van Helmont’s proposal for a randomised comparison of treating fevers with or without bloodletting and purging

Around the year 1643, Joan Baptista van Helmont, a Flemish chemist, alchemist and physician who had devised what he claimed to be a new form of medicine, proposed a ‘challenge’ to traditional Galenic physicians to compare treatment of fever by traditional methods and by a regime which did not involve bloodletting and purging. Two groups of patients were to be treated and ‘casting of lots’ was to be used – in some way not specified in detail – to decide who received which treatment. This ‘challenge’ has been regarded as the first proposal for the use of randomisation in a clinical trial.

The demise of bloodletting

Bloodletting was a practice favoured by doctors and barber-surgeons
for many centuries, and is now, perhaps surprisingly, still employed for a few
specific indications. The effectiveness of bloodletting for treating diseases such as pneumonia was convincingly challenged in the mid-nineteenth century, but medical conservatism ensured the practice continued well into the twentieth century. As late as 1942, a famous medical textbook considered bloodletting appropriate treatment for pneumonia.

KEYWORDS Bloodletting, lancets, pneumonia, leeches, transfusion