Description
this is an epidemiology course in public health . see attach questions
QUESTION 1
1.
A cohort study was undertaken to examine the
association between high lipid level and coronary
heart disease (CHD). Participants were classified as
having either a high lipid level (exposed) or a low or
normal lipid level (unexposed). Because age is
associated with both lipid level and risk of heart
disease, age was considered a potential confounder or
effect modifier and the age of each subject was
recorded. The following data describes the study
participants: Overall, there were 11,000 young
participants and 9,000 old participants. Of the 4,000
young participants with high lipid levels, 20 of them
developed CHD. Of the 6,000 old participants with
high lipid levels, 200 of them developed CHD. In the
unexposed, 18 young and 65 old participants
developed CHD.
o
o
o
o
QUESTION 2
1.
Construct the appropriate two by two tables
using the data given above. Be sure to label the
cells and margins.
Calculate the appropriate crude ratio measure
of association combining the data for young
and old individuals.
Now, perform a stratified analysis and calculate
the appropriate stratum-specific ratio measures
of association. What are they?
Do the data provide evidence of effect measure
modification on the ratio scale? Justify your
answer
A study used self-administered mail questionnaires to
gather data on height and weight in order to calculate
a measure of obesity. Which of the following types of
problems were likely avoided by this method of data
collection, and why?
o
o
o
o
o
Interviewer bias
Exposure misclassification
Confounding
Selection bias
Loss-to-follow-up
QUESTION 3
1.
The association between cellular telephone use and
the risk of brain cancer was investigated in a casecontrol study. The study included 475 cases and 400
controls and the following results were seen:
Cellular Yes
Phone
No
User
Total
Cases
270
Controls
200
205
200
475
400
o
o
Calculate the odds ratio based on these data.
The p value for this odds ratio is 0.06. State
your interpretation of this p-value.
Gender was considered a potential confounder and
effect measure modifier in this study. The data were
stratified into males and females in order to assess
these issues.
Males
Cellular Yes
Phone
No
User
Cases
242
Controls
150
Females
Cases
Yes 28
100
50
No
o
105
Controls
50
150
Calculate the stratum-specific odds ratios.
o
o
Is gender a confounder in this study? Briefly
justify your answer.
Is gender an effect measure modifier in this
study? Briefly justify your answer
Purchase answer to see full
attachment
1.
A cohort study was undertaken to examine the
association between high lipid level and coronary
heart disease (CHD). Participants were classified as
having either a high lipid level (exposed) or a low or
normal lipid level (unexposed). Because age is
associated with both lipid level and risk of heart
disease, age was considered a potential confounder or
effect modifier and the age of each subject was
recorded. The following data describes the study
participants: Overall, there were 11,000 young
participants and 9,000 old participants. Of the 4,000
young participants with high lipid levels, 20 of them
developed CHD. Of the 6,000 old participants with
high lipid levels, 200 of them developed CHD. In the
unexposed, 18 young and 65 old participants
developed CHD.
o
o
o
o
QUESTION 2
1.
Construct the appropriate two by two tables
using the data given above. Be sure to label the
cells and margins.
Calculate the appropriate crude ratio measure
of association combining the data for young
and old individuals.
Now, perform a stratified analysis and calculate
the appropriate stratum-specific ratio measures
of association. What are they?
Do the data provide evidence of effect measure
modification on the ratio scale? Justify your
answer
A study used self-administered mail questionnaires to
gather data on height and weight in order to calculate
a measure of obesity. Which of the following types of
problems were likely avoided by this method of data
collection, and why?
o
o
o
o
o
Interviewer bias
Exposure misclassification
Confounding
Selection bias
Loss-to-follow-up
QUESTION 3
1.
The association between cellular telephone use and
the risk of brain cancer was investigated in a casecontrol study. The study included 475 cases and 400
controls and the following results were seen:
Cellular Yes
Phone
No
User
Total
Cases
270
Controls
200
205
200
475
400
o
o
Calculate the odds ratio based on these data.
The p value for this odds ratio is 0.06. State
your interpretation of this p-value.
Gender was considered a potential confounder and
effect measure modifier in this study. The data were
stratified into males and females in order to assess
these issues.
Males
Cellular Yes
Phone
No
User
Cases
242
Controls
150
Females
Cases
Yes 28
100
50
No
o
105
Controls
50
150
Calculate the stratum-specific odds ratios.
o
o
Is gender a confounder in this study? Briefly
justify your answer.
Is gender an effect measure modifier in this
study? Briefly justify your answer
Purchase answer to see full
attachment
Categories: