Since Congress passed the Pediatric Medical Device Safety and Improvement Act in 2007, which was designed to stimulate the development of pediatric devices, children have made up only 10 percent of participants in clinical trials, the researchers report.
"Many devices that are approved by the U.S. Food and Drug Administration for use in children have had only very limited study in actual pediatric patients," said lead researcher Dr. Florence Bourgeois, a pediatric emergency medicine specialist at Boston Children's Hospital.
"Patients and physicians should be aware of the limitations in the safety and efficacy data of pediatric devices when making treatment decisions," she said.
Even after a number of regulatory initiatives to increase the number of devices studied and approved for use in children, research on these devices before or after approval remains limited.
"Specifically, we found that in a sample of high-risk devices recently approved for use in children, 84 percent were approved by the FDA without pre-market study in any patients younger than 18 years old," Bourgeois said.
In the clinical trials supporting FDA approval of the devices in children, less than 5 percent of all participants were younger than 18, she added.
Among the 25 devices the researchers examined, most were heart devices, such as implantable cardiac defibrillators or stents. Others included devices for children with severe asthma or undergoing spinal surgery, Bourgeois said.
"Not only were many of these devices tested in limited pediatric populations, but many were also approved on the basis of clinical trials that did not employ a very rigorous trial design," she said.
These findings imply that most devices developed by manufacturers for adults are later approved for children despite the limited evidence of their safety and effectiveness in this group, Bourgeois said.
"Future efforts to increase the availability of medical devices to pediatric patients should insure that devices are adequately studied in pediatric patients both in pre-market and post-marketing studies," she said.
The report was published online April 14 and in the May print issue of Pediatrics.
One regulatory agency representative pointed out a different problem: Few new devices are being developed that are specifically intended for children.
FDA Spokeswoman Susan Laine said, "It's important to note that the study referenced included very few devices indicated for pediatric populations younger than 18 years of age. This underscores the challenges of not only evaluating products for these younger populations, but also getting companies to invest in product development for these age groups."
FDA evaluates all devices for safety and effectiveness based on the indications and data provided by the sponsor, Laine said.
"Because of the small populations involved in pediatrics, many devices may be approved by the Humanitarian Device Exemption pathway, which provides an alternate marketing path if certain criteria are met for rare conditions," she said. "The FDA considers flexible and adaptive clinical trial designs when reviewing devices in any small population. Additionally, the FDA takes into consideration the availability of alternative treatment options."
For the study, the researchers looked at the pre- and post-market testing of devices the FDA considers Class III, or high risk.
Bourgeois' team found that of 22 devices approved for use in kids, 88 percent were only being tested on adults 18 and older. This was possible because the FDA Center for Devices and Radiologic Health considers patients between 18 to 21 to be children, the researchers noted.
Most of the devices approved were not tested in randomized trials -- which are considered the gold standard for clinical trials.
Although the FDA required post-marketing studies of 19 devices once they were in clinical practice, only three required testing on children, the researchers noted.
One expert said the new findings did not come as a surprise.
"This is something those of us in pediatrics have known for a long time," said Dr. Michael Duchowny, a pediatric neurologist and director of academic affairs at Miami Children's Hospital Research Institute.
"It's not just with devices, but with medications as well. About 80 percent of the medications we prescribe have never undergone clinical trials in children," he said. "There are inadequate trials for devices and medications in children."
The effect is a lack of data on devices and drugs used for children, Duchowny said.
Often drugs and devices are used "off label" in children, he said. Duchowny believes the FDA should give companies incentives to test their drugs and devices in children.
For more about medical devices, visit the U.S. Food and Drug Administration.