For the majority of marketed products, no, or very limited clinical data are required. Of 783 Class I device regulations (each of which typically pertains to more than one device), 720 (92%) are exempt from premarket notification. Similarly, of the 898 Class II device regulations, 75 (8%) are exempt. For the Class I and II products requiring pre-market notification, many applications do not include clinical data. Even when clinical trial information is provided (for Class III devices), these data have some of the same inherent limitations noted in drug trials [i.e. limited size, duration, and select patient population (e.g. restrictions in age, gender, disease complexity)]. In addition, investigators in premarket device clinical trials tend to be those physicians at the "cutting edge'' of product development and who are most familiar with the device's characteristics and application. Thus, limited information may be generated on human factor concerns such as optimal design for ease of use, optimal use environment (e.g. free of electromagnetic interference), labeling that anticipates less sophisticated use or that minimizes maintenance error, or the consequences of re-use on device performance and safety. Once in the marketplace, devices are likely be used by a wide array of physicians and other clinicians of varying skill levels, training, and experience. In addition, less stringent diagnostic and other criteria may be applied reflecting either non-optimal product choice or off-label use, the latter a hallmark of the evolving practice of medicine.
Since no device is free from adverse events and product problems, and since premarket clinical data are limited, postmarket oversight is needed as a "safety net'' to ensure the continued safety and effectiveness of marketed products. Postmarket oversight refers to both postmarket surveillance (and risk assessment) as well as postmarket enforcement. The former refers to the systematic process of adverse event/product problem reporting, monitoring, and evaluation as well as the subsequent, more formal, assessments of identified potential patient risks. The latter refers to investigations of a device firm's compliance with statutory and regulatory requirements. Both processes are integral to product development and evolution. This chapter will focus on the FDA programs constituting postmarket surveillance.
Was this article helpful?