Researchers found that of nearly 17,000 prescriptions made to kids at two urban clinics, 22 percent were never filled. That's similar to what's been seen in studies of adults - among whom anywhere from 16 percent to 24 percent of prescriptions go unfilled.

"There are lots of studies that show that if you're not adherent to your medication, you'll have worse health outcomes," said lead researcher Dr. Rachael Zweigoron, of the Medical University of South Carolina in Charleston.

That goes for adults, but also for kids, according to Zweigoron. It's not clear from the study why more than one-fifth of prescriptions went unfilled. But parents were more likely to pick up certain medications than others.

Antibiotics and other drugs for infections were filled 91 percent of the time, versus 65 percent of prescriptions for vitamins and minerals, for example.

"When your child has an ear infection and is in pain, you have much more of a sense of urgency," Zweigoron said. But if a doctor recommends a vitamin D or iron supplement, she added, parents might not see the immediate need.

That raises the question of whether parents always know why a pediatrician has prescribed a medication or supplement. "Are we, as pediatricians, doing a good enough job of explaining the importance to parents?" Zweigoron said.

The findings, which appear in the journal Pediatrics, are based on 4,833 kids seen over two years at two clinics connected to Lurie Children's Hospital of Chicago.

All of the children were on Medicaid, the government health insurance program for the poor. So it's not clear if the findings would be the same for U.S. kids with private insurance.

But Zweigoron said that unfilled prescriptions are likely a problem, to some degree, among families on private insurance, too. Her team did find that electronic prescriptions were almost 50 percent more likely to be filled than old-fashioned paper ones.

The reason is unknown, but Zweigoron speculated that convenience is a big factor. The finding is also in line with other studies showing that adults are more likely to fill their own prescriptions when they're sent to pharmacies electronically.

Zweigoron said more research is needed to weed out the reasons that parents often leave kids' prescriptions unfilled. For now, she suggested that if parents have questions about a medication, including worries about side effects, they speak up.

"If you're not sure why the doctor's prescribing something, you should feel empowered to ask questions," Zweigoron said.

"And if for some reason they're having trouble getting the medication," she added, "(parents) should bring that up, too."

SOURCE: bit.ly/QvDRFS Pediatrics, online September 24, 2012.

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