Adverse Event Reporting System (AERS) database, which comprises three datasets: adverse event data reported voluntarily through MedWatch (generally by physicians, other health care practitioners, and consumers), mandatory periodically reported data from product manufacturers, and mandatory 7- and 15-day expedited report data from manufacturers following notification of a serious and unexpected adverse event. While this passive surveillance system may be capable of detecting rare serious adverse events, it has several limitations, including profound underreporting, biased reporting, and difficulties in attributing an adverse event to a specific drug. Additionally, when analyzing postmarket epidemiological data collected through passive surveillance, it is difficult to know just how many people have taken a drug (i.e., to determine a denominator), it is difficult to know how many events occurred (i.e., to determine the numerator) because of underreporting, and therefore it is difficult to conclude the rate at which an event would take place (e.g., event x would occur in 1 of every 100,000 persons).

Discussion at the symposium focused on how to enhance the current postmarket safety monitoring system by implementing the recommendations of the IOM report listed above, including upgrading AERS, developing an active surveillance system based on automated health care databases, and building internal epidemiological and informatics capacity at the FDA. Multiple panelists expressed the view that rejuvenating the passive surveillance system and augmenting it with an active system would be a specific feasible next step toward a stronger and more effective drug safety system.

Dr. Dal Pan described several initiatives to enhance the FDA’s current postmarket safety surveillance system. In response to Recommendation 4.1 of the IOM report (improving the generation of new safety signals and hypotheses), the Center for Drug Evaluation and Research (CDER) plans to upgrade to AERS II by adding functionalities that will allow for signal tracking, signal management, and data mining capability. Although the project is currently unfunded in the 2007 budget, the agency is evaluating system requirements and estimates the system could be operational in about 2 years once funded.