ANTC67H3 Chapter Notes - Chapter 3: Field Trial, Statistical Power, Odds Ratio
Document Summary
Allow nature to take its course while the researcher does not intervene. Involves the attempt to change a disease determinant such as an exposure or a behaviour or progress of disease through a treatment: rct, field trials = participants are healthy people, community trials = participants are communities themselves. Health status of a community base on available data or on data obtained from surveys. Usually the first step in epidemiological studies. Look at morality in relation to age, sex or ethnicity over a time period or in various countries. Unit of analysis = groups of people rather than individuals. Can be done by comparing populations in different places at the same time or same population in one place at different times. Time series may reduce some of the socioeconomic cofounding this is a potential problem in ecological studies. Very difficult to interpret since it seldom possible to examine directly the various potential explanations for findings.
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