Workshop: Design a Case-Control StudySuppose that you have been hired by the BU student health services department to design a case-control study to assess the following hypothesis among MPH students at BUSPH: Irregular sleep patterns increase the risk of headaches. Be sure that your design addresses the following elements:1. Refine the study hypothesis so that it is as specific as possible and contains all elements of a “good” hypothesis.2. How will you identify and define the cases?o Are there any exclusion criteria that you would apply? 3. How will you sample from the underlying population for your “controls”? o Who will you select as controls?o How will you select them?4. How will you define the exposure of interest?o How will you collect the information on exposure? 5. What other information do you want to know about participants that may be related to the exposure of interest and/or the outcome (potential confounders)? Of these, what will you be able to collect and what will you be unable to collect?6. Which measures of disease frequency and association will you calculate?7. What are the strengths and limitations of your study? o Which limitations could be removed by using a different study design? 8. What other information would you like to know to design this study?
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Introduction:
A case-control study is an observational research design used to identify and evaluate factors that may contribute to a health outcome. In this assignment, we will design a case-control study to assess the hypothesis that irregular sleep patterns increase the risk of headaches among MPH students at BUSPH. We will address the essential elements of study design and consider the strengths and limitations of this approach.
1. Refine the study hypothesis so that it is as specific as possible and contains all elements of a “good” hypothesis.
The study hypothesis should be refined to state that “MPH students at BUSPH who have irregular sleep patterns have a higher risk of developing headaches compared to MPH students at BUSPH who have regular sleep patterns.” This hypothesis is specific, testable, and contains all elements of a “good” hypothesis.
2. How will you identify and define the cases?
Cases will be identified through self-report or medical records of MPH students who have been diagnosed with headaches. Cases will include students who have experienced headaches within the past month and have at least two episodes per week. Students who have a history of migraines or other chronic headaches will be excluded from the study.
3. How will you sample from the underlying population for your “controls”?
Controls will be selected from the same population as cases. They will be MPH students who do not have a history of headaches and have consistent sleep patterns. Controls will be selected through random sampling from the same population as cases.
4. How will you define the exposure of interest?
The exposure of interest is irregular sleep patterns. Irregular sleep patterns will be defined as having variances of at least one hour in the duration of time slept and at least three nights a week.
Information on exposure will be collected through the use of a sleep diary, which will be filled out by students daily for 28 days. The sleep diary will contain information on the duration, quality, and regularity of sleep.
5. What other information do you want to know about participants that may be related to the exposure of interest and/or the outcome (potential confounders)? Of these, what will you be able to collect and what will you be unable to collect?
Information on potential confounders such as age, gender, caffeine intake, medication use, and stress levels will be collected through self-report questionnaires. Information on underlying health conditions such as depression, anxiety, or other chronic diseases will also be collected.
It may be difficult to collect information on some potential confounders, such as stress levels or medication use, as these may not be easily measured or self-reported accurately.
6. Which measures of disease frequency and association will you calculate?
Disease frequency will be measured using incidence proportions, which will be calculated as the number of new cases over the study period divided by the total number of students in the population. The association between irregular sleep patterns and headaches will be measured using odds ratios, which will be calculated as the ratio of the odds of having irregular sleep patterns among cases compared to controls.
7. What are the strengths and limitations of your study? Which limitations could be removed by using a different study design?
Strengths of this study include the ability to identify a potential risk factor for headaches among a specific population of MPH students. The use of controls from the same population as cases should reduce selection bias.
Limitations of this study include the potential for recall bias as students will be asked to report on their sleep patterns and headache frequency. The study design may also be subject to confounding based on unmeasured or residual factors. Additionally, the temporal relationship between exposure and outcome may not be established.
These limitations may be reduced by using a prospective cohort study design that tracks sleep patterns and headache frequency over time.
8. What other information would you like to know to design this study?
Additional information that would be useful to design this study includes the prevalence of irregular sleep patterns among the population of MPH students and the incidence of headaches among the same population. Information on potential sources of bias or confounding should also be considered.
