Similar to drugs, medical devices in the United States go through a review process by the US Food and Drug Administration (FDA) before they can be marketed for use in patients.
A medical device is used to diagnose, prevent, or treat a medical disease or condition without having any chemical action on any part of the body. There are 3 classes of medical devices:
Class I devices are low-risk devices. Examples include bandages, handheld surgical instruments, and nonelectric wheelchairs.
Class II devices are intermediate-risk devices. Examples include computed tomography (CT) scanners or infusion pumps for intravenous medications.
Class III devices are high-risk devices that are very important to health or sustaining life. Examples include pacemakers and deep-brain stimulators.
Concept and design: Physicians, researchers, and/or engineers come up with an idea for a medical device. There must be a clinical need for the new device in the health care market. The innovator works out the details of the design and manufacturing of the new device. At this stage, many innovators partner with medical device companies, which perform a detailed market analysis in determining which devices to support.
Animal testing: Sometimes the investigational device is tested on animals before it is studied in humans.
Clinical trials: For some devices (generally class III but not class I or II), clinical trials (studies that involve human participants) are conducted to test whether the device is safe and effective for its intended purpose. These trials are sometimes but not always randomized or blinded. Nonapproved high-risk devices generally are studied under an Investigational Device Exemption that requires strict oversight by the FDA’s Center for Devices and Radiological Health as well as a local institutional review board.
Device review: The investigational device either undergoes a review process by the FDA or is deemed exempt from review, depending on the device class and what types of similar devices are already on the market.
Most class I and some class II devices are exempt from review if they are extremely low risk or very similar to existing devices. These exempt devices still must comply with manufacturing and quality control standards.
Class II devices usually undergo a 510(k) review, which focuses on determining whether the new device is “substantially equivalent” to an existing device. 510(k) reviews usually do not require clinical trials to demonstrate substantial equivalence.
Manufacturers of class III devices submit a premarket approval (PMA) application. In reviewing the application, FDA experts decide whether the new device is safe and effective for treating a specific disease or condition. The PMA process must include results from clinical studies, though the specific study design varies depending on the device. For minor changes to existing class III devices, PMA supplements are submitted instead of a full PMA. The use of PMA supplements for cardiac implantable electronic devices is described in an article in the January 22/29, 2014, issue of JAMA.
A less common type of review is a humanitarian device exemption, which is used for devices for patients with very rare conditions.
Device clearance or approval: Devices that fulfill 510(k) review process requirements are considered to be “cleared.” Devices that meet the safety and effectiveness standards in the PMA process are considered to be “approved.” After FDA clearance or approval, the device can then be marketed for sale and use in the United States.
Postmarketing monitoring: The FDA continues to monitor both the side effects and the performance of the device after marketing, primarily by receiving reports of device malfunction. Manufacturers also have postmarket surveillance requirements specific to different device types.
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Source: US Food and Drug Administration
Topic: Health Policy