Quiz 8: Research Design 2 (Cohort Study)
In a prospective cohort study, when is baseline exposure assessed before participants are followed up to determine if they have the health outcome of interest? A. At the beginning of the study B. At the end of the study C. Both are assessed at the beginning and the end of the study D. All of the above is correct E. None of the above is correct
A. At the beginning of the study
The analytical methods for the following study design are at the individual level EXCEPT: A. Ecologic study B. Case-control study C. Cross-sectional study D. Cohort study
A. Ecologic study
Which of the following is not an advantage of a prospective cohort study? A. It usually cost less than a case-control study B. Precise measurement of exposure is possible C. Incidence rates can be calculated D. Recall bias is minimized compared with a case-control study
A. It usually cost less than a case-control study
A major problem resulting from the lack of randomization in a cohort study is: A. The possibility that a factor that led to the exposure, rather than the exposure itself, might have caused the disease B. The possibility that a greater proportion of people in the study may have been exposed C. The possibility that a smaller proportion of people in the study may have been exposed D. That, without randomization, the study may take longer to carry out E. Planned cross-over is more likely
A. The possibility that a factor that led to the exposure, rather than the exposure itself, might have caused the disease
True or False: can cohort study be used to resolve problem associated with recall bias? A. True B. False
A. True
Researchers are conducting a prospective cohort study of the association between being an office worker who uses a computer daily and carpal tunnel syndrome (a hand/arm nerve condition). A total of 250 exposed and 250 unexposed participants are enrolled and followed for 10 years. A total of 30 exposed and 18 unexposed had the outcome of interest over the follow-up period. What is the risk ratio for developing carpal tunnel syndrome? A. 1.47 B. 1.67 C. 1.80 D. 1.90 E. 1.35
B. 1.67
The incidence of gun violence is compared in two cities, one with relaxed gun laws (A), the other with strict gun laws (B). In the city with relaxed gun laws, there were 50 shootings in a population of 100,000 and in the other city, 10 shootings in a population of 100,000. What is the relative risk of gun violence in the city with relaxed gun laws (A)? A. 4 B. 5 C. 3 D. 2 E. 1
B. 5
In a retrospective study, when is baseline exposure assessed before participants are followed up to determine the health outcome of interest? A. At the beginning of the study B. At some point in the past via historical record C. Both are assessed at the beginning and the end of the study D. Data collection do not need assessment E. All of the above is correct
B. At some point in the past via historical record
The following are the disadvantages of cohort studies EXCEPT A. Lengthy to conduct and are subject to attribution B. Not useful for rare exposures C. Difficult to carry out D. Difficult to use with rare diseases E. Selection bias
B. Not useful for rare exposures
In a cohort study, the advantage of starting by selecting a defined population for study before any of its members become exposed, rather than starting by selecting exposed and non-exposed individuals, is that, A. The study can be completed more rapidly B. A number of outcomes can be studied simultaneously C. A number of exposures can be studied simultaneously D. The study will cause less to carry out E. A & D
C. A number of exposures can be studied simultaneously
Researchers are conducting a prospective cohort study of the association between being an office worker who uses a computer daily and carpal tunnel syndrome (a hand/arm nerve condition). Researchers choose a group of office workers from one company to be their "exposed" group. Which of the following "unexposed or less exposed" comparison groups would be the best choice? A. A group of high school students, who use computers daily B. Another group of office workers at a different company, who do not use computers daily C. Another group of office workers at the same company, who do not use computers daily D. A group of professional golfers, who use their hands/arms intensively for their sport
C. Another group of office workers at the same company, who do not use computers daily
Retrospective Cohort studies are characterized by all of the following EXCEPT? A. The study group are exposed and non-exposed B. Incidence rates may be computed C. The required sample size is smaller than that needed for a prospective cohort study D. The required sample size is similar to that needed for a prospective cohort study E. They are useful for rare exposures
C. The required sample size is smaller than that needed for a prospective cohort study
Given the same criteria in question 16. In the city with relaxed gun laws, there were 50 shootings in a population of 100,000 and in the other city, 10 shootings in a population of 100,000. What is the relative risk of gun violence in the city with strict gun laws (B)? A. 0.40 B. 0.45 C. 0.35 D. 0.20 E. 0.30
D. 0.20
Which of the following is true about cohort study? A. Study design maybe subjected to information bias B. Cohort studies require large sample sizes defined as less than 1 even per 1000 years C. Study design may result to loss to follow up because participants may leave before the completion of the study D. All of the above E. None of the above
D. All of the above
All of the following are true of cohort study EXCEPT: A. Subjects with the outcome of interest at baseline are excluded B. All members of the cohort are at risk of developing the outcome at the beginning of observation C. It can allow the investigator to assess multiple health outcomes from a single exposure D. It is cheap, less labor intensive, and easy to conduct than case-control study E. It can be used directly to measure the risk and rate of a health outcome occurrence over time
D. It is cheap, less labor intensive, and easy to conduct than case-control study
The following is true about cohort studies EXCEPT: A. The design can used for rare exposure B. It is expensive and time consuming C. Cause and effect can be determined D. One can calculate relative incidence associated with exposures via odds ratio E. The design is an observational longitudinal study
D. One can calculate relative incidence associated with exposures via odds ratio
What is temporality? A. Determinant of disease, i.e., Risk factors B. Assume to be biological plausibility C. Temporality is prediction in which anticipatory deductions based on hypothesis are put forward in testable ways D. Temporality is timing of information about cause and effect
D. Temporality is timing of information about cause and effect
In cohort studies of the role of a suspected factor in the etiology of a disease, it is essential that: A. There be equal numbers of persons in both study group B. At the beginning of the study, those with the disease and those without the disease have equal risks of having the factor C. The study group with the factor and the study without the factor be representative of the general population D. The exposed and non-exposed groups under study be similar as possible with regard to possible research bias E. Both B & C
D. The exposed and non-exposed groups under study be similar as possible with regard to possible research bias
Which of the following studies can determine temporality? A. Ecological study B. Case-Control Study C. Cohort study D. Randomized clinical trial E. C & D
E. C & D
In the previous question in which researchers are conducting a prospective cohort study of the association between being an office worker who uses a computer daily and carpal tunnel syndrome (a hand/arm nerve condition). Researchers choose a group of office workers from one company to be their "exposed" group. Who should be excluded from the cohort (not included in the study)? A. Both diseases group and exposure group should be part of the study B. Exposed group should be excluded C. The study design is sufficient as it is D. All of the above is correct E. The researchers should exclude any participants who already have carpal tunnel syndrome at the start of the study
E. The researchers should exclude any participants who already have carpal tunnel syndrome at the start of the study
