Year 1979: Results from the pharmacological treatment of Crohn's disease

In 1975, observational studies were still predominant. Many patients received salazopyrin, mercaptopurine or corticosteroids due to data from observational studies or those carried out on other conditions (extrapolating evidence to Crohn's disease, for example). This study marked a milestone in the research on Crohn's disease because it recognized the importance of conducting multicentre studies to enable the evaluation of sufficient numbers of patients. First the CDAI was designed for this study, making it possible to demonstrate that corticosteroids are much more effective than placebo in controlling Crohn's disease activity. But it also had very negative results. First, it made it necessary to use the CDAI in all studies in order to be able to compare them (with the tool's multiple defects and major subjective component). Second, it suggested that azathioprine is ineffective, almost certainly over a short observation period: just 15 years later it was shown that by waiting more weeks, thiopurines can be very useful for maintenance. It is often said that salazopyrin works on Crohn's disease of the colon, but it should be noted that endoscopy was a very rarely available or practised technique in 1979; therefore the trustworthiness of many of the diagnoses of colonic disease included should be doubted (there may be cases of ulcerative colitis). In any case, it ushered in the era of multicentre trials and serious design obstacles had to be resolved; a lesson in pride and generosity.