Answering Criticisms of RCTs

In recent years, there have been several papers published, mainly by philosophers, criticising randomised controlled trials (RCTs). These include criticisms of their logic and structure as well as of individual published studies. In order to address these criticisms, this chapter reviews the history of RCTs and how their methodology has developed in recent years and illustrates aspects of their design and analysis with real examples. Against this background, it examines the three main perspectives from which philosophers criticise RCTs: objections to randomisation, promotion of observational studies and objections to lack of generalisability. It is argued that some of the objections to randomisation do not withstand scrutiny. The claim that RCTs can be replaced by observational studies is also disputed, while it is acknowledged that observational studies can contribute to treatment decisions. The criticism that the results of RCTs do not always transfer to other settings is one that no one could disagree with. Recommendations on how the results of trials should be registered and reported need to be followed to help decisions as to whether the result could work elsewhere.