Realist randomised controlled trials: Evaluating complex public health interventions

Chris Bonell, Adam Fletcher, Matthew Morton, Theo Lorenc and Laurence Moore Social Science & Medicine, 2012; in press, online from 6 Sept 2012 Download publication

Randomised controlled trials (RCTs) as a vehicle through which to explore complex social phenomena.

This paper, citing the IMAGE project throughout, makes a strong case for much greater use of RCTs. It argues that RCTs are not only about 'what works'. If sufficient consideration is given to how intervention components interact with each other and with local contexts, RCTs can also provide a better understanding of the social world. This in turn leads to greater insights into issues such as what works for whom, in what context and through which pathway.

The paper argues that such ‘realist’ trials should aim to:

  • Examine the effects of intervention components separately and in combination, for example using multi-arm studies and factorial trials,
  • Explore mechanisms of change, for example analysing how pathway variables mediate intervention effects,
  • Use multiple trials across contexts to test how intervention effects vary with context,
  • Draw on complementary qualitative and quantitative data,
  • Be oriented towards building and validating ‘mid-level’ program theories that would set out how interventions interact with context to produce outcomes

 The paper is in press and available online via institutional access.

Filter by