"Up-armoring" Military Couples: a Randomized Trial of a Preventive, Online Couple Intervention

This study tested whether access to a self-directed, online couple intervention offered preventively lessened the occurrence of future negative relationship outcomes (i.e., relationship dysfunction, infidelity, intimate partner violence [IPV]) for partnered service members in comparison to the usual resources for relationship assistance in the military. Participants were active duty military in a committed romantic relationship of at least 6-month duration (N = 581; 37.2% married) who had recently completed basic military training and were transitioning into technical training to learn a specific job skill set. Participants were randomly assigned by in-processing week to the intervention or the control condition. The intervention effect was modeled using both intent to treat (ITT) and complier average causal effect (CACE) approaches. None of the hypothesized intervention effects was significant in the ITT models. In contrast, the CACE analyses showed that compliers in the intervention group, defined as participants who created a specific action plan to improve a relationship target, compared with those in the control group who the analyses infer would have created an action plan, scored significantly lower on relationship distress and odds of perpetrating IPV at 6- and 12-month follow-ups. The trial was retrospectively registered with ClinicalTrials.gov on 18 April 2025 (ID: NCT06948877).