Final answer:
Relative risk measures the association between an exposure and a health outcome in epidemiology. It is calculated by dividing the incidence in the exposed group by the incidence in the non-exposed group. Expressing rates using percentages or multipliers help to clarify the impact on the population.
Step-by-step explanation:
Understanding Relative Risk in Epidemiology
In epidemiology and public health, the concept of relative risk is essential for comparing the health status and disease frequencies within populations or groups. To calculate relative risk, one would divide the incidence rate of a health event in the group exposed to a certain factor by the incidence in the non-exposed group (RR = incidence in exposed group / incidence in non-exposed group). This method sheds light on the association between exposures and health outcomes, oftentimes representing the strength of such an association through risk ratios that are greater or less than one, indicating higher or lower risk, respectively.
When epidemiologists use a case-control study, they can assess risk factors for diseases and attempt to identify potential causes, such as in a sporadic outbreak of a food-borne illness. The importance of calculating relative risk comes from its ability to evaluate if there is a significant association between risk factors like smoking and health impacts like cardiovascular disease. It is crucial to express these rates in a way that emphasizes their impact, often by using percentages or multipliers that provide a more comprehensible figure regarding the number of individuals affected per certain population size.