The disease detectives. Pt. 1, Epidemiology I; the Broad Street pump.

Jolyon Jenkins discusses epidemiology. He starts with the apocryphal story of Dr John Snow taking the handle off the pump in Soho. Snow did connect drinking water and cholera in 1850s London by carrying out a test on a population of 300,000 whose water was supplied by two companies. Those drinking water from the Lambeth Co., which drew uncontaminated water from Surbiton, did not get cholera. Van der Brucke says one must have a plausible theory when doing epidemiology, as all data is theory loaded. The real hero of epidemiology is William Farr, the statistical analyst at the General Registry Office, who recorded 'cause of death' statistics. Since 20th century, morbidity statistics have been used for assessing chronic disease patterns.