John Snow and Evidence Based Analysis
John Snow
- English physician
- Leader in the development of anaesthesia and medical hygiene
- Founders of modern epidemiology and early germ theory
1854 Broad Street cholera outbreak
- A severe outbreak of cholera in 1854 near Broad Street in London
- Background: the 1846–1860 cholera pandemic happening worldwide
- The outbreak killed 616 people
Two theories
- Miasma theroy
- Particles in the air
- Dr William Farr, commissioner for the 1851 London census and a member of the General Register’s Office,
- Miasma arose from the soil surrounding the River Thames
- Germ theory
- A germ cell that had not yet been identified, via water
- John Snow
John Snow’s investigation
Mapping out the cases
“all the deaths had taken place within a short distance of the [Broad Street] pump”.
Statistics: Cholera rate in sewage-polluted water serving area is 14 times those from upriver
Evidence is power
- John Snow’s invetigation
- Government officals replaced the Broad Street pump
- He convinced William Farr, his opponent, to accept the germ theory
- Government officals replaced the Broad Street pump
- The power of data visulization
- The create of double-blind experiment
- Founding of epedimiology
Further readings
- Tulchinsky, Theodore H. 2018. “Chapter 5 - John Snow, Cholera, the Broad Street Pump; Waterborne Diseases Then and Now.” In Case Studies in Public Health, edited by Theodore H. Tulchinsky, 77–99. Academic Press. https://doi.org/10.1016/B978-0-12-804571-8.00017-2.
- Scott Cunningham. 9.1 John Snow’s Cholera Hypothesis in Cause Inference: The Mixtape. https://mixtape.scunning.com/09-difference_in_differences