In the US, there is no consensus on the role of economics, such as determining value for money, in the conduct of CER itself. Indeed, there are legislative constraints on the use of CER and cost-effectiveness analysis in making coverage decisions for the Medicare program and other health programs administered by the Department of Health and Human Services ( Neumann 2012 ; Pearson 2010 ). Even so, the findings of CER and other evidence that may involve health economic analyses, such as cost-effectiveness analysis, is available for use by various analysts and decision makers. While the term “CER” is most often used in the US, other countries and regions use related, though not necessarily synonymous terms. For example, in Europe, there has been growing interest in “relative efficacy” and “relative effectiveness” trials for new drugs. This interest derives in part from differing evidence requirements that sometimes arise between regulatory agencies, particularly the European Medicines Agency (EMA) , and payment authorities. Approaches under consideration involve identifying circumstances in which pre-licensing (pre-marketing) efficacy trials should use active comparators, and ways to close gaps between efficacy and effectiveness, including whether to conduct pre-licensing or post-licensing practical clinical trials (with more heterogeneous patient populations in real-world settings), or to better understand how such extrinsic factors as physician prescribing or patient adherence affect variability in drug response ( Eichler 2009 ; Glaeske 2012 ). These proposals may affect the relative roles and relationships of regulators, payers, and HTA agencies.