The Auckland University of Technology authors of the report Benedicte Rouland and Rhema Vaithianathan used three data sets from the Integrated Data Infrastructure for the research.

Vaithianathan said the cumulative prevalence of child maltreatment was a "hidden statistic" and revealed the true workload placed on our system.

"The high levels of notifications are not a concern in themselves, but do highlight the need to make sure our CYF system has the best funding and systems possible to respond effectively to triage these notification.

"This research may prompt a closer look at the quality of "triage" for incoming allegations of maltreatment, and how to best fund and support the social workers who are doing the triage."

The findings showed that cumulative rates of notifications to CPS were much higher in New Zealand than in Western Australia (24 per cent vs 13 per cent). In addition, substantiated maltreatment across childhood was lower than in the United States, but 2.6 times higher than in Western Australia.

The cumulative incidence of out-of-home placements at age 17 years was also lower than in Denmark (5 per cent) and the United States (6 per cent) but twice as high as in England (1.6 per cent).