Abstract
The two leading articles in this issue of Informatics in Primary Care describe the importance of creating the right evidence base if we are to Unleash the Power of e-Health. Policy needs to promote well-thought-out developments that are evi-dence based, have the right theoretical underpinnings and are carefully modelled to see where and how they might fit into the (very human) process of health care delivery and most importantly affect health outcomes. To inform this debate, we need to be clear about what we mean by e-Health and the evidence base, their origins and definitions (Boxes 1 and 2).