NR 503 EPIDEMIOLOGY MIDTERM EXAM
1. The incidence and prevalence rates of a chronic childhood illness for a
specific community are given below.
Based on the data, which of the following interpretations best describes
disease X?
Correct! :The duration of disease is becoming longer.
2. A disease has an incidence of 10 per 1,000 persons per year, and 80% of
those affected will die within 1 year. Prior to the year 2000, only 50% of
cases of the disease were detected by physician diagnosis prior to death. In
the year 2000, a lab test was developed that identified 90% of cases an
average of 6 months prior to symptom onset; however, the prognosis did not
improve after diagnosis. Which statement is true concerning the disease-
specific mortality rate after the development of the lab test?
Correct! :The mortality rate for the disease is the same in 2000
3. Among those who are 25 years of age, those who have been driving less than
5 years had 13,700 motor vehicle accidents in 1 year, while those who had
been driving for more than 5 years had 21,680 motor vehicle accidents
during the same time period. It was concluded from these data that 25-year-
olds with more driving experience have increased accidents compared to
those who started driving later. This conclusion is:
Correct Answer: Incorrect because rates are not reported
4. In a country with a population of 16 million people, 175,000 deaths occurred
during the year ending December 31, 2005. These included 45,000 deaths
from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume
that the population remained constant throughout the year. Not all 135,000
cases of TB were contracted during 2005. Which of the following statements
is true?
Correct! : None of the above
, 5. Which of the following is a condition which may occur during the
incubation period?
Correct! : Transmission of infection
6. Test A has a sensitivity of 95% and a specificity of 90%. Test B has a
sensitivity of 80% and a specificity of 98%. In a community of 10,000
people with 5% prevalence of the disease, Test A has always been given
before Test B. What is the best reason for changing the order of the tests?
Correct! : The total number of false positives found by both tests is
decreased if Test B is given first
7. In 2001, a state enacted a law that required the use of safety seats for all
children under 7 years of age and mandatory seatbelt use for all persons. The
table above lists the number of deaths due to motor vehicle accidents
(MVAs) and the total population by age in 2000 (before the law) and in
2005 (4 years after the law was enacted).
Based on the information in the table, it was reported that there was an
increased risk of death due to MVAs in the state after the law was passed.
These conclusions are:
Correct Answer : Correct, because both the total and the age-adjusted
mortality rates are higher in 2005 than in 2000
8. Which of the food items (or combination of items) is most likely to be the
infective item(s)?
Correct! : Ice cream only
9. Which of the following reasons can explain why a person who did not
consume the infective food item got sick?
Correct! :All of the above
10.Which of the following are examples of a population prevalence rate?
Correct! : The number of persons with hypertension per 100,000 population
1. The incidence and prevalence rates of a chronic childhood illness for a
specific community are given below.
Based on the data, which of the following interpretations best describes
disease X?
Correct! :The duration of disease is becoming longer.
2. A disease has an incidence of 10 per 1,000 persons per year, and 80% of
those affected will die within 1 year. Prior to the year 2000, only 50% of
cases of the disease were detected by physician diagnosis prior to death. In
the year 2000, a lab test was developed that identified 90% of cases an
average of 6 months prior to symptom onset; however, the prognosis did not
improve after diagnosis. Which statement is true concerning the disease-
specific mortality rate after the development of the lab test?
Correct! :The mortality rate for the disease is the same in 2000
3. Among those who are 25 years of age, those who have been driving less than
5 years had 13,700 motor vehicle accidents in 1 year, while those who had
been driving for more than 5 years had 21,680 motor vehicle accidents
during the same time period. It was concluded from these data that 25-year-
olds with more driving experience have increased accidents compared to
those who started driving later. This conclusion is:
Correct Answer: Incorrect because rates are not reported
4. In a country with a population of 16 million people, 175,000 deaths occurred
during the year ending December 31, 2005. These included 45,000 deaths
from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume
that the population remained constant throughout the year. Not all 135,000
cases of TB were contracted during 2005. Which of the following statements
is true?
Correct! : None of the above
, 5. Which of the following is a condition which may occur during the
incubation period?
Correct! : Transmission of infection
6. Test A has a sensitivity of 95% and a specificity of 90%. Test B has a
sensitivity of 80% and a specificity of 98%. In a community of 10,000
people with 5% prevalence of the disease, Test A has always been given
before Test B. What is the best reason for changing the order of the tests?
Correct! : The total number of false positives found by both tests is
decreased if Test B is given first
7. In 2001, a state enacted a law that required the use of safety seats for all
children under 7 years of age and mandatory seatbelt use for all persons. The
table above lists the number of deaths due to motor vehicle accidents
(MVAs) and the total population by age in 2000 (before the law) and in
2005 (4 years after the law was enacted).
Based on the information in the table, it was reported that there was an
increased risk of death due to MVAs in the state after the law was passed.
These conclusions are:
Correct Answer : Correct, because both the total and the age-adjusted
mortality rates are higher in 2005 than in 2000
8. Which of the food items (or combination of items) is most likely to be the
infective item(s)?
Correct! : Ice cream only
9. Which of the following reasons can explain why a person who did not
consume the infective food item got sick?
Correct! :All of the above
10.Which of the following are examples of a population prevalence rate?
Correct! : The number of persons with hypertension per 100,000 population
