Expanding the evidence within evidence-based healthcare: thinking about the context, acceptability and feasibility of interventions

The evidence-based model is crucial to contemporary healthcare. It is dependent on systematic review methodology modelled on an arguably out-dated hierarchy of evidence. There has been a significant increase in medical and health research using qualitative and mixed method designs. The perspective taken in this article is that we need to broaden our evidence base if we are to fully take account of issues of context, acceptability and feasibility in the development and implementation of healthcare interventions. One way of doing this is to use a range of methods which better fit the different aspects of intervention development and implementation. Methods for the systematic review of evidence other than randomized controlled trials are available and there is a readiness to incorporate these other types of evidence into good-practice guidance, but we need a clear methodology and to translate these advances in research into the world of policy.