Question
Relationship between prevalence and incidence
a. In a steady state population, what condition is required for the following formula to hold?
Prevalence (P) ≈ Incidence density (ID) * duration of disease (D)
b. Which equation can be used to link prevalence and incidence density in a steady state population when the condition from part a) is not met?
c. If the cumulative incidence of H1N1 (a specific strain of influenza) is 20.5/100,000 cases per year, and the duration of the flu is 2 weeks, what is the annual prevalence?
(hint: Calculate the prevalence, incidence, or duration using the equations.)
