centre San Diego, Naval Hospital PensacolaUMC with chiropractic care (n = 375) 12 visits over 6 wks vs UMC (n = 375)
Mean visits UMC with chiropractic care with at least 1 visit to UMC clinician:
Walter Reed 2.6 (3.1); San Diego 3.5 (3.0); Pensacola 1.6 (1.6)
Mean visits to chiropractor with at least 1 chiropractic visit:
Walter Reed 4.7 (2.5);San Diego 2.3 (1.4); Pensacola 5.4 (2.6)
UMC: include self-management advice, pharmacologic pain management, physical therapy, pain clinic referral
Mean duration (months)
UMC:
< 1144 (38.4)
1–3 40 (10.7)
> 3191 (50.9)
UMC with chiropractic care:
< 1143 (38.1)
1–3 39 (10.4)
> 3193 (51.5)
Primary Outcomes:
Differences observed at all 3 sites
Mean difference favoring UMC with chiropractic care at 6 weeks:
NRS: −1.1 (95% CI −1.4 to −0.7)
RMDQ: −2.2 (95% CI −3.1 to −1.2)
Mean difference favoring UMC
with chiropractic care at 12 weeks:
NRS (average): − 0.9 (95%CI − 1.2 to − 0.5
RMDQ: −2.0 (95% CI −3.0 to − 1.0)
Secondary Outcomes:
Differences observed at all 3 sites
Mean difference favoring UMC with chiropractic care at 6 weeks:
NRS (worst): −1.2 (95% CI −1.6 to −0.8)
Bothersomeness: − 0.4 (95% CI − 0.6 to − 0.2)
Mean difference favoring UMC
with chiropractic care at 12 weeks:
NRS (worst): −1.1 (95% CI −1.6 to −0.7)
Bothersomeness: − 0.4 (95% CI − 0.6 to − 0.2)
Significantly better global
perceived improvement favoring UMC with chiropractic care at 6 weeks:Observed at all 3 sites OR 0.18 (95% CI 0.13 to 0.25)
Significantly greater mean satisfaction with care favoring UMC with chiropractic care at 6 weeks:Observed at all 3 sites2.5 (95% CI 1.6 to 3.0)
Significantly less pain medication
use favoring UMC with chiropractic care at: 6 weeks: OR .73 (95% CI 0.54 to 0.97)
12 weeks: OR 0.76 (95% CI 0.58 to 1.00)

No serious related adverse events.

62 events reported: UMC alone – 19 (3 medication related, 4 epidural injections, 12 muscle/joint stiffness physiotherapy or self-care related. UMC + chiropractic care – 43 (37 muscle/joint stiffness related to chiropractic care and 1 related to physiotherapy care, 1 post epidural injection, 3 not treatment specified, 1 lower limb burning sensation 20 min post manipulation.


Cross-sectional Surveys

Boudreau, 2006 [12]CanadaOn-base Patients, n = 102 Physicians, n = 12MSK complaintsJoint manipulation, soft tissue massage, stretching, exercisePatients – response rate 68%; mean age 37 yr. (SD 8)
Navy

Presenting complaint: 97% axial MSK complaints (52% LBP), 3% extremities; current episode: 41% acute, 56% chronic;Average visits/patient: 5.7 (SD 4.1);

94.2% were satisfied with chiropractic care

Archie McCallum Hospital, CFB Stadacona
Adjunct treatment: interferential current, acupuncture100% agreed: office was easy to get to, attending DC treated them
with respect and concern; 98.6% agree DCs ability to answer questions; 98.5% high satisfaction with clinic hours of operation; 97.1% agreement that DC thought patients were important and was careful to check everything in the examination; 37.6% disagreed or unsure if DC office had appropriate equipment; 33.2% patients reported improvements took longer than expected; and 30.3% expected better results or were unsure if they should have expected better results
Physicians: 100% perceived demand from patients for DC;80.6% satisfied with DC services
Reasons for referral: axial MSK complaints, unresponsive to PT, patient request, PT waiting list too long, history of positive response to DC.

