Table 1.
Overview of the evidence from both qualitative and quantitative analyses, with exposures categorised according to DSM-5 criteria
| DSM-5 criterion | Exposure | N | N | Limit* | Incons† | Indirect‡ | Imprec§ | Pub bias¶ | OR (95% CI)** | Grad†† | GRADE | PAF | Reference |
| Direct exposure | No of army deployments‡‡ | 3 | 333 024 | No | 0% | No | No | N/A | 1.15 (1.14 to 1.16) | No | Moderate | 7% | Figure 2 |
| Combat exposure | 11 | 28 304 | Yes | 89% | No | No | Yes | 1.89 (1.46 to 2.45) | No | Very low | 14% | Figure 2 | |
| Army deployment§§ | 4 | 11 023 | Yes | 0% | No | No | N/A | 1.79 (1.45 to 2.21) | No | Low | 34% | Figure 3 | |
| Undergoing a traumatic event | 13 | 1 703 107 | – | – | – | – | – | Min: 0.86 (0.32 to 2.28) Max: 5.65 (3.27 to 9.74) |
– | – | Table 2 | ||
| Cumulative exposure | 8 | 1 749 762 | – | – | – | – | – | Min: 0.97 (0.92 to 1.03) Max: 6.5 (1.6 to 25.6) |
– | – | Table 2 | ||
| Exposure severity | 3 | 2558 | – | – | – | – | – | Min: 1.01 (0.67 to 1.35) Max: 6.5 (1.6 to 26.0) |
– | – | Table 2 | ||
| Witnessing trauma | – | 5 | 4876 | – | – | – | – | – | Min: 1.01 (0.63 to 1.64) Max: 9.3 (6.1 to 14.2) |
– | – | Table 2 | |
| Colleague exposed¶¶ | – | 1 | 980 | – | – | – | – | – | 0.55 (0.12 to 2.47) | – | – | Table 2 | |
| Indirect exposure | Confrontation with death | 7 | 75 902 | No | 46% | No | No | N/A | 1.63 (1.41 to 1.90) | No | Moderate | 15% | Figure 3 |
| 4 | 14 085 | – | – | – | – | – | Min: 1.03 (1.00 to 1.06) Max: 4.0 (2.5 to 6.6) |
– | – | Table 2 | |||
| Other exposures | Stress | 4 | 1 390 641 | – | – | – | – | – | Min: 1.01 (0.98 to 1.04) Max: 3.52 (2.94 to 4.21) |
– | – | Table 2 | |
| Time since event | 3 | 1 358 468 | – | – | – | – | – | Min: 0.47 (0.32 to 0.70) Max: 1.89 (0.99 to 3.60) |
– | – | Table 2 | ||
| Other | 3 | 69 176 | – | – | – | – | – | Min: 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.