Epidemiology Quiz

Covers Chapters 6 (Incidence & Prevalence) & 8 (Measures of Association)

1.	Match each definition below with one of these statistics:

(A) Prevalence (B) Incidence (D) Relative Risk (E) Risk Difference (F) Attributable Fraction

_____	This statistic describes the relative excess in risk associated with an exposure. When it is 1, there is no excess in risk.

_____	This statistic describes the probability that someone selected at random from the population will have the disease. It is measured as the proportion of people in the population who have the disease.

_____	This statistic describes the excess in risk in absolute terms. It shows the additional number of cases expected per m exposures.

_____	This statistic measures the risk of acquiring the disease over a set period of time. It may be measured as a rate or a proportion.

2.	A study starts with 5,000 people. Of these, 125 have the disease in question. What is the prevalence of disease per 1000 people? (Show work).

3.	A study starts with 4,875 health people. Over the next 2 years, 75 develop the disease. What is the incidence rate (density) of disease over the study period? (Show work.)

4.	A study wants to assess the putative association talking on a cellular phone while driving and traffic accidents. In so doing, it finds that people with cellular phones have accidents at the rate of 11.1 per 10,000 miles. People who do not have cellular phones have accidents at the rate of 8.6 per 10,000 miles. Calculate the risk difference associated with cellular phone use and, carefully, in plain terms, interpret what this result means.