Ever wonder how safe and reliable Granny’s new pacemaker is? In most cases it turns out nobody really knows, because the quality of the evidence used by the FDA to approve these devices is poor, according to a study published in JAMA last week.
Sanket Dhruva and colleagues from UCSF drew these conclusions after examining the premarket approval process (PMA) for 78 high-risk cardiovascular devices that received FDA approval between January 2000 and December 2007.
PMA is the most stringent FDA review process for medical devices. The scientists found that 65% of the PMA applications for devices were supported by exactly one study.
And overall, the quality of the studies was abysmal. Some failed to provide details like the number of enrolled participants. Only 27% of them were randomized and even less, 14%, were blinded (blinded, randomized, controlled trials represent state-of-the-art scientific research).
The scientists concluded that in general, the FDA’s premarket approval process for cardiovascular devices lacked statistical firepower required to control for bias and hence draw valid conclusions.
The scientists understood that it is more difficult to subject medical devices to blinded studies, since there is no way to produce a “sugar pill” (that is, placebo) for medical devices.
“But we were surprised that so many devices were approved on the basis of a single study,” Dhruva told the Los Angeles Times.
The FDA started approving medical devices in 1976. Recently, there has been a marked increase in the number of cardiovascular devices implanted in Americans. In 2008, 1.2 million people received stents in the US alone. 350,000 people received pacemakers and 140,000 received implantable cardioverter-defibrillators.