The use of cross-jurisdictional population data to investigate health indicators of child maltreatment.

OBJECTIVES To determine the extent to which children with a hospital admission related to assault or maltreatment or to a notified sexually transmitted infection (STI) have contact with the Western Australian Department for Child Protection (DCP), and to investigate injuries and conditions often associated with child maltreatment and subsequent contact with the DCP. DESIGN, PARTICIPANTS AND SETTING Retrospective cohort study using de-identified, record-linked child protection and hospital morbidity data to identify all children aged 0-17 years in Western Australia between 1 January 1990 and 31 December 2005, and a subcohort of children born in WA between these dates, admissions of these children to public and private hospitals in WA, and their contact with the Western Australian DCP. MAIN OUTCOME MEASURES Annual trends in notifications and substantiations of child maltreatment; proportion of children with assault-related and maltreatment-related hospital admissions resulting in notifications, substantiations, or out-of-home care. RESULTS Most children admitted for maltreatment-related reasons (90%) had contact with the DCP, with 81% of these children being notified, 68% having maltreatment substantiated, and 50% entering out-of-home care. Specific injuries and conditions were associated with children who had greater contact with the DCP, including retinal haemorrhage, rib fractures, multiple injuries, STIs at under 14 years of age, and malnourishment. CONCLUSIONS The health system effectively identifies and notifies real cases of maltreatment, and a high proportion of these are substantiated. Health data play an important role in improving maltreatment surveillance, providing opportunities to make valid comparisons over time and between jurisdictions, as well as to monitor conditions and injuries associated with child maltreatment.