Childhood maltreatment and violent outcomes: A systematic review and meta-analysis of prospective studies

The risk of violence following childhood maltreatment is uncertain. This meta-analytic review identifies prospective studies that have examined this association. We systematically searched three electronic databases (PsycINFO, EMBASE, and MEDLINE) and completed a targeted search on Google Scholar. These were supplemented with scan of reference lists and correspondence with authors. We considered non-English-language and unpublished studies. Studies were included if childhood maltreatment was measured before age 18 years and occurred before violent outcomes. We identified 18 eligible studies with data on 39,271 participants. We conducted meta-analysis to calculate odds ratios using random-effects models. Heterogeneity was explored through subgroup analyses and meta-regression. The overall odds ratio of violent outcomes in childhood maltreatment was 1.8 (95% CI 1.4 – 2.3) with substantial heterogeneity (I^2 = 92%). Meta-regression suggested that risk of violence following childhood maltreatment was higher in samples with higher percentage of females, in higher quality studies, in studies with case-linkage methods compared to studies that followed up participants over time using a prospective cohort design, in studies with general population or matched controls than selected population controls, and with older age when violent outcomes were assessed. In conclusion, the risk of violence perpetration was increased in individuals with childhood maltreatment. Preventive strategies and interventions for childhood maltreatment may have an important role in violence reduction. Methodological issues and recommendations for future research are discussed.