Table 1

Overview of the evidence from both qualitative and quantitative analyses, with exposures categorised according to DSM-5 criteria

DSM-5 criterionExposureNNLimit*Incons†Indirect‡Imprec§Pub bias¶OR (95% CI)**Grad††GRADEPAFReference
Direct exposureNo of army deployments‡‡3333 024No0%NoNoN/A1.15 (1.14 to 1.16)NoModerate7%Figure 2
Combat exposure1128 304Yes89%NoNoYes1.89 (1.46 to 2.45)NoVery low14%Figure 2
Army deployment§§411 023Yes0%NoNoN/A1.79 (1.45 to 2.21)NoLow34%Figure 3
Undergoing a traumatic event131 703 107Min: 0.86 (0.32 to 2.28)
Max: 5.65 (3.27 to 9.74)
Table 2
Cumulative exposure81 749 762Min: 0.97 (0.92 to 1.03)
Max: 6.5 (1.6 to 25.6)
Table 2
Exposure severity32558Min: 1.01 (0.67 to 1.35)
Max: 6.5 (1.6 to 26.0)
Table 2
Witnessing trauma54876Min: 1.01 (0.63 to 1.64)
Max: 9.3 (6.1 to 14.2)
Table 2
Colleague exposed¶¶19800.55 (0.12 to 2.47)Table 2
Indirect exposureConfrontation with death775 902No46%NoNoN/A1.63 (1.41 to 1.90)NoModerate15%Figure 3
414 085Min: 1.03 (1.00 to 1.06)
Max: 4.0 (2.5 to 6.6)
Table 2
Other exposuresStress41 390 641Min: 1.01 (0.98 to 1.04)
Max: 3.52 (2.94 to 4.21)
Table 2
Time since event31 358 468Min: 0.47 (0.32 to 0.70)
Max: 1.89 (0.99 to 3.60)
Table 2
Other369 176Min: 1.08 (0.97 to 1.20)
Max: 5.72 (3.37 to 9.71)
Table 2
  • For exposures for which quantitative analyses could be performed (figures 2 and 3), quality of the evidence for the relationship between work-related exposures and PTSD according to the GRADE framework is shown. Other exposures are described qualitatively (table 2).

  • *Limitation: downgraded if the majority of studies score lower than 60% on the risk of bias scale.

  • †Inconsistency: downgrade if I2 ≥50%.

  • ‡Indirectness: downgrade if indirectness is present.

  • §Imprecision: downgrade if the 95% CI is <1 and >2.

  • ¶Publication bias: downgraded if publication bias is present (based on the funnel plots).

  • **Effect size: upgrade if the lower limit of the 95% CI is >2.0.

  • ††Gradient: upgraded if there is a dose–response gradient available.

  • ‡‡Depicting the effect of being deployed more than once, as compared with being deployed once.

  • §§Depicting the effect of being deployed, as compared with not being deployed.

  • ¶¶For this study on occupational exposures, the DSM-5 criterion ‘relative/friend’ was adapted to ‘colleague or coworker’.

  • DSM-5, Diagnostic and Statistical Manual of Mental Disorders, fifth edition; GRADE, Grades of Recommendations, Assessment, Development and Evaluation; NA, not available; PAF, population attributable fractions; PTSD, post-traumatic stress disorder.