Visit for the latest Coronavirus Disease (COVID-19) updates.

You are here

In This Section:

Adverse Event Reporting System


The Adverse Event Reporting System (AERS) is a computerized information database designed to support the Food and Drug Administration's (FDA) post-marketing safety surveillance program for all approved drug and therapeutic biologic products. The FDA uses AERS to monitor for new adverse events and medication errors that might occur with these marketed products. Reporting of adverse events from the point of care is voluntary. FDA receives some adverse event and medication error reports directly from health care professionals (such as physicians, pharmacists, nurses and others) and consumers (such as patients, family members, lawyers and others). Healthcare professionals and consumers may also report these events to the products’ manufacturers. If a manufacturer receives an adverse event report, it is required to send the report to FDA as specified by regulations.

Food and Drug Administration
Data Years Available: 
Statistics are updated quarterly; data are summarized annually.
Mode of Collection: 
Voluntary reports by consumers and health care professionals of adverse events related to FDA-approved drug and therapeutic biologic products; mandatory reports of adverse events reported to pharmaceutical manufacturers.
Selected Content: 
Patient’s age, gender, weight. Data concerning the event: date of event; type of event (product use error, adverse event, etc.); outcome (death, hospitalization, congenital anomaly, etc.); written description of event. Data concerning the product: product name, manufacturer, lot number and other identifying information, dates of use, diagnosis or reason for use. Data about the person filing report: identifying information, type (consumer, health professional).
Population Covered: 

Reports from consumers, health professionals, and manufacturers can be made by mail, telephone, or on-line. Adverse event reports are entered into the AERS database. Adverse events in AERS are coded to terms in the Medical Dictionary for Regulatory Activities terminology (MedDRA). AERS events are evaluated by clinical reviewers to monitor the safety of products after they are approved by FDA. If a potential safety concern is identified in AERS, further evaluation might include epidemiological studies. Based on an evaluation of the potential safety concern, FDA may take regulatory action(s) to improve product safety and protect the public health, such as updating a product’s labeling information, restricting the use of the drug, communicating new safety information to the public, or, in rare cases, removing a product from the market.

Response Rates and Sample Size: 

AERS contains over 4 million reports of adverse events reported between 1969 and the present.

Interpretation Issues: 

AERS data have limitations. First, there is no certainty that the reported event was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. Further, FDA does not receive all adverse event reports that occur with a product. Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event. Therefore, AERS cannot be used to calculate the incidence of an adverse event in the U.S. population.