USE OF METAANALYSIS IN DEFINING THERAPY T ARGET POPULATION

The efficacy of a drug is a quantitative concept rather than a qualita tive one. This quantity is expressed by several efficacy indices. None of them meet all the requirements. However, that of absolute benefit is especially suitable for the patients because it tells them the exac t gain they can expect from taking the treatment. The absolute benefit varies according to patients' profiles because it interacts with some components of these profiles. In theory, such interactions can be use d to predict the size of the absolute benefit for each patient, as wel l to describe better than with the current tools the therapy target po pulation. We explain why meta-analysis and effect models are means of improving the prediction of the size of the effect and the definition of the therapy target population.