Disease Rates

Question 1

Attributable risk

Answer 1

The attributable risk is the rate in the exposed group minus the rate in the unexposed group. For example the attributable risk for lung cancer in smokers is the rate of lung cancer in smokers minus the rate of cancer in non smokers. Essentially it tells you what proportion of deaths in the exposed group were due to the exposure.

Question 2

Population attributable risk

Answer 2

The population attributable risk can be described as the reduction in incidence that would be observed if the population were entirely unexposed. For instance how would the incidence of lung cancer change if everyone stopped smoking? It can be calculated by multiplying the attributable risk by the prevalence of exposure in the population.

Question 3

Attributable proportion

Answer 3

The attributable proportion is the proportion of the disease that would be eliminated in a population if its disease rate were reduced to that of the unexposed group.