Epi Quiz, Chapter 6

(1) Match the definitions below with one of the following terms: Cumulative incidence; Incidence density; Prevalence; Proportion; Rate

Term	Definition
A fraction in which the numerator is a subset of the denominator
The cross-sectional proportion of people in a population with a disease or condition.
The proportion of people in a population who develop a disease or condition over a given period of time.
The rate at which new events occur in a population.
The change in one unit relative to another (e.g., miles per hour, cases per year)

(2) A study of breast cancer begins with random sample of 10,000 women 50-years of age. Of these, 100 had been treated for or are currently being treated for breast cancer. The remaining women are followed for five years. During the follow-up interval, 250 women develop breast cancer.

(A) Calculate the prevalence of breast cancer at the beginning of the study. Show all work.

(B) Calculate the five-year cumulative incidence of breast cancer in this age group.

(C) Calculate the approximate incidence density of breast cancer.