Analysis of Adverse Events Reports Submitted to the Food and Drugs Administration of the United States of America (2007-2012)

Background: Many nations collect data on adverse events (AEs) associated with the use of drugs using what is generally referred to as the Spontaneous Reporting System (SRS) [1,2,3]. Analysis of such data is important in discovering hitherto unknown problems associated with drug use and in understanding the features of the variables related to the problem of adverse drug reactions (ADRs) [4,5,6]. The SRS of the Food and Drugs Administration (FDA) of the United States of America (US), known as the FDA Adverse Event Reporting System (FAERS) [3], is probably the largest system for collecting data on AEs associated with drug use.

Objectives: (i) Find any trends in the variables associated with the problem of adverse events in drug use, (ii) Elucidate some of the issues raised in the literature by way of the evidence provided by the data, (iii) Find the drugs that were most cited as principal suspect in adverse events and (iv) Examine the data for any other notable attributes.

Methods: Quarterly Extracts from the FAERS database covering the period 2007 to 2012, which is publicly available on the website of the Food and Drugs Administration (FDA, US), were analysed. Out of the over fifty (50) variables contained in the extracts, fourteen (14) of them, which were thought to be relevant to the objectives of the study, were examined. Owing to the nature of the data, the tools of frequencies, proportions and averages were used in the analysis of it.

Results: The results of the analysis revealed that for the period 2007 – 2012, the reported cases of adverse events almost tripled (2.7 times), with annual growth rate of 22.1%. Reports on female subjects dominated throughout the period, accounting for a little over two-thirds of the reported cases annually and in the overall number of reports for the period. The proportion of cases that resulted in death appeared to be increasing over time. Non-health professionals are almost as likely as health professionals to report adverse events. Expedited reports (concerning events that are unexpected, from the perspective of the known pharmacology of the suspect drug(s)) accounted for the highest number of cases throughout the period. A large proportion of the cases were reported electronically with an indication of increasing trend over the period under review and in the years following. The age group most involved in adverse events associated with drug use is 45 – 64, followed by the age groups 65 and over, 45 – 59, 18 – 44 and 0 – 17 in descending order of involvement when looked at from the point of view of number of reported cases. However the results of the analysis show that susceptibility to adverse events increases with age; the older one gets the more vulnerable one becomes to adverse events involving drug use. The analysis also revealed that some of the problems that prevent the best use of SRS data, such as missing values for age and sex, mentioned in the literature, existed during the period under consideration [7,8,9].

Conclusion: It is essential to encourage reporting of adverse events, especially accurate and prompt reporting. This is indispensable in dealing with the problem of adverse events in medication use comprehensively; as it not easy to obtain data on the variables involved with the problem through other means and SRS data provide useful insights, especially when keying out factors that contribute to the occurrence of adverse events associated with drug use.