Background: Chronic pain is of major concern to global health and one of the top reasons for a patient to seek physician care. The prevalence of chronic pain in the civilian population has been well documented, as has chronic pain with certain injuries commonly seen in veterans; however little is known about the burden of chronic pain in the general population of veterans.
Objectives: The objective of this review is to summarize the evidence on the prevalence of chronic pain and related risk factors in military veterans.
Inclusion criteria: Types of participants
International studies that included military veterans.
Focus of the review
Studies that evaluated the prevalence of and/or related risk factors associated with chronic pain in the general military veteran population.
Types of studies
Analytical and descriptive epidemiological studies including prospective and retrospective cohort studies, and cross sectional studies.
Search strategy: The search strategy targeted both published and unpublished studies. An initial limited search of MEDLINE and CINAHL was undertaken, followed by an analysis of the text words contained in the title and abstract, and of the index terms used to describe the article. A second search in MEDLINE, CINAHL, Embase, PsycINFO and Web of Science included all identified keywords and index terms. Reference lists were hand searched. Inclusion criteria were English language studies published between 1996 and 2013. The search for unpublished studies included: Dissertations and theses, MedNar, Centers for Disease Control and Prevention (CDC). All identified studies were assessed for relevance based on information provided in the title, abstract and subject terms. Full papers were retrieved for studies that satisfied the inclusion criteria, or if there was uncertainty regarding relevance. Studies identified from reference list searches of included studies were assessed for relevance based on the title.
Data collection: Two independent reviewers extracted data from the selected papers using the standardized data extraction tool from Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI).
Data synthesis: Meta-analysis was not possible due to methodological and statistical heterogeneity of the studies. Hence study findings are presented in narrative form.
Results: A total of 4829 citations were located by the search strategy. Of this set, 1218 were duplicates, 3536 were off-topic and 73 did not meet inclusion criteria. Twelve studies were included in this systematic review. The prevalence of pain ranged from 25% to 72%. The prevalence of moderate to severe chronic pain of at least three months duration was 27.4%. Factors associated with chronic pain included sex, being married, lower levels of education, smoking, emotional distress, rank, type of service and being younger.
Conclusions: There is a significant burden of chronic pain in veterans, and it appears to be higher than in civilian populations. However, the current evidence is limited by the paucity of available studies and the variability in study design and pain measurement.
Implications for research: The findings of this review may be useful for clinician and policy decisions to improve the care of veterans and to target veterans with a high burden of chronic pain.