Understanding the complexity of surgical procedures in RCTs: a pilot study to test the application of the MRC framework for evaluating complex healthcare interventions in the operating theatre

Background Several methodological challenges make randomised trials (RCTs) in surgery difficult, and whether surgical interventions are themselves complex is an issue that requires further exploration [1]. Surgical interventions have multiple concomitant parts that may independently and inter-dependently influence outcomes such as the operation itself, surgeon expertise and contextual factors such as team working and elements of preand postoperative care. Trials that have failed to account for this complexity may be criticised and results not accepted or implemented. The MRC framework for developing and evaluating complex healthcare interventions highlights the need to use qualitative methods to define and identify individual active components of interventions during early stages of trial design [2]. This study piloted application of the MRC framework in the development of a surgical intervention within an ongoing RCT.