About 1 in 10 children in the developed world is abused each year but official statistics indicate less than a tenth of those abused are investigated, a series of international studies showed on Wednesday.

Child protection services are failing to recognise abuse in part because doctors, schools and community health workers underreport it, they wrote in the Lancet medical journal.

Tackling the problem is critical as there is clear evidence that effects from abuse last well into adulthood, making it more likely these children will be violent and engage in risky sexual behaviour as adults, they added.

“Child maltreatment is common, and for many it is a chronic condition, with repeated and ongoing maltreatment merging into adverse outcomes throughout childhood and into adulthood,” Ruth Gilbert of the Institute of Child Health at University College London and Cathy Spatz Widom of City University of New York wrote.

“The burden on the children themselves and on society is substantial.”

The definition of abuse was wide-ranging and included punching, hitting, beating, burning, rape, exposure to pornography as well as neglect and emotional abuse such as making a child feel worthless or unwanted.

Parents account for most types of maltreatment except for sexual abuse, which is usually committed by other family members or an acquaintance, researchers said.

“How frequently this abuse occurs is underestimated by official reports because recording of more than one type of maltreatment is often discouraged by child-protection agencies and official reports often do not capture the chronology of exposure over time,” Gilbert and Widom said.

Better cooperation among doctors, schools and child service agencies could address this, they said. Telephone helplines and confidential counselling could also reach more children at risk.

“Measuring only the risk factors thought to lead to abuse and neglect is not sufficient - programmes must assess actual outcomes of maltreatment and related health outcomes,” Jane Barlow of the University of Warwick in Britain and colleagues wrote.

LONDON (Reuters)