At the end of the 1950s,

CIOMS organised a meeting under the joint auspices of the UN Educational, Scientific and Cultural Organisation (UNESCO) and the World Health Organization (WHO), “to discuss the principles, organization and scope of “controlled clinical trials”, which must be carried out if new methods or preparations used for the treatment of disease are to be accurately assessed clinically”.  The meeting took place March 1959 in Vienna, under the chairmanship of Austin Bradford Hill, at that time director of the UK Medical Research Council’s Statistical Research Unit. In spite of some hesitations the proceedings were published in English by Blackwell in 1960 under the title of Controlled Clinical Trials, and in French under the title Les essais thérapeutiques cliniques: méthode scientifique d’appréciation d’un traitement.
The 1959 meeting was a methodological landmark. Read more about it here.