Evidence-based policy refers to policy decisions that are informed by objective evidence. Without evidence, policy-makers need to fall back on intuition, ideology, or conventional wisdom.
Originally, the concept has evolved in the medicine, encompassing the toolbox of quantitative experimental methods such as randomized controlled trials or quasi-experimental trials to support medical decisions.
Evidence-based policy has been adopted to drive the policy making process by analysing all available options, impacts, direct and indirect effects, as well as environmental influences. 
E-Policy or Policy 4.0 concepts, which base on a data-driven policy design that takes into account the contemporary rising of big data and data analytics, are one step ahead. Since Big Data brings along the possibility of real-time processing, evaluation results become available at the very moment data arrives. The concepts encompasses a newly shaped policy cycle in which evaluation happen continuously, rather than at the end of the process, but opening permanent possibilities of reiteration, reassessment and consideration.