It took 29 days or longer to see the children involved in more than half of the child protection cases that started in Queensland last year.
Out of the 22,486 child protection investigations commenced in 2016-17, 50.5 per cent began after 29 days or more, according to data released by the Productivity Commission, for the Steering Committee for the Review of Government Service Provision.
About one in four investigations began in seven days or fewer, one in 10 took eight to 14 days, 7.9 per cent took 15 to 21 days and 6.2 per cent took 22 to 28 days.
In Queensland, child safety officers must sight a child before any investigation can be recorded as having "commenced".
The release notes child safety officers begin working on cases before sighting a child by reviewing the child protection history and getting in contact with police, schools and hospitals.
In 2016-17, there were 19,219 child safety investigations finalised in Queensland, of which 32.4 per cent were substantiated.
That means abuse or neglect, or risk of abuse or neglect, was confirmed.
Out of the 10,958 Queensland children in out-of-home care during the year, 1.5 per cent were the subject of substantiated sexual, physical or emotional abuse or neglect.
Spending on out-of-home care services was more than half a billion dollars in 2016-17 or $162.92 per placement night.
Children on guardianship or custody orders performed poorer on reading and numeracy NAPLAN tests.
While 93.8 per cent of all Queensland students met the reading benchmark, that number dropped to 75.5 per cent for children on orders.
In numeracy, 95.5 per cent of all Queensland students met the benchmark compared with 76.7 per cent of children on orders.
More than two in five children in at least one out-of-home care placement in Queensland during 2016-17 were Aboriginal or Torres Strait Islander.
Nationally, 233,795 children were the subject of notifications, the equivalent of 42.6 notifications per 1000 children in the population.
There were 49,315 children who were the subject of a substantiation, the equivalent of 9 substantiations per 1000 children in the population.
As at June 30, 2017, the proportion of children placed with relatives or kin was 49.5 per cent across Australia.
Total recurrent spending on child protection, out-of-home care, family support services and intensive family support services was $5.2 billion nationally in 2016-17 - a real increase of 8.5 per cent from 2015-16.
