APPLICATION OF THE CAPTURE RECAPTURE METH OD TO SPONTANEOUS REPORTINGIN DRUG SURVEILLANCE/

The incidence of adverse effects of a drug can be evaluated from the r elationship between adverse effects reported to the drug company and t o French drug surveillance centres and the number of patients exposed to the drug. Many adverse effects are never reported and this under-re porting is variable. The capture/recapture method can be used in drug surveillance to evaluate the importance of underreporting for an adver se effect of a drug. This method, based upon the intersection of two d ifferent data sources with the aim of identifying the number of common cases, can estimate the number of unreported cases if at least two in dependant data sources are available. Scrupulous identification of eac h case and of common cases and study of the independence of the two sy stems are essential for this method. The application of the capture/re capture method to spontaneous reporting permits the estimation of the total number of cases and the completeness of registration of the two data sources (the drug company and the French drug surveillance centre s). This application of the capture/recapture method needs to be valid ated by comparing the results to the results of prospective studies wh enever possible.