9
Analytic Epidemiology
•Causality is typically achieved by establishing hypotheses and formally evaluating these hypotheses
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•The observed outcome of a subgroup of people with a particular exposure is compared to the expected outcome of the population as a whole
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• Statistical methods are used to determine if the difference between the observed outcome and the expected outcome are significantly different
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•If so, there is likely to be a causal relationship between exposure and the outcome
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Speaking Points

•The determination of why disease occurs is typically achieved by establishing hypotheses and formally evaluating these hypotheses using comparison groups

•The observed outcome (for example, rate of disease) of a subgroup of people with a particular exposure (for example, people who ate at a particular restaurant on a particular day) is compared to the expected outcome of the population as a whole. Epidemiologists then use formal statistical methods as a tool to determine if the difference between the observed outcome and the expected outcome are significantly different. If so, one can conclude that there is likely to be a causal relationship between that particular exposure and the outcome.