PRM79 - WEBER EFFECT: AN EXTENDED ANALYSIS FOR TEN YEARS OF REPORTING TRENDS IN FDA ADVERSE EVENT REPORTING SYSTEM (FAERS)

Abstract

The Weber effect, a peak in adverse event (AE) reporting of a drug at the end of second year and continuous decline thereafter, has been considered an important bias for a long time. The aim of this study was to analyze the temporal reporting patterns of fourteen drugs (approved in 2006) for ten years in FAERS database. A retrospective analysis was executed on the fourteen drugs approved in 2006. The drugs were selected according to the following conditions. Drugs should be approved in 2006 so that the Adverse Event (AE) reports will be available for at least ten years and the drug should not have acclaimed any major safety alerts. Reports of all drugs were normalized for ease of analysis in such a way that the highest count in the reports of any of the 40 quadrants of the drug in question was considered as 100 and remaining count of reports of that particular drug was normalized accordingly. The reporting pattern were analyzed by quarterly and yearly basis. The data set for analysis was retrieved from FAERS database between 2006 and 2016. The analysis was performed by using 19,539 primary suspected reports associated with the fourteen drugs approved in 2006. Four different types of reporting patterns were observed on analysis according to quarterly basis, namely, transitory decline, plateau prior to the rise in AE reports resumes, Weber effect, M-type pattern. Significant Weber pattern was observed when the reports were analyzed yearly basis. The present analysis showed that FAERS reporting is pertinent to Weber effect. It is advisable to address Weber effect in all studies which utilize FAERS database and quantification of such effects are required as it may affect the results drawn from the database.