Methodological guideline for REA of pharmaceuticals: Criteria for the choice of the most appropriate comparator(s)

The comparator in a relative effectiveness assessment (REA) is a health care intervention or other technology with which a pharmaceutical is compared in order to establish if it has an added therapeutic benefit (including clinical as well as quality of life benefits). Such comparator could be another pharmaceutical, but also a medical device, a procedure or psychological approach, radiotherapy, physiotherapy, surgery or, if appropriate, providing advice, for example advice on diet or smoking, a combination of health care interventions carried out simultaneously or in sequence, or “watchful waiting” (no intervention). This document summarises the available literature, the advice provided by existing national guidelines, and the information from current national practice on the choice of comparator for REA.