Substantial Equivalence In the 510(k) Approval Process

The entire 510(k) process hinges on the new product being “substantially equivalent” to another approved device. The FDA has two definitions of substantial equivalence. Either:

  1. The new product has the same intended use and the same technological characteristics as the approved device. Or...
  2. The new product has the same intended use as the approved device, but it has different technological characteristics that don’t raise different questions of safety or effectiveness and the new device’s manufacturer has submitted information to the FDA that demonstrates that the device is as safe and effective as the approved device.

These definitions allow the newer product to innovate somewhat on previous designs, but it cannot be so different that the FDA feels that the new device raises new concerns about safety or effectiveness.

The Stages of the 510(k) Approval Process

There is no form or application to make a 510(k) submission. Instead, the details on how to begin the 510(k) approval process are laid out in the Code of Federal Regulations, Title 21, Volume 8, Subpart E. These steps include creating and submitting a 510(k) summary explaining the product’s substantial equivalence to a previously approved product. 

There are four types of business or entity that have to file a 510(k) approval request to the FDA. 

  1. Device manufacturers in the U.S. who want to market a “finished device” according to their own specifications and sell it in the U.S.
  2. Specification developers who make the designs for a finished device but contract the manufacturing out to another group or company.  
  3. Repackers or relabelers who substantially alter the condition or labeling of the device.
  4. Foreign manufacturers, exporters, or U.S. representatives of foreign manufacturers or exporters introducing a device to the U.S. market.

This requirement is designed to catch any potentially risky devices wherever they come through. Once the 510(k) approval process is complete, the FDA will either accept or reject the device as substantially similar. If the device is approved, it will be able to become the basis of another product’s 510(k) approval. 

Potential Flaws With The 510(k) Approval Process

In theory, a system that requires new products to be substantially similar to a previously approved device should be inherently safe. In the majority of cases this is true. However, the system can have some issues with oversight that arise from the sheer volume of 510(k) approval requests.

A 2011 report by The U.S. Institute of Medicine Committee on the Public Health Effectiveness of the FDA 510(k) Clearance Process found that between 1996 and 2009, 48,402 510(k) approval requests were cleared. They also found that 4,115 (8.5%) of those approvals were recalled within six years of their approval. 

Of those recalls, almost 30% were due to device design issues. This means that over 1,000 devices with a design defect worthy of a recall were able to be used as approved devices for other products that were substantially similar under the 510(k) approval process.

Another 28.8% of recalls were due to manufacturing process errors. This may have arisen out of the fact that, in their own words, “FDA does not typically perform 510(k) pre-clearance facility inspections.” They do, however, tell manufacturers they “should be prepared for an FDA quality system (21 CFR 820) inspection at any time after 510(k) clearance.”

This is not to disparage the 510(k) approval process. Even the U.S. Institute of Medicine Committee on the Public Health Effectiveness of the FDA 510(k) Clearance Process found that over 90% of devices cleared through the 510(k) process were not recalled. The important thing to know about the 510(k) process is that it is imperfect and therefore patients should continue to be their own advocates.

Before receiving a device from their doctors, patients should ask how long a product has been on the market. The FDA Manufacturer and User Facility Device Experience database can be used to research potentially dangerous devices and see what side effects have been reported.

Above all, patients should try to work with their health care providers and with the FDA to quickly report and address any side effects from the usage of a device.