The development and evaluation of complex interventions within randomised controlled designs is a challenging area in health services research. The process usually entails a pilot phase to confirm the feasibility and potential effectiveness of the design before embarking on large and costly trials. However, the focus is often more on the study design and measures than on the theoretical base and extent to which the intervention can be appropriately applied. In this article, we use a case study to describe an approach to pilot work that addresses this gap.
- Interventions are often defined pragmatically and lack any clear theoretical basis, which limits generalisability
- Implementation is rarely described, which limits understanding of why an intervention is or is not locally successful
- Integration of qualitative methods within pilot trials can help interpret the quantitative result by clarifying process and testing theory
- This approach defines three levels of understanding: the evidence and theory which inform the intervention, the tasks and processes involved in applying the theoretical principles, and people with whom, and context within which, the intervention is operationalised
- A case study shows how this novel method of programme development and evaluation can be applied