For a parent, having a child in the hospital is scary enough. Now, a new study paints an even scarier picture: one out of 15 hospitalized children is a victim of a medicine mix-up, accidental overdose or serious drug reaction.

"The rates are high, the potential for error is great and we should as parents be concerned," says Dr. Charles Homer of the National Initiative for Children’s Healthcare Quality.

Actor Dennis Quaid, whose newborn twins were given life-threatening overdoses of heparin, is now pushing for changes requiring hospitals to barcode medicines to match a barcode on a patient's hospital bracelet.

"A lot of times patients get their next-door neighbor's medicine...nurses are overworked and are on 18-hour shifts, there's probably 100 mistakes a day in the hospital," says Quaid

Using a new detection tool, researchers found the rate of children harmed by medicine mistakes was significantly higher than previously thought, over half a million kids a year.

Watchdog groups say prevention strategies are needed and parents need to ask more questions before any drug is given.

"Always ask, what type of medications is the child getting; what are some of the side effects that they may be able to help to look out for," says the Institute for Safe Medication Practices’ Allen Vaida.

The study found that more than half the problems involved powerful painkillers including overdoses and allergic reactions. And that 22 percent of the problems were considered preventable.