History of Childhood Abuse in Populations Incarcerated in Canada: A Systematic Review and Meta-Analysis.

BACKGROUND: A history of childhood abuse may affect people's health and criminal justice system involvement. Understanding the prevalence of childhood abuse among individuals in prison is important to inform effective and appropriate correctional services. OBJECTIVES: To review and summarize data on the prevalence of childhood abuse among people experiencing imprisonment in Canada. SEARCH METHODS: We searched for studies in bibliographic indexes, reference lists, and gray literature, and we consulted experts. SELECTION CRITERIA: We included studies published since 1987 that reported data on prevalence of a history of abuse before the age of 18 years among people in Canadian prisons, including any abuse, physical abuse, sexual abuse, emotional abuse, and neglect. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed titles and abstracts for eligibility and reviewed full texts for eligibility. Analyses included summary estimates and meta-regression with random effects. MAIN RESULTS: The search identified 1429 records. We included 34 unique studies in our review and 29 nonoverlapping studies in our meta-analysis. The summary prevalence for any type of childhood abuse was 65.7% (95% confidence interval [CI] = 52.6, 77.7; range = 56.2% to 75.0%) among women; only one study reported the prevalence among men (35.5%). The summary prevalence of sexual abuse was 50.4% (95% CI = 33.5, 67.2; range = 9.9% to 77.3%) among women and 21.9% (95% CI = 15.7, 28.8; range = 8.3% to 55.6%) among men. The prevalence of neglect was 51.5% (95% CI = 43.1, 59.7; range = 45.5% to 65.1%) among women and 42.0% (95% CI = 12.7, 74.6; range = 6.8% to 99.0%) among men. The prevalence of physical abuse was 47.7% (95% CI = 41.3, 54.0; range = 16.3% to 83.0%), and the prevalence of emotional abuse was 51.5% (95% CI = 34.8, 67.9; range = 8.7% to 96.0%); we did not find differences according to gender. Prevalence estimates for all types of abuse showed high and unexplained variability across studies. CONCLUSIONS: Half of people in prisons in Canada experienced abuse in childhood. Public Health Implications. Prisons should incorporate trauma-informed approaches. Research is required to understand the association between a history of childhood abuse and criminal justice system involvement and to prevent childhood abuse and mitigate its adverse effects. Systematic Review Registration. PROSPERO CRD42017056192.