CHICAGO — A study says imprecise measurement of medicine can lead to dosing mistakes.

The results, published online Monday in Pediatrics, underscore recommendations that droppers and syringes that measure in milliliters be used for liquid medicines — not spoons.

The study involved about 300 parents, mostly Hispanics, with children younger than 9 years old. The youngsters were treated for various illnesses at two New York City emergency rooms and sent home with prescriptions for liquid medicines, mostly antibiotics.

Parents were contacted afterward and asked by phone how they had measured the prescribed doses. They also brought their measuring devices to the researchers’ offices to demonstrate doses they’d given.

Parents who used spoonfuls “were 50 percent more likely to give their children incorrect doses than those who measured in more precise milliliter units,” said Dr. Alan Mendelsohn, a co-author and associate professor at New York University’s medical school.

Incorrect doses included giving too much and too little, which can both be dangerous, he said. Underdosing may not adequately treat an illness and can lead to medication-resistant infections, while overdoses may cause illness or side effects that can be life-threatening.