Epidemiologists use specific measures to quantify disease frequency and associations: - Incidence: The number of new cases of a disease in a defined population over a specified period. - Prevalence: The total number of cases (new and existing) of a disease in a population at a given time. - Relative Risk (RR): The ratio of the incidence rate of a disease in an exposed group to the incidence rate in an unexposed group. - Odds Ratio (OR): The odds of exposure among cases compared to the odds of exposure among controls.
