Aspects of standardization as applied to the assessment of drug-event associations

Abstract

Individual case reports about suspected adverse drug reactions are an important source of drug safety data. Their evaluation involves, among other things, the assessment of causality. Usually it is done by expert medical evaluators according to their knowledge and experience. Subjectivity plays a big role as demonstrated by comparison of assessments of the same cases by several evaluators or by the same evaluator at a later date. In recent years, methods of causality assessment based on algorithms were introduced. In these formal approaches, items of information contribute to the assessment in a predetermined and standardized way with a logic that allows operational application. Results obtained with different methods may differ because items of information considered may not be the same and/or strength of evidence attached to them vary from one method to another. The main advantages of standardized assessment are: clear identification of items of information involved, improved communication, reproducibility of results, and the checklist function. Various implications of standardized assessment are discussed and ways to improve their performance outlined.