CHICAGO (AP) — A hospital group says more needs to be done to prevent medication errors in children.

A safety alert issued Friday by the group comes days after the release of a study finding that drug mix-ups and overdoses harm roughly one out of 15 hospitalized children, a number far higher than earlier estimates.

"This is strongest statement on record to date that children have unique safety needs," said Dr. Matthew Scanlon of Children's Hospital of Wisconsin in Milwaukee, who helped write the warning from the Joint Commission, an independent organization that accredits most of the nation's hospitals.

The alert calls on hospitals to weigh children in kilograms when admitted. Weight in kilograms is standardly used to calculate proper doses for children, but some hospitals still weigh them in pounds, increasing the risk of a doubled-dose, Scanlon said.

Hospitals also should clearly mark products that have been repackaged from adult formulations for use with children, the alert says.