Analysis of the Factors Influencing the Spontaneous Reporting Frequency of Drug Safety Issues Addressed in the FDA’s Drug Safety Communications, Using FAERS Data

IntroductionDrug Safety Communications (DSCs), a major tool for risk communication used by the US Food and Drug Administration (FDA), are also designed to encourage spontaneous reporting. However, the effectiveness of this tool remains unclear.AimThe objectives of this study were to evaluate changes in the frequency of spontaneous reporting before and after the release of DSCs, and to identify the factors influencing spontaneous reporting.MethodsDSCs regarding drug safety issues posted on the FDA website in 2010 were assessed using FDA Adverse Event Reporting System data. The differences in reporting frequencies between the pre-DSC and post-DSC periods were calculated for each safety issue. The effects of several candidate factors on these differences were evaluated using analysis of variance (ANOVA).ResultsIn total, we assessed 26 drug safety issues (46 drug × adverse event combinations). Our results showed that spontaneous reporting frequencies for 12 safety issues tended to increase after the release of DSCs, four tended to decrease, three remained unchanged and seven showed a combination of both increases and decreases. Comparisons among the factors revealed that the reporting frequency tended to increase for issues involving Risk Evaluation and Mitigation Strategies and issues based on observational studies. In contrast, reporting frequencies remained unchanged in issues involving other safety-related regulatory actions (such as label changes) and issues based only on clinical trials.ConclusionThe changes in reporting frequencies between the pre- and post-DSC periods varied among safety issues, but the results suggest that some factors might be related to spontaneous reporting frequency.