Goertz, 2013 [28]United States, Outside continental United States, Afloat status for NavyActive duty personnel n = 30,664Response rate 51.8%; 5.2% (0.46 SE) reported using chiropractic in preceding 12 months (male 4.9% (0.44 SE; female 6.9% (0.96 SE)
ORs of using chiropractic: 30–39 years 2.26 (95% CI 1.08, 4.74) and 40+ years 3.42 (95% CI 1.36, 8.58) more likely than < 29 years; Black/non-Hispanic 0.35 (95% CI 0.19, 0.66) less likely than White/non-Hispanic; 4 year college education 3.36 (95% CI 1.46, 7.72) more likely than high school education
Army, Navy, Marine Corps, Air Force
Stratified sample of 60 military installations by service and world region, including afloat status for Navy
Adjusted prevalence of chiropractic use (2005): 6.2% (0.62 SE) is less than NHIS (2002): 7.5% (0.19 SE) or NHIS (2007) 8.6% (0.27 SE)

Herman, 2017 [31]United StatesMTF, n = 142Response rate 94% (133/142) 110 MTFs provided CAM services and 60 (55%) of MTF offer chiropractic services; 5 reasons/conditions for using chiropractic services (n = 49): back pain 47 (42.7%), chronic pain 44 (40.0%), headache (excluding TBI related pain) 30 (27.3%), acute pain (post trauma/injury, postop, preop 30 (27.3%), general health/wellness/prevention 12 (10.9%); MHS (2013) number unique patients 55,843; average patient/visits 5.367; average procedures/visit 1.05; MTF estimated number of chiropractic patient encounters 168,00/year
Air Force, Army, National Capital Region Medical Directorate, Navy and Marine Corps
Military treatment facilities

Jacobson, 2009 [32]United StatesActive duty personnel, n = 86,131Response rate Panel 1 71%; Panel 2 25%
Air Force, Army, Marine Corps, Navy, Coast Guard, Reserve/National Guard
10.5% reported using chiropractic care in the preceding 12 months

Netto, 2011 [33]AustraliaRAAF Air Combat Group n = 86Response rate 95% (82/86)
Air Force78% of Royal Australian Air Force Fast Jet Aircrew experienced flight-related neck pain during or after a flight 55% sought treatment for pain; ~ 12% sought chiropractic treatment for flight-related neck pain; ~ 22% reported chiropractic treatment most effective for flight-related neck pain
Off base chiropractic care, which is accessed on a case-by-case basis usually after the failure of on-base services

Petri, 2015 [34]United StatesActive duty personnelResponse rate 2005 100%, 2009 92.1% MTFs: chiropractic services available - 2005 (92%) and 2009 (85%); providing individual chiropractic services - 2005 (92%) and 2009 (79%); number of chiropractors 2005 [15] and 2009 [19]

DoD MTFs surveyed: Army (n = 8), Navy (n = 3), Air Force (n = 2), other (n = 1)

2005 (n = 14) and 2009 (n = 13)


Ryan, 2007 [35]United StatesActive duty and reserve personnel n = 214,338Response rate 36% (77,047/214,338)
Army, navy, Coast Guard, Air Force, Marines.
Chiropractic care use: Active duty 8.0%; Reserve/Guard 14.8%

Smith, 2008 [36]United StatesPopulation: n ~ 550,000Response rate 39% (1446/3683); Results reported on 1310 of 1372 active duty; 8.6% reported using chiropractic care in the preceding 12 months; participants assisted by practitioner with chiropractic services were at increased risk of future hospitalization compared to those self-reporting such use (HR 1.96; 95% CI 1.01, 3.80)
Navy, Marine Corps, Reserve Navy and Marine Corps
In-patient and out-patient
Surveyed random sample: n = 5000 but 3683 were eligible

White, 2011 [37]United StatesIn-patient and out-patient Surveyed random sample active duty personnel, n = 44,28729% reported using at least one practitioner assisted CAM 8.1% reported using chiropractic care in the preceding 12 months
Army, Navy, Air Force, Marine Corps, Coast Guard
Standard Inpatient Data Record; DoD TRI-CARE Management Activity’s Health Care Service Record, Standard Ambulatory Data Record
Case Report

Green, 2006 [38]United States36 yo, maleAcute non-specific LBPInterdisciplinary treatment, with chiropractic care provided over 16 visits in 30 weeks, included HVLA SMT, mobilization, active myofascial release therapy, exercise, ischemic compression.Hospitalization for 24 h, confined to quarters for 72 h and not allowed to return to flying until cleared by flight surgeon.
USMC
Air station Hospital
Consultation and treatment with physiatrist and PT. PT referred to DC at 4 months.
Pain free and return to full function 1 month after last chiropractic visit.

