Study on the problems in the adverse event report of clinical trials

The decision making process by patients of whether or not to participate in clinical trials occurs in relation to the balance of profits obtained from clinical trials and the disadvantage (especially, health damage) experienced in clinical trials, and the information about a critical adverse event is an important factor in the decision making process. Among all report cases (1,907 cases) provided to our hospital, 1,014 cases (53%) were known adverse reactions and 844 cases (44%) were newly detected, The invesigators (physicians) judged the causal relationship between the investigational drug and adverse events observed, as follows; "definite" 228 cases (12%), "probable" 555 cases (29%), "unlikely" 118 cases (6%), and "unknown" 907 cases (48%). Because about one half of all events make up "unknown" events, the burden and responsibility of the medical institutions which undertake clinical trials to evaluate the clinical importance of reported events are very large. Many of the events are observed in the drugs which are available commercially in foreign countries at present, and the burden of information management is great for the institutions. Another new problem is the difference in the interpretation of information given in English, such as CIOMS report style and MedWatch report style, which may cause some confusion. It is possible to enhance the accuracy of judging a causal relationship by standardization of the information item and establishing the collection system. The transmission of information using electronic media can increase the efficiency of data management in both the medical institutions and the clinical trials subjects.