12 - Key approaches

Question 1

The Canadian Health Measure Survey aims to collect important health information through __________________________________

Answer 1

interview, blood and urine

Question 2

The CHMS is led by (3):

Answer 2

• Statistics Canada
• Health Canada
• Public Heath Agency of Canada

Question 3

US NHANES is led by:

Answer 3

the National Center for Health Statistics

Question 4

Researcher intervenes to change exposure then observes/measures what happens (cause-effect): _____________________

Answer 4

Experimental studies

Question 5

Researcher observes/measures exposure and outcome (does not manipulate) , environment is not changed, not a true experiment, associations not causations:_______________________

Answer 5

Observational studies

Question 6

Groups are being compared, aims to associate exposure/intervention and outcome: _________________

Answer 6

Analytical studies

Question 7

Help identify patterns and generate hypothesis, case report, surveys, fact-finding inquiries, frequency and distribution of single variables:

Answer 7

Descriptive study

Question 8

Explain case reports:

Answer 8

• They are an in-depth analysis of a single individual, unit or event
• Direct observation and questioning
• Provides considerable detail
• Usually concern rare events

Question 9

What are 3 challenges associated with case reports?

Answer 9

• Difficult to draw clear causal linkages
• Generalizability of findings
• Potential for observer bias

Question 10

What are the 3 types of analytical studies?

Answer 10

1) Cohort (prospective)
2) Case-control
3) Cross-sectional

Question 11

• Characterize (observe) exposures in participants and then track them overtime
• Compared exposed vs controls =

Answer 11

Cohort (prospective)

Question 12

• Enroll participants with disease or outcome and find matched controls
• Compare previous exposures between groups =

Answer 12

Case-control

Question 13

• Enroll participants and measure exposures and health simultaneously
• Snapshot =

Answer 13

Cross-sectional

Question 14

What study is an example of a cohort study?

Answer 14

Nurses Health Study

Question 15

What are the pros of a cohort study (3):

Answer 15

• can match subjects at baseline
• establish timing of events
• can standardize exposures

Question 16

What are the cons of a cohort study (4):

Answer 16

• associative study (not causal)
• blinding is difficult
• not randomized
• rare diseases need large sample size and long follow-up

Question 17

What study is the opposite of a cohort study:

Answer 17

CASE-CONTROL STUDY

Question 18

Start with an outcome/disease and then work backwards to identify possible causes:

Answer 18

case-control study

Question 19

What are the pros of a case-control study (3):

Answer 19

• Relatively quick and cheap
• Most feasible for rare disorders or outcomes with long latency period
• Fewer subjects needed than other studies

Question 20

What are the cons of a case-control study (5):

Answer 20

• Associative study (not causal)
• Reliance on recall and records to determine exposures (past diet??)
• Not randomized
• Control groups hard to find
• Selection bias

Question 21

Study at one point in time to determine if there’s an association between exposure and health:

Answer 21

Cross-sectional study

Question 22

What are the pros of a cross-sectional study :

Answer 22

Relatively cheap and simple

Question 23

What are the cons of a cross-sectional study :

Answer 23

• Associative study (not causal)
• Recall bias problems
• Confounders may be unequally distributed

Question 24

What tool can you use to make sure you’re doing an observational study the right way?

Answer 24

The STROBE Checklist

Question 25

What does STROBE stands for:

Answer 25

Strengthening the reporting of Observational studies in Epidemiology

Question 26

T or F: incomplete and inadequate reporting of research hampers the assessment of the strengths and weaknesses of the studies reported in the medical literature. Readers need to know what was done (and what was not), what was done, what was found, and what the results mean. Recommendations on the reporting of studies that are endorsed by leading medical journals can improve the quality of reporting

Answer 26

T

Question 27

What are the 2 sub-studies under experimental studies:

Answer 27

1) Randomized controlled trial (where there’s random allocation)
2) Non-randomized controlled trial

Question 28

Ex: Vaccines for COVID-19, blind the population and blind the researcher so no one knows what is tested where (1/2 are getting the vaccine and the other 1/2 are not getting anything). This is an example of a ________________-

Answer 28

Randomized clinical trial (RCT)

Question 29

What checklist do we use to check what information to include when reporting a randomized trial:

Answer 29

The CONSORT

Question 30

What does CONSORT stand for:

Answer 30

Consolidated Standards of Reporting Trials

Question 31

T or F: Consort is a 25-point checklist, is evidence-based, there’s a minimum set of recommendations for reporting randomized trial

Answer 31

T

Question 32

Explain the Consort flow chart:

Answer 32

1) Enrollment (assessed for eligibility)
2) Allocation (received the allocated intervention)
3) Follow-up (discontinued intervention/give reasons)
4) Analysis (excluded from analysis/give reasons)

Question 33

Collects all studies on a topic and statistically combines results:

Answer 33

Systematic review and meta-analyses

Question 34

What are the 3 type of studies that yield the strongest evidence on the evidence pyramid:

Answer 34

1) Meta-analysis
2) Systematic review
3) Randomized control trial

Question 35

Bradford Hill Criteria for ___________:

Answer 35

Causation

• strength (effect size)
• consistency (is it reproducible?)
• specificity (specific population, specific site)
• temporality (cause and then effect
• biological gradient (greater exposure = greater incidence
• plausibility - a believable mechanism linking
• coherence - epid and lab studies
• experiment