RCTs from within: The influence of scientific rigour, randomisation and chance on the credibility of reported findings

In this chapter, we shall consider a published randomised controlled trial (RCT) involving a controversial retroactive intervention as the basis for highlighting statistical flaws that can creep into the reporting and interpretation of RCTs more generally. These contributions support the standpoint that even for an RCT, the credibility of the reported findings relies on the correct implementation and interpretation of statistical procedures. Within medicine and other health professions, this ought to complement existing training in critical appraisal and data skills by encouraging an interrogation of the more formal aspects of applying and reporting statistics, even at a relatively basic level. We shall also consider data from a large international stroke trial to assist in visualising the influence of random allocation error (as a specific form of random error) on RCT results. This will serve as a concrete example illustrating that for a well-designed RCT, by the very nature of simple randomisation, statistical significance can arise in the form of a false positive favouring the effectiveness of the intervention when the null hypothesis of no effect is true. From a philosophical perspective, we shall also consider an alternative approach to that of merely equating chance events with accidental events. This will include both recognising that such events are an inevitable product of simple randomisation and rejecting the chance-cause dichotomy.