Deck 8: Cohort Studies

Question 1

Cumulative incidence or average risk is typically used as the measure of disease frequency with which type of cohort because there are no losses to follow-up?

A) Open cohort
B) Fixed cohort
C) Closed cohort
D) Dynamic cohort

Answer 1

Closed cohort

Question 2

Which of the following are used in experimental studies to match as closely as possible the experiences of the experimental and comparison groups to permit masking of study investigators?

A) Placebos
B) Variables
C) Confounders
D) Protocols

Answer 2

Placebos

Question 3

A special cohort would be assembled to examine the effects of which of the following?

A) Oral contraceptives
B) Medical procedures
C) Cigarette smoking
D) Alcohol consumption

Answer 3

Medical procedures

Question 4

Although there are several advantages to using the general population as a comparison group, which of the following is the main disadvantage?

A) Confounding
B) Selection bias
C) Counterfactual ideal
D) Healthy worker effect

Question 5

A comparison group consisting of exactly the same individuals as those in the exposed group had they not been exposed is an example of which theoretical concept?

A) Confounding
B) Selection bias
C) Counterfactual ideal
D) Healthy worker effect

Question 6

Calculating which measure involves determining the amount of person-time accrued by each study subject?

A) Incidence rate
B) Prevalence rate
C) Morbidity rate
D) Mortality rate

Question 7

All of the information in a proportional mortality ratio (PMR) study comes from which source?

A) Medical records
B) Biomarkers
C) Death certificates
D) Physical examinations

Question 8

Observational studies take advantage of the fact that people expose themselves to noxious or healthy substances through their personal habits.

Question 9

In an ambidirectional cohort study, both the exposures and outcomes have already occurred by the time the study begins.

Question 10

Prospective cohort studies are more efficient than retrospective studies for investigating diseases that take a long time to develop and come to a diagnosis.

Question 11

Exposures in which type of cohort do not change over time and are followed from a defined starting point to a defined ending point but may suffer from losses to follow-up?

A) Open cohort
B) Fixed cohort
C) Closed cohort
D) Dynamic cohort

Question 12

Which of the following is the appropriate measure of disease frequency in a fixed cohort when the population experiences losses to follow-up?

A) Incidence rates
B) Prevalence rates
C) Mortality rates
D) Cumulative incidence rates

Question 13

Which of the following is assembled to study the health effects of rare exposures, such as uncommon occupational chemicals?

A) Open cohort
B) Fixed cohort
C) Special cohort
D) General cohort

Question 14

Which of the following is often selected from professional groups such as doctors and nurses, volunteers, or residents in well-defined geographic areas to facilitate follow-up and accurate ascertainment of the outcomes under study?

A) Open cohort
B) Fixed cohort
C) Special cohort
D) General cohort

Question 15

Which type of comparison group is commonly used in occupational studies of mortality because these data are quite accessible to researchers?

A) General population
B) Internal comparison group
C) External comparison group
D) Comparison cohort

Question 16

Epidemiologists have found that which type of comparison group is the best type of comparison group to use in a cohort study?

A) General population
B) Internal comparison group
C) External comparison group
D) Comparison cohort

Question 17

If lost individuals are more or less likely to be exposed than those successfully traced, the study results may suffer from which of the following?

A) Confounding
B) Selection bias
C) Counterfactual ideal
D) Information bias

Question 18

Observational studies are considered "natural" experiments because the investigator acts as a disinterested observer, merely letting nature take its course.

Question 19

The timing of prospective cohort studies is similar to that of experimental studies?

Question 20

Investigators in a retrospective cohort study can usually obtain more detailed information on exposures and other key variables because they have more control of the data collection process and can gather information directly from the participants.