Instruction:
I. Describe the type of study design that is most appropriate for each scenario and why
1.Outbreak of gastroenteritis has occurred among 80 attendees of a conference at Tourist Hotel. You have been asked to investigate this outbreak and identify the source, if possible. All of the attendees will remain at the hotel for 4 more days, so you can ask everyone to fill out a questionnaire about what they ate and drank.
2.One report presents four cases of human fascioliasis in Ethiopia. There are only few case reports of human fascioliasis in Ethiopia as the disease mostly affects animals. However, the need to be aware of the possibility of occurrence of this disease in humans and the inclusion of drugs used for treating the disease, in the Ethiopian drug list, should be emphasized.
3.The surveillance system has identified 23 confirmed cases of hepatitis A in a large community. Usually the community has only 1 or 2 cases in the same time period. The cases appear to live in different parts of the city. You have been asked to investigate this increase and identify the cause, if possible.
4.Investigators examine data from police records to identify crash factors associated with a driver fatality vs.driver non-fatality. The crash factors they consider are driver blood alcohol level, driver age and driver use of the seat belt
5.Researchers administered a questionnaire to all new students at paramed college. The questionnaire included questions about behaviors such as exercise, smoking, and alcohol consumption. The researchers plan to distribute follow-up questionnaires at graduation and every five years thereafter, asking about health events and conditions such as diabetes and heart disease.
6.To investigate the relationship between egg consumption and heart disease, a group of patients admitted to a hospital with myocardial infarction were questioned about their egg consumption. Another group of patients admitted to a fracture clinic were also questioned about the egg consumption using an identical protocol.
7.To test the efficacy of vitamin C in preventing colds, students are randomly assigned to two groups: one given 500mg of vitamin C daily, and one given placebo. Both groups are followed to determine the number and severity of subsequent colds.
8.To investigate the relationship between certain solvents and cancer, all employees at a factory were questioned about their exposure to an industrial solvent, and the amount and length of exposure measured. These subjects were regularly monitored, and after 10 years a copy of the death certificate for all those who died was obtained.
9.A survey was conducted of all the physicians employed at a particular hospital. Among other questions, the questionnaire asked about the number of years in study and whether or not she/he was satisfied with her career prospects.
10.A study describes the clinical course of patients who have very rare neurological disorder. Patients are identified at a referral center that specializes in this disease. Their medical records are reviewed for patient characteristics and treatments and are then related to their current status.
1. The most appropriate study design for this scenario would be a cross-sectional study. By distributing a questionnaire to all attendees of the conference at the Tourist Hotel, the researchers can gather information about what they ate and drank, which can help identify the source of the outbreak. This study design allows for the collection of data at a single point in time, providing a snapshot of the situation.
2. A case report or case series would be the most appropriate study design for this scenario. Since there are only a few cases of human fascioliasis in Ethiopia and the disease mostly affects animals, it is not feasible to conduct a larger study. The case report(s) can provide valuable information about the occurrence of the disease in humans and help raise awareness.
3. The most appropriate study design for this scenario would be a descriptive epidemiological study. By investigating the increase in hepatitis A cases in the large community and identifying the different parts of the city where the cases live, researchers can gather data to describe the distribution and characteristics of the outbreak. This study design allows for the identification of patterns and potential causes of the increase in cases.
4. A case-control study would be the most appropriate study design for this scenario. By examining data from police records, researchers can compare crash factors associated with a driver fatality vs. driver non-fatality. This study design allows for the identification of potential risk factors for driver fatalities.
5. This scenario describes a cohort study design. By administering a questionnaire to all new students at paramed college and planning to distribute follow-up questionnaires at graduation and every five years thereafter, researchers can gather longitudinal data to study the relationship between behaviors such as exercise, smoking, and alcohol consumption, and health events and conditions such as diabetes and heart disease.
6. This scenario also describes a case-control study design. By questioning a group of patients admitted to a hospital with myocardial infarction and a group of patients admitted to a fracture clinic about their egg consumption, researchers can investigate the relationship between egg consumption and heart disease. This study design allows for the comparison of cases (patients with myocardial infarction) and controls (patients without myocardial infarction).
7. This scenario describes a randomized controlled trial (RCT) design. By randomly assigning students to two groups (one receiving vitamin C and one receiving placebo) and following them to determine the number and severity of subsequent colds, researchers can test the efficacy of vitamin C in preventing colds. This study design allows for the control of confounding variables and the determination of causality.
8. The most appropriate study design for this scenario would be a cohort study. By questioning all employees at a factory about their exposure to an industrial solvent, measuring the amount and length of exposure, and regularly monitoring them, researchers can investigate the relationship between certain solvents and cancer. This study design allows for the identification of potential risk factors and the collection of longitudinal data.
9. This scenario describes a cross-sectional study design. By conducting a survey of all physicians employed at a particular hospital and asking about the number of years in study and career prospects, researchers can gather data at a specific point in time to describe the characteristics and satisfaction levels of the physicians.
10. The most appropriate study design for this scenario would be a retrospective cohort study. By identifying patients at a referral center specializing in the rare neurological disorder and reviewing their medical records for patient characteristics, treatments, and current status, researchers can investigate the clinical course of the disease. This study design allows for the collection of historical data and the examination of outcomes based on exposure.