Green, 2008 [39]United States23 yo, maleLBP (persistent synchondrosis of primary sacral ossification center)Treatment: HVLA SMT of sacroiliac joints, stretching, conditioning strengthening and exercises, NSAIDs, advice. Frequency: initial treatment – 2 weeks; 6 weeks after consulting GMO further investigation; recommence treatment – 4wks.Referred to attending chiropractor.
Marine
Naval Medical Center San DiegoInsidious onset after training exercise.
At baseline: Verbal pain scale 7/10 to 9/10 when severe; RMDQ: 14/24; no neuro deficits
Discharged and full RTD.

Green, 2010 [41]United StatesInstructor pilot 38 yo maleUncomplicated mechanical neck painTreatment: 4 visits over 5 wk. & f/u at 6 monthsIntermittent neck pain related to frequent flying F/A-18
Naval Medical Center San Diego Marine Corps
Included: active stretching, HVLA SMT, stretching and strengthening home exercises;Referred for chiro care after no change in symptoms with 2 wks acetaminophen
At baseline: NRS 3/10; NDI 6%; limited end range of motion on right; no neuro deficits
Resolved and full RTD

Green, 2014 [40]United StatesHelicopter mechanic 29 yo, maleMechanical cervico-thoracic pain & myalgiaInterdisciplinary treatmentChronic neck/upper back pain of 7 yrs. post flexion injury with concurrent tinnitus, dizziness and headaches
Naval Medical Center San Diego Marine
Chiropractic care: 8 visits; HVLA SMT, soft tissue mobilizations, advice, home exercises (stretching, strengthening, proprioceptive); Physical therapist care: 5 visits; acupuncture
Baseline: VPS 7/10, painful limitation in motion, no neuro deficits, x-rays-DDD, right elongated styloid process, left calcified stylohyoid ligaments
Treatment discontinued, reported decrease stiffness, VPS 4/10, no adverse events
Returned to work.

Lillie, 2010 [42]United States40 yo, maleAcute episode LBP with radiculopathyInterdisciplinary treatment, with chiropractic care provided over 11 visits in 72 days. Treatment included HVLA and mechanically assisted SMT, interferential therapy, cryotherapy, moist heat, nutritional and psychosocial advice, exercises.Returned to regular exercise routine and able to perform all required Navy Physical Readiness Tests.
Navy Military Treatment Facility Chiropractic Clinic
Subjective complaints resolved and full RTD.

Morgan, 2014 [43]United StatesMilitary officer 25 yo maleC3–5 ALL heterotopic ossification and ankylosisInterdisciplinary treatment including oxycodone HCL/ acetaminophen; chiropractic care: 1/wk. for 13wks, then 1/wk. for 8wks, 1/2wks for 26wks - HVLA SMT thoracic spine, respiratory therapy, aqua therapyTraumatic head injury & right femoral fracture from motor vehicle collision 16 months prior
Walter Reed National Military Medical Center
Baseline: neck and upper back, bilateral hip, knee, wrist, and shoulder pain; VPS 3/10; extremely limited range neck motion; restricted neck & thoracic joint motion; decreased respiratory excursion .5 cm; active deep tendon reflexes; increase CRP, ESR, calcium, alkaline phosphate
Normal chest expansion increased to 3.5 cm, decrease pain

Qualitative Studies

First Author, YearCountry, Service Branch, Service Location,Population, DocumentsKey Findings

