Developing and evaluating complex interventions: new guidance

This paper, prepared by Peter Craig, Paul Dieppe, Sally Macintyre, Susan Michie, Irwin Nazareth and Mark Petticrew for the Medical Research Council, outlines strategies for the development, implementation and evaluation of complex interventions particularly related to health. It is designed to support researchers to choose the most appropriate methods, funders to understand the limitations of evaluation design and users to evaluate the evidence based on these methodological and practical constraints.


"Complex interventions are widely used in the health service, in public health practice, and in areas of social policy such as education, transport and housing that have important health consequences. Conventionally defined as interventions with several interacting components, they present a number of special problems for evaluators, in addition to the practical and methodological difficulties that any successful evaluation must overcome. Many of the extra problems relate to the difficulty of standardising the design and delivery of the interventions, their sensitivity to features of the local context, the organisational and logistical difficulty of applying experimental methods to service or policy change, and the length and complexity of the causal chains linking intervention with outcome." (Craig et. al.,)


  • Introduction 6
  • Part I Key messages 7
  • Part II Further questions for evaluators 14
  • Part III Case studies 17
  • Conclusion 33


Peter Craig, Paul Dieppe, Sally Macintyre, Susan Michie, Irwin Nazareth and Mark Petticrew (nd), Developing and evaluating complex interventions: new guidance, Medical Research Council (MRC). Retrieved from: