Epidemiological study design

Question 1

Type of observational study that:
Often provide info about rare occurrences, can help identify new trends or diseases

Answer 1

Case report/series

Question 2

Type of observational study that:
Examines relationship between exposure and disease with population-level data

Answer 2

Ecological/correlation study

Question 3

Phenomenon where absence of individual cause and effect may lead to faulty associations

Answer 3

Ecological fallacy

Question 4

Type of observational study that:
Examines relationship between exposure and disease prevalence in a defined population at a single point in time (“Snapshot study”)

Answer 4

Cross-sectional (prevalence survey)

Question 5

Type of observational study that:
Compares group with disease to group without disease and looks for prior exposure or risk factor
“What happened?”

Answer 5

Case control (retrospective) studies

Question 6

Type of observational study that:
Exposure information is collected at the start of the study and the new cases of disease are identified
“Watch and wait”
Can measure incidence

Answer 6

Cohort (longitudinal or prospective) studies

Question 7

Observational study that is a “snapshot study”

Answer 7

Cross sectional

Question 8

Observational study that looks at “What happened?”

Answer 8

Case-control studies

Question 9

Observational study that is a “Watch and wait”

Answer 9

Cohort studies

Question 10

Experimental study type that is good if effect is permanent or long-lasting

Answer 10

Randomized controlled studies

Question 11

Experimental study type that is preferred format if effect is of short duration

Answer 11

Crossover studies

Question 12

Subset of selection bias that arises from evaluating data on biased patients and hospital records only (not a good sample of the population)

Answer 12

Berkson bias

Question 13

Berkson bias is a subset of this type of bias

Answer 13

Selection bias
(Arises from evaluating data on biased patients and hospital records only (not a good sample of the population))

Question 14

Loss to follow up is a subset of this type of bias

Answer 14

Selection bias

Question 15

Healthy worker/volunteer is a subset of this type of bias

Answer 15

Selection bias

Question 16

Recall bias is typically associated with this type of study

Answer 16

Case control studies

Question 17

Refers to the fact that some subjects will alter their behavior when they know they are being studied

Answer 17

Hawthorne effect

Question 18

Hawthorne effect is a subset of this type of bias

Answer 18

Measurement (performing bias)
(Refers to the fact that some subjects will alter their behavior when they know they are being studied)

Question 19

Subset of performing bias where participants in different groups are not treated the same

Answer 19

Procedure bias

Question 20

Subset of performing bias where the researcher inadvertently conveys his expectations regarding his expectation of the result (“self-fulfilling prophecy”)

Answer 20

Observer-expectancy bias (Pygmalion effect)

Question 21

Recall bias, Measurement, Procedure bias, and Observer-expectancy bias are subsets of this type of bias

Answer 21

Performing bias

Question 22

Subset of interpreting results bias where association between exposure and outcome is distorted by an extraneous third variable

Answer 22

Confounding

Question 23

Subset of interpreting results bias where early detection looks like an increase in survival

Answer 23

Lead-time

Question 24

Subset of interpreting results bias where screening test identifies disproportionate number of slowly progressing diseases but misses rapidly progressing diseases

Answer 24

Length

Question 25

Study design at the top of the evidence pyramid where multiple studies summarized with selection based on predetermined criteria

Answer 25

Systematic review

Question 26

Study design at the top of the evidence pyramid that pools data from several studies using statistical analysis to estimate treatment effect

Answer 26

Meta-analysis

Question 27

Observational studies used when there is no comparison group available

Answer 27

Case report/series and ecological/correlational design

Question 28

Observational study where exposure is known, and outcome is studied

Answer 28

Cohort study

Question 29

Observational study where outcome is known, and exposure is studied

Answer 29

Case-control

Question 30

Observational study where exposure and outcome are known

Answer 30

Cross-sectional