A 2005 systematic review included experimental and quasi-experimental studies, and found mixed results for this type of intervention. The average effect measured through official reports of domestic violence in experimental studies showed modest benefits, while the average effect for outcomes measured through victim reports was nil. The results, according to the authors, raise doubts regarding the efficacy of court intervention programs for batterers [1].
An update to this systematic review (developed by two of the same authors of the aforementioned review and published 16 years later) found no data capable of supporting the effectiveness of this type of intervention. Although there is insufficient evidence to conclude that these programs do not work, there is also insufficient evidence to conclude that they do [2].
Based on a sample of 11 studies and a sample size of 4,824 cases, this review analyzed the impact of these programs on repeat intimate partner violence through official reports and victim reports (self-reports). The results found were that, for the treatment group mediating the outcome by official reports, the average effect in experimental studies showed a modest, but statistically non-significant benefit. In turn, the effect measured through victim reports showed equal results for both groups, that is, no effect on the reduction of intimate partner violence [2].
In addition, the authors point out that in recent years a new generation of these programs has emerged, incorporating new elements (such as motivational interviewing). However, they report that there is still insufficient evidence to establish whether these next-generation programs are really able to reduce intimate partner violence, although some promising intermediate results have been observed (program participation and attendance indicators, for example).