Semmelweis is the standard case of a man who was right and was rejected. He noticed that the clinic staffed by doctors and students killed more mothers than the one staffed by midwives, and he blamed the autopsy room. Nobody ever ran the statistics on his own data. What happens when you do?
It holds up, and the dates line up with it. A review of maternal mortality from 1784 to 1858 found four turning points. Mortality rose when arrived in 1823. was deadlier than Clinic 2 after 1840. handwashing in 1847 brought mortality down, and it rose again once he left Vienna in 1850.
Historians generally accept that Ignaz Semmelweis was the first to identify how moved from person to person. What nobody had reported, as the authors of this review point out, is an appropriate statistical analysis of the data he collected for that theory.
So they analyzed mean annual percent maternal mortality rates for the Allgemeines Krankenhaus and the Dublin maternity hospitals, across the years 1784 to 1858. That brackets his career on both sides and gives the record a comparison outside Vienna.
Four turning points come out of it. The introduction of pathological anatomy in Vienna in 1823 was associated with increased mortality. After 1840, mortality was higher in Clinic 1, staffed by male obstetricians and medical students who attended autopsies, than in Clinic 2, staffed by midwives who did not.
Then the chlorine. Handwashing introduced in Clinic 1 in 1847 reduced mortality, and the cessation of handwashing after Semmelweis left Vienna in 1850 was associated with it rising again. The analysis supports his claim that cadaveric particles adhering to the hand had caused the preponderant mortality in the first clinic.
wat. Mortality fell when the doctors washed their hands in chlorine and rose again when Semmelweis left Vienna.
wat wat
A famous story about scientific stubbornness turns out to have waited 160 years for somebody to test its central claim properly.
How do we know?
Noakes and colleagues analyzed mean annual percent maternal mortality rates for the Vienna Allgemeines Krankenhaus and the Dublin maternity hospitals, then lined the figures up against the date of each change in practice.
What is still unknown
These are historical mortality records compared against dates, not a controlled trial, and association over time is weaker evidence than assignment.
Learn something?
Where to next
An air dryer spreads more bacteria than a paper towel. Is that always true?hygiene
The food hit the floor and you grabbed it. Do five seconds really save it?hygiene
Why do bacteria hold on better to a paper note than a plastic one?hygiene