This thesis examines the rhetoric employed in the debate over the proper means to assess therapeutic efficacy during the first half of the twentieth century. I explore a number of therapeutic investigations including the debate in 1925 over the consumption of raw pancreas as a treatment for diabetes, the MRC’s investigation of ultraviolet light therapy in 1928, the MRC trial of serum therapy in pneumonia during the early 1930s, and the MRC’s wartime influenza vaccination trials during the 1940s.
The MRC’s streptomycin trial, published in 1948, provided a model for future work in studies of therapeutic efficacy. Prior to this, therapeutic trials were idiosyncratic affairs and the methodology of a proper clinical trial was neither unified nor codified. But the MRC nevertheless referred consistently to its own trials as ‘controlled’ throughout the first half of the twentieth century. The term ‘controlled’ encompassed an eclectic assortment of methodologies, and conveyed a number of different meanings, sometimes simultaneously. Much of my thesis is devoted to exploring these various meanings and the contexts in which they were used. The unifying characteristic which bound the divers uses of the term ‘controlled,’ was its use as a rhetorical device at a time when the authority to determine the proper means of testing a remedy was very much up for grabs. The MRC, by describing its own therapeutic experiments as ‘controlled,’ was exploiting the powerful rhetorical connotations of the term. Ultimately, the MRC’s ‘controlled trial’ became a construct – prior to 1948 there was no single methodology which could describe it, no published trial which could exemplify it, yet it existed as a rhetorical device which could be used to enhance the authority of a trial performed under the auspices of the MRC. The implications of this insight for current understanding of ‘controlled trials’ are discussed.