discussion

1. A study of prostate cancer was initiated in Des Moines, Iowa, in the beginning of January 2015.  One-thousand (1,000) men, 55-64 years of age, with no prior evidence of prostate cancer were enrolled in this study.  The men were then followed by the investigators for four years until the end of the 2018.  Each year during the study, the men were examined and tested for the presence of prostate cancer.  The results of the annual examinations revealed the following:

1. 10 cases were confirmed after 1 year
2. 15 additional cases were confirmed after 2 years
3. 20 additional cases were confirmed after 3 years
4. 25 additional cases were confirmed after 4 years

What was the total number of person-years for this study? (1 points).  What is the person-time incidence rate of prostate cancer in this group? (1 points)

1. A young child is looking into a gumball machine filled with yellow, red, orange, and blue gumballs. There are 10 yellow, 6 red, 18 orange, and 20 blue gumballs in the machine. If the child puts in a quarter, what are the odds of the following? (4 points)

1. A red gumball?

1. A blue or orange gumball?

Now what is the probability of the same events:

1. What is the probability of getting a red gumball?

1. What is the probability of getting a blue or orange gumball?

1. The figure below shows a hypothetical population with 10 people, all of whom were at risk at the start of a 1-year follow-up observation period: (2 points)

1. What is the total person-months at risk? ____________________

1. Calculate the incidence rate for this problem (there is more than one way to express this) __________________
2. A prevalence survey conducted from January 1st through December 31st, 2018 identified 1,000 cases of schizophrenia in a city of 2 million persons. The incidence rate of schizophrenia in the population is 5 per 100,000 person each year. What percent of the 1,000 cases were newly diagnosed in 2018? (1 point)
3. The table below provides hypothetical data regarding the prevalence of diabetes in two counties in the United States. Based on 2020 prevalence (percentage), which of the two counties had a higher burden of disease from diabetes? (1 point)

Diabetes Data

	Est. Total Population of July 1, 2020	Total # of Cases of Diabetes in 2020
County A	11,020,000	356,289
County B	3,900,000	253,612

Show your work:

• Answer: County A or County B

Note:

The formula for person time incident rate is the number of cases over person time,

For question 5: Just divided the cases by population.

For question 4: Divided the population by the 100,000 person years then multiplied the answer by 5 to get the new cases them divided that 1000 to get the answer.