CSUN What Are Limitations of Using Cross Sectional Design Research Study Worksheet

Research Project: Design and Analysis of a Research StudyOverview: The purpose of this assignment is to use the material you have learned in class to develop a research
study involving a health topic. In this project, you will use your knowledge about research design to propose a
study that will address a key public health issue. You may work in a group or alone. You (and your fellow
group members) must pick a specific exposure and outcome that interests you and develop a research
hypothesis. Your group will design an appropriate study to test your hypothesis using the epidemiologic
concepts covered in class. You will then analyze mock data and evaluate your findings.
Tasks:
• Each week following lecture, you will complete a specific section of this worksheet.
• Once the worksheet is complete you will receive an excel worksheet with a mock dataset to analyze.
• After analyzing your data you will interpret the data and identify the strengths and limitations of your
study.
• You will then right a research abstract to describe all of your work.
Deliverables: Upon completion of this assignment, you will turn in:
• The worksheet
• A short abstract (no more than 500 words)
Complete the following sections to design your research study. You should be able to complete questions
1-4 after the experimental research lecture. After each subsequent lecture, you can add the evaluation of
the study design we reviewed. After all study designs have been evaluated, choose the design that would
work the best to test your hypothesis.
1. State your hypothesis
Ho: Residential exposure to the radioactive gas radon, age, sex, pre-existing health condition, family
history of lung cancer increases the risk of lung cancer.
HI: Residential exposure to the radioactive gas radon, age, sex, pre-existing health condition, family
history of lung cancer does not increase the risk of lung cancer.
2. Why did you choose this topic (what is its importance or relevance to the field?
Lung cancer is a major cause of death across different age-group in the world. The reason for choosing this
topic is to decipher myths and misconception related to the main causes of lung cancer. The study of lung
cancer is a major field study which enables researchers and scientists to come up with medications for lung
cancer related diseases. This field also tries to offer ways of living for people diagnosed with cancer which offer
them longer years of survival. According to research done by (Hanli & Zhiwei, 2016) lunger cancer is one of
the top causes of cancer that is associated with mortality in the world. The main cause of lung cancer across
different patients is smoking (Pavlovska & Orovchanec, 2008)
3. Study Variables
a. Define your Exposure:
i. What is your exposure of interest?
Family history for cancer related diseases and the exposure of radioactive gas radon are the main interest for
this study and research.
ii. What is your control group (or second exposure for comparison)?
Work environment, racial background will act as the control group for this analysis.
b. Define your outcome
i. What is the outcome you are interested in studying?
Residential exposure to the radioactive gas radon, age, sex, pre-existing health condition, family history of
cancer increases the risk of lung cancer.
ii. What is your case definition?
Does an old-aged male person from a family with lung cancer history and exposed to radioactive gas radon has
a high probability of being diagnosed with cancer.
c. Other variables of interest?
i. Are there any other variables you think are important to consider? (ex: age, sex/gender,
disease severity, etc…)
Other important variables but not included in this research include; Individual’s work environment,
geographical locations, environmental pollution, other hazardous chemicals such as uranium, arsenic and nickel.
4. Evaluate the utility of each of the following study designs in testing your hypothesis?
a. Experimental
i. Would this study design work?
Yes.
ii. What are the benefits of using an experimental design?
Experimental design makes it easier to manipulate either the independent or dependent variable.
Manipulating these variables will help in understanding if there is a correlation or causation between the model
variables. In addition, experimental design can help examine the effect of one variable to other variables in the
model.
iii. What are the limitations of using an experimental design?
Experimental design is subject to human error which may lead to unrealistic results. In addition,
adjusting parameters with the aim of achieving a correlation between the independent and dependent variables
may lead to lack of naturality a weak model.
b. Cohort
i. Would this study design work?
No.
ii. Would use a prospective or retrospective design? Why?
Retrospective design. This is because this design studies the patients diagnosed with and without this
disease and tries to see if both groups’ diseases were caused by variables included in the model. Additively,
retrospective design helps in formulating hypothesis for the model with the aim of identifying effect of
dependent variables to the independent variables.
iii. What are the benefits of using a cohort design?
Cohort design makes it easy to identify the exposure of different variables to the overall model study
question. For example, using cohort design in this model it is easier to study the effect each independent
variable to the dependent variable. Cohort design is also an easy and efficient design of studying exposure
caused as a result of changing one or more variables within the model.
iv. What are the limitations of using a cohort design?
It is difficult to use cohort design in determining causality between independent and dependent
variables. Also, the use of cohort design is time consuming and may need a big population which may be
difficult for most researchers.
c. Case Control
i. Would this study design work?
Yes.
ii. What are the benefits of using a case-control design?
Unlike Cohort design, case-control is a good design for accessing the several exposures of rare diseases
for small sample. Possible outcomes can be studied using case-control while calculating response ratio.
iii. What are the limitations of using a case-control design?
The use of case-control design makes it difficult to accurately estimate the incidence of diseases as a result of
selection bias. Additively, unlike retrospective design, case-control requires the researcher to know the outcome
of the exposure before the study begins.
d. Cross Sectional
i. Would this study design work?
