Materials and Methods: We searched the electronic databases PsycINFO, PubMed, PTSDPubs, the Defense Technical Information Center, and Cochrane Central, as well as bibliographies of existing systematic reviews, to identify English-language studies evaluating the efficacy or comparative effectiveness of stress control interventions published since 1990. Controlled trials and cohort comparisons of interventions with military, law enforcement, and first responders were included. Two independent reviewers screened literature using predetermined eligibility criteria. Researchers individually abstracted study-level information and outcome data and assessed the risk of bias of included studies; data were reviewed for accuracy by the project leader. Changes in PTSD symptom scores from baseline to post-intervention were converted to standardized mean differences for comparison across studies. Risk ratios were calculated for PTSD case rates post-deployment. When several studies that compared an intervention group with a similar control/comparator reported the same outcome category and measure type, we conducted meta-analysis. We conducted meta-regression by adding a categorical variable, representing setting (i.e., in theater) or population (military vs. law enforcement or first responders) to the meta-analysis model to assess whether this variable was associated with the outcome across studies. The quality of the body of evidence (QoE) was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, which considers study limitations (risk of bias), directness, consistency, precision, and publication bias.

Results: Sixteen controlled trials and 13 cohort comparisons reporting PTSD outcomes met inclusion criteria. Eight controlled trials and two cohort studies had high risk of bias, primarily due to poor, differential, or unknown response rate at follow-up. Twenty-four of the 29 studies included military personnel. Interventions included Acceptance-based Skills training, Attention Bias Modification training, stress inoculation with biofeedback, Critical Incident Stress Debriefing, group psychological debriefing, Eye Movement Desensitization and Reprocessing for sub-clinical stress, embedding mental health providers in theater, Third Location Decompression, reintegration programs, and a 3-week post-deployment residential program for psychological resource strengthening.

Conclusion: Although combat and operational stress control (COSC) interventions may play a valuable role in decreasing stress, decreasing absenteeism, and enabling return to duty, a systematic review of 29 studies that included a control/comparison group found little evidence that COSC is effective in preventing PTSD or decreasing PTSD symptom scores in military personnel.”