1. Validity is...

Group of answer choices

• A relationship that describes cause and effect

• The degree to which a study truthfully reflects the specific association a researcher is attempting to measure

• The ability of a test to give the same results under similar conditions over time

• The systematic bias in selecting participants in your experimental study

2. Systematic error can be predicted whereas random error cannot.

Group of answer choices

• True

• False

3. The researchers conducted a prospective cohort study of the association between exposure to industrial glues and respiratory problems in children. The study included 55 children. What is the greatest problem in this study?

Group of answer choices

• Random error because of the very small size of the study

• Confounding because of the very small size of the study

• Selection bias because the very small size of the study

• Information bias because the very small size of the study

4. In 2009, the Philadelphia Department of Public health (PDPH) was interested in studying the risk factors associated with heart disease. They recruited two cohorts of participants. A total of 2,648 participants were recruited for each cohort from the City of Philadelphia. The participants were asked if they consumed read meat (exposure) in 2009 at the beginning of the study. In 2019, staff from PDPH searched the participants' medical records to see who had developed heart disease. The following table summarizes what they found:

FIRST COHORT - Table 1: Meat consumption and heart disease among Cohort 1 participants in Philadelphia, 2019.

	Heart disease (Disease)	No heart disease (No disease)	Total
Eat red meat (Avg. Age 75)	1,048	211	1,259
Do not eat red meat (Avg Age 30)	259	1,130	1,389
Total	1,307	1,341	2,648

Calculate the cumulative risk of the exposed

Group of answer choices

• 4.05

• 4.97

• 0.80

• 0.83

5. In 2009, the Philadelphia Department of Public health (PDPH) was interested in studying the risk factors associated with heart disease. They recruited two cohorts of participants. A total of 2,648 participants were recruited for each cohort from the City of Philadelphia. The participants were asked if they consumed read meat (exposure) in 2009 at the beginning of the study. In 2019, staff from PDPH searched the participants' medical records to see who had developed heart disease. The following table summarizes what they found:

FIRST COHORT - Table 1: Meat consumption and heart disease among Cohort 1 participants in Philadelphia, 2019.

	Heart disease (Disease)	No heart disease (No disease)	Total
Eat red meat (Avg. Age 75)	1,048	211	1,259
Do not eat red meat (Avg Age 30)	259	1,130	1,389
Total	1,307	1,341	2,648

Calculate the cumulative incidence of the unexposed

Group of answer choices

• 0.25

• 0.19

• 0.20

• 0.23

6. Calculate the appropriate measure of comparison from the questions above.

Group of answer choices

• OR = 4.05

• RR = 4.05

• )R = 4.46

• RR = 4.46

7. What is the interpretation of the above measure of association?

Group of answer choices

• Those who do not consume red meat have 4.37 times the risk of heart disease than those who consume red meat

• Those who consume red meat have 4.37 times the risk of heart disease than those who do not consume red meat

• Those who consume red meat have 4.05 times the risk of heart disease than those who do not consume red meat

• Those who do not consume red meat have 4.05 times the risk of heart disease than those who consume red meat

8. Some members of this cohort who ate red meat were uncomfortable reporting that they ate red meat and instead reported no red meat consumption. What type of error is this?

Group of answer choices

• Information bias

• Confounding

• Random error

• Selection bias

9. In 2009, the Philadelphia Department of Public health (PDPH) was interested in studying the risk factors associated with heart disease. They recruited two cohorts of participants. A total of 2,648 participants were recruited for each cohort from the City of Philadelphia. The participants were asked if they consumed read meat (exposure) in 2009 at the beginning of the study. In 2019, staff from PDPH searched the participants' medical records to see who had developed heart disease. The following table summarizes what they found:

SECOND COHORT - Table 2: Meat consumption and heart disease among Cohort 2 participants in Philadelphia, 2019.

	Heart disease (Disease)	No heart disease (No disease)	Total
Eat red meat (Age Avg. 30)	55	1,334	1,389
Do not eat red meat (Age Avg 75)	202	1,057	1,259
Total	257	2,391	2,648

Calculate the cumulative incidence for the exposed.

Group of answer choices

• 0.02

• 0.21

• 0.04

• 0.27

10. SECOND COHORT: Question: In 2009, the Philadelphia Department of Public health (PDPH) was interested in studying the risk factors associated with heart disease. They recruited two cohorts of participants. A total of 2,648 participants were recruited for each cohort from the City of Philadelphia. The participants were asked if they consumed read meat (exposure) in 2009 at the beginning of the study. In 2019, staff from PDPH searched the participants' medical records to see who had developed heart disease. The following table summarizes what they found:

Table 2: Meat consumption and heart disease among Cohort 2 participants in Philadelphia, 2019.

	Heart disease (Disease)	No heart disease (No disease)	Total
Eat red meat (Age Avg. 30)	55	1,334	1,389
Do not eat red meat (Age Avg 75)	202	1,057	1,259
Total	257	2,391	2,648

Calculate the cumulative incidence for the unexposed.

Group of answer choices

• 0.79

• 3.67

• 0.16

• 0.19

11. Calculate the appropriate measure of comparison from the question above.

Group of answer choices

• RR = 0.25

• RR = 0.22

• OR = 0.22

• OR = 0.25

12. What is the interpretation of the above measure of comparison?

Group of answer choices

• Those who do not consume red meat have 0.25 times the risk of heart disease than those who consume red meat

• Those who do not consume red meat have 0.25 times the risk of heart disease than those who consume red meat

• Those who consume red meat have 0.25 times the risk of heart disease than those who do not consume red meat

• Those who consume red meat have 0.22 times the risk of heart disease than those who do not consume red meat

13. Many people who were originally recruited for this study about the association between red meat and ischemic heart disease, were feeling weak or too sick so they refused to participate in the study. What type of error is this?

Group of answer choices

• Confounding

• Information bias

• Selection Bias

• Random error

14. Compare the relative risks from the two cohorts (tables 1 & 2): What factor in your opinion led to this difference in the relative risks?

Group of answer choices

• The age group of those who eat red meat in Table 1 is lower than the age group of those who eat red meat in Table 2, leading to a higher relative risk. Age seems to be a confounder

• None of the above

• The age group of those who eat red meat in Table 1 is higher than the age group of those who eat red meat in Table 2, leading to a lower relative risk. Age seems to be a confounder

• The age group of those who eat red meat in Table 1 is higher than the age group of those who eat red meat in Table 2, leading to a higher relative risk. Age seems to be a confounder