The primary objective of any reporting system is to generate a "signal": an early indicator or warning of a potential problem. It may be compared to the task of a fire-watcher, who looks for smoke and, if he thinks he spots it, must then determine whether there is indeed a fire and where that fire is located. In pharmacovigilance, it falls to the Medicines Evaluation Board to determine whether there are sufficient arguments to shout "fire!", whereupon it will take the necessary measures.
The reports received by the Lareb Foundation are first assessed by one of its staff doctors or pharmacists. They examine the probability of a causal link, and will use the current literature, previous reports and the description of the drug's pharmacological mechanism to assist them. The results of their assessment are notified to the reporter as well as to the government.
A weekly assessment meeting involves all scientific staff. The reports and their subsequent assessments are discussed to determine whether further action is necessary. Such further action may entail more detailed analysis of the relationship between the reported reaction and the suspect drug. Research within Lareb has revealed a number of factors that can play a significant role in the decision to conduct further analysis. These include the seriousness of the reported reaction, the number of reports related to similar reports on other drugs received by the Foundation, and whether existing literature has devoted attention to the suspected reaction.
During the weekly assessment meeting, all new reports are discussed and further action is scheduled if there seems to be sufficient justification. As a general rule, such action will entail notifying the Medicines Evaluation Board, and in many cases an article will be published.
Computer automation now plays an important role in the internal report assessment process, with all incoming reports undergoing a set sequence of events. The information on the report forms themselves, together with that in any other relevant documentation, is stored in digital form. The weekly assessment meeting also makes use of information obtained through automated quantitative signal generation. The ''Reporting Odds Ratio" is calculated for all reports, providing a statistical indication of the reporting frequency of each of the suspected reactions compared with other reports in the Lareb Foundation's database. The results of the Bayesian Confidence Propagation Neural Network analysis, submitted quarterly by the World Health Organization (WHO) Monitoring Centre in Uppsala are also automatically linked to each report.
At the time of writing (early 2001) the Lareb Foundation's database contained over 30 000 reports. Besides providing a valuable aid to case-by-case analysis, quantitative information can also be used to distil useful information from a large collection of data. Such information will not be provided by a single case analysis. The Lareb Foundation is particularly interested in the possibilities for identifying specific syndromes and in detecting interactions between drugs (van Puijenbroek et al., 1999, 2000). Ongoing research is being conducted into whether certain risk factors for drug reactions can be identified using the information now filed in the database.
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