Group psychological programs for intimate partner violence (IPV) survivors would seem particularly useful since they contribute to interrupting women's isolation and have cost-effectiveness advantage. This study aims to analyze whether the effectiveness of group interventions for female survivors of IPV is equivalent to that of the individual format. A cognitive-behavioral trauma-focused intervention program was applied in eight weekly sessions in Madrid (Spain) to IPV female survivors with significant posttraumatic symptoms that were randomly assigned to the individual (n = 25) or group (n = 28) intervention format. Measures of posttraumatic stress (Severity of Posttraumatic Stress Disorder Symptoms Scale), depression (Beck Depression Inventory), anxiety (Beck Anxiety Inventory), self-esteem (Rosenberg's Scale) and social support were analyzed at pre-treatment, post-treatment, and 1-, 3-, 6- and 12-months follow-ups. A total of 28.3% of women dropped out, without significant format differences. Intervention (both formats) had significant improvements with large effect sizes in posttraumatic stress (η2p = 0.56), depression (η2p = 0.45), anxiety (η2p = 0.41) and self-esteem (η2p = 0.26) that maintained in follow-ups (p < 0.001), without significant differences between formats. Both intervention formats had different evolutions for depression and anxiety (p < 0.05), with better effects in the individual format at the first post-test measurements, but the differences tended to disappear over time. Intervention was effective in improving social support, with no significant differences between formats. All in all, both formats showed similar effectiveness. The group format could be an alternative when applying psychological interventions for female IPV survivors, since it would maintain good cost-effectiveness balance, mainly in the long-term.
Keywords: effectiveness; intimate partner violence; posttraumatic stress; psychological treatment; randomized controlled trial.