Measuring Aggregated and Specific Combat Exposures: Associations Between Combat Exposure Measures and Posttraumatic Stress Disorder, Depression, and Alcohol-Related Problems

Research has shown combat exposure to be associated with negative mental health outcomes. Different combat exposure measures are not composed of the same combat experiences, and few combat exposure measures have been directly compared to another measure. Furthermore, research about the unique associations between specific combat experiences and mental health is lacking. We investigated associations between new-onset posttraumatic stress disorder (PTSD), new-onset depression, and alcohol-related problems and two commonly used measures of combat among a sample of 20,719 recently deployed U.S. military personnel. A 13-item measure assessed both direct and indirect combat exposures, and a 5-item measure assessed only indirect exposures. Both combat measures were associated with all outcomes in the same direction (e.g., PTSD, odds ratio [OR] = 2.97 vs. 4.01; depression, OR = 2.03 vs. 2.42; alcohol-related problems, OR = 1.41 vs. 1.62, respectively, for the 5- and 13-item measures). The 13-item measure had a stronger association with some outcomes, particularly PTSD. Each specific item had significant bivariate associations with all outcomes, ORs = 1.43-4.92. After adjusting for other combat exposures, items assessing witnessing abuse, feeling in danger, and knowing someone injured or killed remained associated with all outcomes, ORs = 1.18-2.72. After this adjustment, several items had unexpected protective associations with some mental health outcomes. Results indicated these two combat exposure measures were approximately equally effective for determining risk for negative mental health outcomes in a deployed population, despite having different content. Additional research is needed to replicate and understand how specific combat exposures affect health.

Evaluation of a modified version of the Posttraumatic Growth Inventory-Short Form

Background

Posttraumatic growth is the positive change resulting from traumatic experiences and is typically assessed with retrospective measures like the Posttraumatic Growth Inventory (PTGI). The PTGI was designed to include reference to a specific traumatic event, making it difficult to implement, without change, in prospective survey studies. Thus, a modified Posttraumatic Growth Inventory–Short Form (PTGI-SF) was included in a large prospective study of current and former U.S. military personnel. The current study provides preliminary psychometric data for this modified measure and its ability to assess psychological well-being at a single time point.

Methods

The study population (N = 135,843) was randomly and equally split into exploratory and confirmatory samples that were proportionately balanced on trauma criterion. Exploratory factor analysis and confirmatory factor analysis (CFA) were performed to assess the psychometric validity of the modified measure. The final model was also assessed in a subset of the confirmatory sample with a history of trauma using CFA.

Results

Results supported a single-factor model with two additional correlations between items assessing spirituality and items assessing compassion/appreciation for others. This model also fits among the subset with a history of trauma. The resulting measure was strongly associated with social support and personal mastery.

Conclusions

The modified PTGI-SF in this study captures psychological well-being in cross-sectional assessments, in addition to being able to measure posttraumatic growth with multiple assessments. Results indicate that the modified measure is represented by a single factor, but that items assessing spirituality and compassion/appreciation for others may be used alone to better capture these constructs.