No.
ii. What are the benefits of using a cross sectional design?
Cross sectional design makes it easier to compare the effect of different independent variables on the
dependent variables. That is, the effect of age, exposure to radon, pre-existing health as a cause of lung cancer
to an individual. In addition, it is cost and time-effective to use cross sectional design because data is collected
at a point of view. For example, in this study data related to age, sex, radioactive exposure can be collected
collectively at given point of view.
iii. What are the limitations of using a cross sectional design?
It is difficult to determine the correlation and causation between exposure and outcome since all the
variables are analyzed with the same time. Temporal relationship becomes more difficult while using cross
sectional design because data used by this design focusses on prevalent cases and not incident cases.
5. Which of these study designs would you select to conduct your study in the real world?
Experimental design work. Compared to the other 3 designs, design work is the most effective method
which can be used in the real world.
6. Do you need IRB approval for your study? ___Yes
____No
Yes
Why? I consider this study as professional research which includes human related subjects. This
is because such information requires the approval of the board to avoid misinformation. For example,
the IRB will ensure that the research complies with the necessary and applicable regulations.
7. Do you need a Data Safety Monitoring Board for your study? ___Yes
Why?
Yes.
____No
Data Safety Monitoring Board requires all researchers to comply with regulations related to the
collection of data. This study will include studying group’s pre-existing health conditions. Data Safety
Monitoring Board will monitor the trial to ensure safety and standard is upheld.
8. Define your population:
a. Who will you study?
Individuals aged between 45-90 years, workers especially those working in areas with high exposure of
radioactive gas radon. People living around industries will also be studied.
b. Who will you exclude from you study?
Individuals with other cancer related diseases apart from lung cancer will be excluded. This is because, a
population with other forms of cancer will be complicate the study model.
9. Enrollment:
a. How many people will you study?
20. This is a possible study group which will be less time consuming and will create a few errors. Few
errors replicate more accurate outcomes.
b. Describe how you will enroll your subjects into your study:
The model will use one dependent variable and 4 independent variables. The following will be the
independent variables; Residential exposure to the radioactive gas radon, age, sex, pre-existing health condition,
family history of lung cancer increases the risk of lung cancer.
10. Study Design Tools:
a. What tools would you use to strengthen your study (make sure they are appropriate for the
study design you selected):
i. Randomization;
ii. Random allocation ((choose this one)
iii. Restriction ((choose this one))
iv. Stratification
v. Matching
vi. Blinding
vii. Double Blinding
Random allocation and Restriction
b. Describe how you will use the tools selected above:
Random Allocation;
I will assign every variable a given number from a to d. The dependent variable will be assigned letter Y
while the independent variables will be assigned letter a, b, c, d and e. Residential exposure to the radioactive
gas radon (a), age (b), sex (c), pre-existing health condition (d) , family history of lung cancer increases the risk
of lung cancer (e). After this I would use random number generator tool for randomization.
Congratulations! You have conducted your study. Submit the information above to receive your data. Once
you have data you can proceed to the next page.
11. Results:
a. What calculation will you use to determine the measure of association?
i. Odds Ratio
ii. Prevalence Ratio
iii. Relative Risk ((choose this))
RR = Intervention events/(Intervention events + Intervention non-events)/(Control events/(Control events +
Control non-events)
Or
Risk Ratio = Cle (exposed group)/ Clu (unexposed group)
b. Complete the 2×2 table below with a summary of your data:
Outcome
No Outcome
Exposed
Not Exposed
Total
c. Calculate your measure of association (show your work):
Total
12. Conclusions:
a. Interpret your findings:
b. Circle the guidelines for causality that provide evidence that your results is accurate and
state why:
i. Temporal Relationship:
______________________________________________________
ii. Strength of Association:
_____________________________________________________
iii. Dose-Response Relationship:
_________________________________________________
iv. Replication of Findings:
______________________________________________________
v. Biologic Plausability
vi. Consideration of Alternate Explanations:
________________________________________
vii. Cessation of Exposure:
_______________________________________________________
viii. Specificity of the Association:
__________________________________________________
ix. Consistency with other Knowledge:
______________________________________________
c. List at least 3 limitations that may have effected your study results:
d. What would you change about your study design to improve future research?
13. Draw a flow chart for your study:
References
Pavlovska, I., & Orovchanec, N. (2008). Lung cancer and the smoking habit. Pubmed.gov, 26980. https://pubmed.ncbi.nlm.nih.gov/19259052/
WANG, H., & LU, Z. (2016). A case of primary non-small cell lung cancer with synchronous small cell lung
cancer. Molecular and Clinical Oncology, 5(1), 171-174. https://doi.org/10.3892/mco.2016.859
References
Submit completed worksheet with your summary abstract!
Research Design and Analysis Grading Rubric
Hypothesis
(3 pts)
90-100%
Testable Question with a
clear exposure and outcome
Purpose and
Justification
(10 pts)
Provides clear reasons why
this study is important.
