The study of the incidence, prevalence and distribution of diseases disorders and infections in specified populations (e.g., as defined by age, sex, occupation), with the aim of providing information about their causes and how they might be controlled. Other important features of epidemiology are the identification of risk factors for particular diseases (e.g., pre-eclampsia) and disorders (e.g., cerebral palsy), and its crucial role in evidence-based medicine. It can be thought of as the who, where, when, what and why of diseases etc.: who has it, where they are located geographically and in relation to each other, when it is occurring, what the cause is, and why it occurred. The founding event of epidemiology is usually assigned to the successful effort of John Snow (1813-1858) to suppress the outbreak of cholera in London’s Soho district in 1854 by sabotaging an infected water pump in Broad Street. Another important figure was Florence Nightingale (1820-1910) who kept innovative statistical records of diseases and infections incurred by soldiers during the Crimean War (1854-1856).
See ‘At-risk’ concept, Attributable fraction, Case-comparison design, Cerebral palsy, Cumulative evidence, Epidemiological studies, Incidence, Odds ratio, Population (biology and ecology), Pre-eclampsia, Prevalence, Rate ratio, Register, Risk factors