The Weber Effect and the United States Food and Dr

Authors: Keith B Hoffman Mo Dimbil Colin B Erdman Nicholas P Tatonetti Brian M Overstreet

Publish Date: 2014/03/19

Volume: 37, Issue: 4, Pages: 283-294

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Abstract

The United States Food and Drug Administration’s FDA Adverse Event Reporting System FAERS consists of adverse event AE reports linked to approved drugs The database is widely used to support postmarketing safety surveillance programs Sometimes cited as a limitation to the usefulness of FAERS however is the ‘Weber effect’ which is often summarized by stating that AE reporting peaks at the end of the second year after a regulatory authority approves a drug Weber described this effect in 1984 based upon a single class of medications prescribed in the United Kingdom Since that time the FDA has made a concerted effort to improve both reporting and the database itself Both volume and quality of AE reporting has dramatically improved since Weber’s report with an estimated 800000 yearly reports now being logged into FAERSA total of 334984 AE reports were logged into FAERS for the 62 drugs analyzed here While a few of the drugs demonstrated what could be considered ‘Weber effect’ curves a majority of the drugs showed little evidence for the effect In fact the general AE reporting pattern observed in this study appears to consist simply of increasing case counts over the first three quarters after approval followed by relatively constant counts thereafterOur results suggest that most of the modern adverse event reporting into FAERS does not follow the pattern described by Weber Factors that may have contributed to this finding include large increases in the volume of AE reports since the Weber effect was described as well as a concerted effort by the FDA to increase awareness regarding the utility of postmarketing AE reportingAdverse event AE archives such as the US FDA’s Adverse Event Reporting database FAERS are sometimes assumed to suffer from the ‘Weber effect’ often generalized as ‘after regulatory approval AE reporting peaks by the end of year 2 and then rapidly diminishes with time’

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