Dunn, 2009 [16]United States2-option analysis Legislative reports, policy documents, published worksSystem Related: chiropractic care available at 49 designated MTFs, planned expansion of 11 new locations in 2009–10; TRICARE chiropractic benefit available to active duty service members but not dependents.
DoD
Legislative History: chiropractic integrated in MHS as result of 10 pieces of legislation enacted over 17 yrs. (1993–2009).
Programmatic Growth: initiated as MHS demonstration project (1995); 5-fold increase in number of commands over 14 yr. period.
Leadership Structure: In MHS, leadership for chiropractic program at each command at department head or equivalent, usually two levels below hospital commanding officer. Each branch has Specialty Advisor responsible for issues related to chiropractic activities. No chiropractors functioning at DoD leadership levels. Decentralized structure of MHS and lack of chiropractor in leadership could impact integration.
Employment Status of Providers: Chiropractors in MHS serve in role of contractor or employee of contractors. Navy contracts directly with chiropractors (typically with no major benefits); Army and Air Force contracts with contracting organizations. Contractual relationships limited by contract period and if employees by contractors contract. Chiropractors in MHS may experience less job security and benefit “growth”.
Clinical Work Duties: Chiropractors work within set of parameters (privileges) as established within system/facility, providing comprehensive chiropractic services (e.g. SMT, mobilizations, modalities, rehabilitation), uphold guidelines, and may perform administrative tasks. Typically supervised by non-chiropractor officers. Quality assurance via peer review. Informally, chiropractors interact with other providers in highly transparent environment, attend regular staff meetings, provide in-service training, maintain competencies, and adhere to documentation requirements.
Patient Access: Chiropractic care accessed largely by gatekeeper referral, which may act as limiting factor. Patients must be seen within 30 days.
Patient Demographics: In DoD, chiropractors care for mix of active duty and active duty veteran patients, most likely for musculoskeletal conditions.
Academic Affiliations and Research: First training rotation within DoD in 2001 with New York Chiropractic College at National Naval Medical Center. Two others established but closed. Little research conducted in DoD and no research time provided in contracts.

Mior, 2018 [44]CanadaCanadian Forces Health Services Key informant interviews: MD (n = 7), PT (n = 13), DC (n = 5)Participant perspectives to Barriers, Opportunities and Recommendations to Integrated Chiropractic Services within CFHS: Barriers: 1: Referring to Off-base Chiropractic Services (base-to-base Variation; Gatekeeper Roles; Care Delivery Unit Medical Officer or Lead physiotherapist designated to chiropractor referral role; Decision to refer to chiropractor based on individual clinician preference and experience, rather than a systematic approach).
Canadian Armed Forces
2: Inter-professional Communication (Communication processes affected by site-specific resources and current practices; Current practices reflect clinician perspective and past experience; Written communication (referral, reports) not standardized; No dialogue between health care providers on base and chiropractors).
3. Duplication of Health Care Services (Scope of practice change: physical therapists and chiropractors; Difficulty distinguishing chiropractor as a profession rather than an intervention; Non-uniform personnel, e.g. chiropractor not able to deploy) Opportunities:
1. Musculoskeletal Disorders (Prevalence of MSK conditions, provide care which is clinical and cost effective)
2: Inter-professional Collaborative Care (Collaborative, integrated, patient-centered care; Base-to-base variation dependent upon location, size, resources and primary purpose; Co-location of providers strengthens inter-professional communication and relationships)
3: Evidence-Based Approach (Standardization of clinical care using clinical practice guidelines based upon high quality evidence)
4: The Spectrum of Care (Knowledge of CAF spectrum of care; Utilize chiropractors’ full scope of practice)
Recommendations:
1. First establish personal rather than professional-level relationships
2. Explicate role and responsibilities of chiropractor based on scope of
practice
3. Standardize communication and treatment plans respectful of military
culture
Acronyms:
ADL activities of daily living,
ALL anterior longitudinal ligament,
BPFS back pain functional scale,
CAF Canadian Armed Forces,
CAM complementary and alternative medicine,
CFB Canadian Forces Base,
CFHS Canadian Forces Health Services,
CI confidence interval,
CMT chiropractic manipulative therapy,
CRP C reactive protein,
DC chiropractor,
DDD degenerative disc disease,
DoD Department of Defense,
ESR erythrocyte sedimentation rate,
F/A fighter/attack,
f/u follow-up,
GMO general medical officer,
HR hazards ratio,
HVLA SMT high velocity low amplitude spinal manipulative therapy,
LBP low back pain,
MD medical doctor,
mobs mobilization,
MHS military health system,
MSK musculoskeletal,
MTF military treatment facility,
NDI neck disability index,
NHIS National Health Interview Survey,
NRS numerical pain rating scale,
OR odds ratio,
PT physical therapist,
RAAF Royal Australian Air Force,
RMDQ Roland-Morris Disability Questionnaire,
RTD return to duty,
SD standard deviation,
SE standard error,
SMC standard medical care,
SOF special operation forces,
TBI traumatic brain injury,
VPS verbal pain scale,
UMC usual medical care,
USMC United States Marine Corps,
wks weeks,
yo years old,
yr. years