ABSTRACT
This chapter discusses the complexities highlighted in medical research, knowledge and practice. It shows the import of the distinction between frequentist and subjectivist interpretations of probability and the importance of the vagaries of inductive inference and of causal claims. The chapter deals with highly contentious material. Although randomised controlled trials (RCTs) have been dubbed by many as the gold standard of evidence for therapeutic efficacy in clinical medicine, there are other study designs that are frequently used. The chapter also discusses Bayesian methods somewhat superficially for the better understanding the mathematical background required to follow a more detailed account. It recognises that there is no strict either–or involved but the current resistance to Bayesian methods and entrenched support for RCTs require a strong stance in favour of Bayesian methods. Finally, the chapter returns to the quest for causality in clinical research.