Cites other work as
evidence of knowledge in
the topic area.
Define Exposure
Variable (4 pts)
Selected correct variable as
exposure and split into 2
clear and distinct groups for
comparison
Define Outcome
Variable (4 pts)
Selected correct variable as
outcome and used a clear
and objective case
definition or outcome can
only be measured
subjectively.
Correctly names 3 study
designs that could be used
to test the hypothesis and
at least 1 accurate benefit
and limitation for each
study design
Propose 3 study
designs: (10 pts)
70-89%
Testable Question, but
missing exposure or
outcome
Provides some reasons
why this study is
important. May cite
other work as evidence of
knowledge in the topic
area.
Selected correct variable
as exposure and split into
groups for comparison.
Groups may be vague or
less distinct
Selected correct variable
as outcome and used a
clear and objective case
definition.
=2
study designs that could
be used to test the
hypothesis and at least 1
accurate benefit and
limitation for each study
design
Provides justification for
selection of study design
including benefits or
limitations
IRB (2 pts)
Answered correctly and
justifies with applicable
factors
Answer may not be
correct, but justification is
on the right track
DSMB (2 pts)
Answered correctly and
justifies with applicable
factors
Answer may not be
correct, but justification is
on the right track
Correct answer with little
to no justification
Population
Definition (3 pts)
Enrollment (5 pts)
Clear objective enrollment
criteria
Enrollment strategy is
appropriate for study design
and includes who will be
recruited and classification
into exposure/case groups.
Tools (5 pts)
All tools selected are
appropriate for study design
and clear explanation for
use in study is given.
Clear, but incomplete
enrollment criteria
Enrollment strategy is
appropriate for study
design and includes who
will be recruited or
classification into
exposure/case groups.
Most tools selected are
appropriate for study
design and explanation
for use in study is given.
Vague and incomplete
enrollment criteria
Enrollment strategy is
appropriate for study
design but does not
includes who will be
recruited or classification
into exposure/case groups.
At least 1 tool selected are
appropriate for study
design, but explanation for
use in study is vague or not
given.
Did not answer
Did not answer or
selected wrong
answer with no
justification
Did not answer or
selected wrong
answer with no
justification
Did not answer
Did not answer or
enrollment is
inappropriate for
the study design
Did not answer or
selected all
inappropriate tools
or no explanation.
Results (10 pts)
Conclusions
(10 pts)
Causality
(5 pts)
Limitations
(5 pts)
Study Modifications
(5 pts)
Flow Chart
(2 pts)
Partner Evaluation
(8 pts)
Independent Work
Product (5 pts)
Overall Abstract
Evaluation (50 pts)
4-5
Selected the correct
measure of association and
use the formula to calculate
Interpreted the finding in a
full and complete sentence
stating the difference
between groups to
demonstrate an
understanding of the
meaning of the measure of
association.
Correctly identified and
explained evidence of
causality applying it to
outside literature or
concepts
Correctly identified and
explained possible biases or
other limitations
3
Selected the incorrect
measure of association,
but applied that formula
correctly
Interpreted the finding in
a vague or poorly stated
way, but demonstrated
an understanding of the
meaning of the measure
of association.
1-2
Selected the correct
measure, but did not
correctly perform the
calculation
Attempted, but did not
correctly interpret the
findings.
0
Did not answer
Correctly identified, but
vaguely and explained the
evidence causality
Correctly identified, but
did not explain the
evidence of causality
Did not answer
Correctly identified, but
Correctly identified, but
vaguely and explained the did not explain the
possible biases or other
possible biases or other
limitations
limitations
Identifies at least one
Identifies at least one
Identifies at least one
element of the study design element of the study
element of the study
that could be improved and design that could be
design that could be
clearly explains how this
improved and vaguely
improved but does not
change will enhance the
explains how this change
explain how this change
understanding of the
will enhance the
will enhance the
outcome.
understanding of the
understanding of the
outcome.
outcome.
Flow chart shows the
Flow chart shows most of Flow chart shows some of
correct elements of the
the correct elements of
the correct elements of
study design
the study design
the study design
Partner gives score of
Partner gives score of
Partner gives score of no
meaningful contribution
minimal contribution
contribution
Produced a product that
Produced a product that
Produced a product that
shows independent thinking shows some independent shows minimal
and personal perspective
thinking and personal
independent thinking and
perspective, but has
personal perspective
some overlap with
partners in syntax or
wording
• Contains all required
• Missing some sections
• No section labels,
sections with clear labels
disorganized content.
• Missing relevant
(Intro, Methods, Results,
information
• Many misuses of scientific
Discussion)
terms
• Provides too much
• Provides clear, concise, and
information
• Does not abide by word
relevant summary of
count limitations
• At least 95% Information
research
is in the correct section
• Information is in the
correct section
Did not answer
Did not answer
Did not answer
Did not answer
Produced a
product that shows
lack of personal
thought
Did not complete
abstract
Radioactive Gas Exposure
Lung Cancer
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