Postpartum self-inflicted injury, suicide, assault and homicide in relation to immigrant status in Ontario: a retrospective population-based cohort study.

Abstract

Intentional injury, including suicide and assault, is a leading cause of maternal morbidity and mortality. We aimed to determine whether immigrant and nonimmigrant women differ in their 1-year risk of intentional injury after birth. This population-based retrospective cohort study used administrative data from Ontario from 2002 to 2012. Risk of self-inflicted injury (self-harm or suicide), and injury inflicted by others (assault or homicide), were each analyzed within 1 year after delivery of a live-born infant for immigrant and nonimmigrant mothers. Relative risks (RRs) were adjusted for maternal age, parity, income, resource utilization and psychiatric history. The study included 327 279 immigrant and 942 502 nonimmigrant mothers. Risk of self-inflicted injury was similar among immigrants and nonimmigrants (adjusted RR 0.91, 95% confidence interval [CI] 0.78-1.04), with no variation by duration of residence or refugee status. Immigrants were at lower risk than nonimmigrants for injury inflicted by others (adjusted RR 0.57, 95% CI 0.51-0.64); that risk was higher among refugees than among nonrefugee immigrants (adjusted RR 1.79, 95% CI 1.33-2.41), and it was higher among long-term (adjusted RR 2.27, 95% CI 1.76-2.91) and medium-term (adjusted RR 1.58, 95% CI 1.19-2.11) immigrants than among recent immigrants. Variability by country of origin was observed for both injury types. Immigrant mothers have a reported risk for self-inflicted injury after birth similar to that of their Canadian-born counterparts. The extent to which selective underreporting of intentional injury in immigrant women might explain our findings is a key consideration for future research.