Questions: The History of Medicine: From Humors to Evidence-Based Practice

Question 1

Hippocratic medicine relied on the 'four humors' theory. What were the four humors and what treatment logic did this theory produce?

Model answer: The four humors were blood, phlegm, yellow bile, and black bile. Disease resulted from an imbalance among them; treatment aimed to restore balance. Excess blood was treated by bloodletting (phlebotomy); excess phlegm by expectorants; excess bile by purging. The theory persisted for nearly two millennia not because it cured patients but because it was a coherent explanatory framework that gave physicians a role and a rationale. Bloodletting in particular likely harmed patients by weakening them further.

Humoral theory illustrates how wrong medical theories can persist when there is no rigorous method for evaluating outcomes. Without controlled comparison between treatment and no treatment, physicians could not recognize that their interventions were ineffective or harmful.

Question 2

What was the significance of the randomized controlled trial (RCT) for medical practice, and when was it introduced?

• A. The RCT was introduced by Hippocrates around 400 BCE as the gold standard for herbal medicine
• B. The first recognized RCT was conducted in 1948 to test streptomycin for tuberculosis, establishing experimental comparison as medicine's evidence standard
• C. RCTs were standard practice by the 19th century due to Pasteur's influence
• D. RCTs were introduced in the 1970s specifically to evaluate surgical procedures

Answer: (B)

The Medical Research Council's 1948 trial of streptomycin for tuberculosis, designed by Austin Bradford Hill, is recognized as the first modern RCT. Patients were randomly assigned to treatment or control groups, eliminating selection bias. The result — streptomycin reduced mortality — was convincing precisely because randomization controlled for confounders. This methodological innovation, more than any drug discovery, transformed medicine's ability to evaluate interventions.

Question 3

Alexander Fleming discovered penicillin in 1928. Why did it take over a decade before penicillin became available as a treatment?

Model answer: Fleming observed in 1928 that a mold (Penicillium) killed bacteria on a culture plate, but he could not purify or stabilize the active substance and largely set the observation aside. Penicillin's clinical development required Howard Florey, Ernst Chain, and Norman Heatley at Oxford to develop methods for purifying, concentrating, and testing the drug — work completed by 1940-1941. Large-scale production required industrial fermentation techniques developed with American pharmaceutical companies under wartime pressure. The first patients were treated in 1941; mass production for military use began in 1943. Basic discovery and clinical application required very different capabilities.

The penicillin story illustrates the gap between discovery and clinical application, and the role of wartime industrial mobilization in scaling up pharmaceutical production.

Question 4

The history of medicine shows steady, continuous progress from ancient ignorance toward modern scientific understanding.

• T. True
• F. False

Answer: False

Medical history includes significant regressions and long stagnations. Arabic physicians of the 9th-12th centuries (Al-Razi, ibn Sina) often had better clinical practices than European physicians of the same era. Bloodletting remained standard treatment for centuries after its harms were visible. Germ theory was resisted for decades after Semmelweis demonstrated infection transmission. Progress was not linear; it required both theoretical breakthroughs and institutional changes in how medical claims were evaluated and transmitted.

Question 5

What is evidence-based medicine (EBM), and what problem was it designed to address?

Model answer: Evidence-based medicine, articulated by Archibald Cochrane in 1972 and formalized in the 1990s by a group at McMaster University, holds that clinical decisions should be based on systematic review of the best available evidence rather than expert opinion, tradition, or pathophysiological reasoning. The problem it addressed was the widespread use of treatments that had never been rigorously tested — some of which were harmful. Cochrane's founding insight was that medicine wasted enormous resources (and harmed patients) through interventions whose efficacy had never been demonstrated by randomized trial.

EBM was partly a political project: it challenged the authority of senior clinicians to prescribe based on personal experience and pushed for systematic evidence. It transformed medical practice in many areas while generating ongoing debates about what kinds of evidence count.