Different measures of association have been used to numerically express the link between exposure

Full Answer Section

      Measures of association can be used to answer a variety of questions, such as:

• How much more likely are people who are exposed to a risk factor to develop a disease?
• How much would the risk of disease be reduced if the exposure were eliminated?
• What proportion of cases of a disease are attributable to a particular risk factor?

Example of a Measure of Association: Relative Risk One common measure of association is relative risk (RR). RR is defined as the ratio of the risk of disease among exposed individuals to the risk of disease among unexposed individuals. It is a measure of the strength of the association between an exposure and a disease outcome. For example, a study might find that the RR of lung cancer among smokers is 10. This means that smokers are 10 times more likely to develop lung cancer than nonsmokers. RR can be used to assess the impact of public health interventions. For example, if a public health campaign is successful in reducing the number of smokers, we would expect to see a decrease in the RR of lung cancer. RR can also be used to develop and implement evidence-based policies. For example, if we know that smoking is a major risk factor for lung cancer, we can develop policies to discourage smoking, such as increasing cigarette taxes and banning smoking in public places. Other Measures of Association Other measures of association that are commonly used in public health decision making include:

• Absolute risk reduction (ARR): ARR is the difference in the risk of disease between exposed and unexposed individuals. It is a measure of the impact of an exposure on the risk of disease.
• Attributable risk (AR): AR is the proportion of cases of a disease that are attributable to a particular risk factor. It is a measure of the public health impact of an exposure.
• Odds ratio (OR): OR is a measure of the strength of the association between an exposure and a disease outcome that is often used in case-control studies.

Conclusion Measures of association are essential tools for public health decision makers. They provide information that can be used to identify risk factors for disease, assess the impact of public health interventions, and develop and implement evidence-based policies. Example of the Use of Relative Risk in Public Health Decision Making The following example shows how relative risk can be used in public health decision making: A study is conducted to assess the impact of a flu vaccination program on the risk of developing influenza. The study finds that the RR of influenza among vaccinated individuals is 0.5. This means that vaccinated individuals are half as likely to develop influenza as unvaccinated individuals. Public health officials can use this information to make decisions about the flu vaccination program. For example, they may decide to expand the program to reach more people or to make it easier for people to get vaccinated. Conclusion Measures of association are valuable tools for public health decision makers. They provide information that can be used to improve the health of the population.  

Sample Answer

   

Measures of association are used in analytical epidemiology to quantify the relationship between an exposure and a disease outcome. They are essential tools for public health decision makers, as they provide information that can be used to:

• Identify risk factors for disease.
• Assess the impact of public health interventions.
• Develop and implement evidence-based policies.