Deck 12: Estimating Risk: Is There an Association

Question 1

Unmatch the pairs.What is the estimated odds ratio of cases when analyzing this study as an unmatched case-control study design? Use the information from a case-control study table. Exposure Status by Disease Status

A) 0.50
B) 0.67
C) 1.00
D) 2.00
E) 2.25

Answer 1

E
The odds ratio of exposure among controls is found by dividing 1.5 (the odds of exposed people among cases) by the odds of exposed people among controls (2 over 3,which equals 2.25).

Question 2

The following table summarizes the findings of a cohort study.Participants were enrolled in January 1,2015,and followed up until December 31,2015.Researchers were interested in the effect of physical activity on cardiovascular disease. Based on the previous information,calculate the incidence per 1,000 per year of cardiovascular events among those who were categorized as physically active.

A) 14/1,000 per year
B) 25/1,000 per year
C) 28/1,000 per year
D) 75/1,000 per year
E) 99/1,000 per year

Answer 2

A
Incidence in that group is calculated by dividing the number of events over the total number of participants in that group (28/2,000 = 0.014).

Question 3

The following information summarizes the exercise status and obesity status in a case-control study.What are the odds of regular exercise in the obesity group? Use the following table to answer the question. Exercise Status by Obesity Status

A) 0.16
B) 0.26
C) 0.37
D) 0.44
E) 0.59

Answer 3

A
The number of regular exercise in the obesity group is 7,and the number of no exercise in the same group is 43.Therefore the odds of exercise in the obesity group is 0.16 (7 divided by 43).

Question 4

The following table summarizes the findings of a cohort study.Participants were enrolled in January 1,2015,and followed up until December 31,2015.Researchers were interested in the effect of physical activity on cardiovascular disease. Based on the previous information,calculate the relative risk of cardiovascular events for those who were physically active.

A) 0.38
B) 0.56
C) 1.50
D) 1.79
E) 2.68

Question 5

Which of the following measures represents the absolute risk of getting a disease?

A) Prevalence
B) Odds ratio
C) Risk ratio
D) Incidence
E) Risk difference

Question 6

Unmatch the pairs.What are the estimated odds of exposure in controls when analyzing this study as an unmatched case-control study design? Use the information from a case-control study table. Exposure Status by Disease Status
$$\begin{array} { | l | l | l| l } \hline \text { Pair no. } & \text { Cases } & \text { Controls } \\\hline 1 & \text { Exposed } & \text { Unexposed } \\\hline 2 & \text { Exposed } & \text { Exposed } \\\hline 3 & \text { Unexposed } & \text { Exposed } \\\hline 4 & \text { Exposed } & \text { Unexposed } \\\hline 5 & \text { Exposed } & \text { Unexposed } \\\hline 6 & \text { Unexposed } & \text { Exposed } \\\hline 7 & \text { Exposed } & \text { Exposed } \\\hline 8 & \text { Unexposed } & \text { Unexposed } \\\hline 9 & \text { Exposed } & \text { Unexposed } \\\hline 10 & \text { Unexposed } & \text { Unexposed } \\\hline 11 & \text { Exposed } & \text { Exposed } \\\hline 12 & \text { Unexposed } & \text { Exposed } \\\hline 13 & \text { Exposed } & \text { Unexposed } \\\hline 14 & \text { Enposed } & \text { Unexposed } \\\hline 15 & \text { Unexposed} & \text { Unexposed } \\\hline\end{array}$$

A) 0.50
B) 0.67
C) 1.00
D) 2.00
E) 2.25

Question 7

Epidemiologists decided to investigate the effect of sunscreens on sunburns.They ran an epidemiologic study to see the association of sunscreens and sunburns.Overall,460 people have enrolled in the study.Investigators randomly allocated 230 people to the treatment group (sunscreens) and 230 to the control group (placebo).They exposed those 460 people to the high mountain trail on a sunny day.At the end of the study,30 people developed sunburns in the sunscreen group and 130 people developed sunburns in the placebo group.What is the risk of developing sunburns in the placebo group?

A) 0.13
B) 0.15
C) 0.23
D) 0.57
E) 1

Question 8

The following information summarizes the exercise status and obesity status in a case-control study.What is the odds ratio of regular exercise in this study? Use the following table to answer the question. Exercise Status by Obesity Status

A) 0.16
B) 0.26
C) 0.37
D) 0.44
E) 0.59

Question 9

What is the estimated odds ratio of cases when analyzing this study as a matched case-control study design? Use the information from a case-control study table. Exposure Status by Disease Status

A) 0.50
B) 0.67
C) 1.00
D) 2.00
E) 2.25

Question 10

Consider the following 2 × 2 table from a hypothetical cohort study.Calculate the relative risk of CVD comparing those with high fasting glucose (≥126 mg/dL) with those with normal fasting glucose (<126 mg/dL)

A) 0.33
B) 0.75
C) 1.02
D) 3.08
E) 5.34

Question 11

Epidemiologists decided to investigate the effect of sunscreens on sunburns.They ran an epidemiologic study to see the association of sunscreens and sunburns.Overall,460 people have enrolled in the study.Investigators randomly allocated 230 people to the treatment group (sunscreens) and 230 to the control group (placebo).They exposed those 460 people to the high mountain trail on a sunny day.At the end of the study,30 people developed sunburns in the sunscreen group and 130 people developed sunburns in the placebo group.What is the relative risk of sunburns in the sunscreen treatment group compared with the control group in this study?

A) 0.12
B) 0.13
C) 0.23
D) 1.33
E) 4.33

Question 12

Consider the following 2 × 2 table from a hypothetical cohort study.Calculate the incidence of cardiovascular disease (CVD) among the not exposed participants.

A) 9 per 100 population
B) 28 per 100 population
C) 44 per 100 population
D) 50 per 175 population
E) 72 per 100 population