On the problems of mixing RCTs with qualitative research: the case of the MRC framework for the evaluation of complex healthcare interventions

In the perceived hierarchy of research designs, the results from randomised controlled trials are considered to provide the highest level of evidence. Indeed, these trials have been upheld as the gold standard in research. The benefits and limitations of the randomised controlled trial as a method of evaluating the effectiveness of healthcare interventions are presented. The paper then examines the different levels of complexity within healthcare interventions and the problems this poses in determining effectiveness. In an effort to provide a solution to this problem, the Medical Research Council produced a framework to assist investigators to develop and evaluate complex healthcare interventions. The framework is described with reference to an example of implementing and evaluating protocols for weaning patients in the intensive care unit. The framework is critiqued on the basis that it involves an ambiguous or contradictory ontology, which fails to articulate the relationship between the positivism of randomised controlled trials with the relativism of qualitative approaches. It is concluded that the use of realist strategies in combination with randomised controlled trials provides the most coherent solution to this quandary.