What FAERS and MAUDE are

FAERS, the FDA Adverse Event Reporting System, holds reports of adverse events and medication errors involving human drugs and therapeutic biologics. Manufacturers must report events they learn of; health professionals and consumers may report voluntarily through MedWatch. openFDA publishes the reports received since 2004, 20,646,523 of them in the current release, with the reporter's free-text narrative removed. FDA now refers to the system as the FDA Adverse Event Monitoring System (AEMS); openFDA still publishes the data under the FAERS name.

MAUDE, the Manufacturer and User Facility Device Experience database, holds medical device reports (MDRs). Manufacturers, importers and user facilities such as hospitals must file; others may. openFDA publishes 26,136,888 reports going back to the early 1990s, again without narrative text.

What a report contains

A FAERS report gives the products involved and whether each is suspected, concomitant or interacting; the reactions, coded with MedDRA preferred terms; whether the reporter considered the event serious and which outcome flags apply; the patient's age and sex; and the kind of reporter. A MAUDE report gives the device's brand, generic name, manufacturer and product code; the event type the filer chose (death, injury, malfunction, other); and coded device and patient problems. Neither includes a medical assessment by FDA of what happened.

Limits, in FDA's words

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

On FAERS, FDA adds that "there is no certainty that the reported event (adverse event or medication error) was actually due to the product," that FDA "does not require that a causal relationship between a product and event be proven," that "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," and that the information "cannot be used to estimate the incidence of these events." Duplicate and incomplete reports are also present.

On MAUDE, FDA states that the system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data," and that "the incidence or prevalence of an event cannot be determined from this reporting system alone due to potential under-reporting of events and lack of information about frequency of device use." FDA's MAUDE page adds: "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices."

What FDA does with the reports

FDA uses these systems, alongside clinical trial data, studies and its Sentinel network, to look for signals that warrant further evaluation. A signal is a starting point for investigation, not a conclusion, and most reports never become one. When FDA reaches a conclusion about a product it acts through labelling changes, safety communications and, rarely, withdrawals, none of which can be inferred from a count of reports.

What this site adds

Counting only. Each page sets a product's reports beside its class and the whole database so that a number has something to be read against, and repeats FDA's limitations. Nothing here is an assessment of any product. Questions about a medicine or device belong with a pharmacist or clinician.