Key influences over actors’ preferences and use of evidence in policy development: insights from the Nigerian IMNCH strategy.

Background Evidence based policy-making has been promoted as a means of ensuring better outcomes but what counts as evidence in policy-making lies within a spectrum of expert knowledge through scientifically generated information. Different actors provide varying degrees of support for and use of different types of evidence in policy development. Since not all forms of evidence share an equal validity or weighting for policy-makers, it is important to understand the key factors that influence their choice of evidence.