Final - Wk 9 (observational studies) Flashcards Preview

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Flashcards in Final - Wk 9 (observational studies) Deck (36)
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1

True/False:
-- P-values can tell you if the mean difference b/w groups in a study is statistically significant and if there is bias present????

false

2

Which type of study would be the best to assess associations in a rare disease?

case control

3

Observational vs Experimental:
-- Which study design category do investigators have control of variables?

experimental

4

Observational vs Experimental:
-- Which study design category do investigators not have control of variables?

observational

5

Observational vs Experimental:
-- Which study design category is best to use if there are many unknown factors?

observational

6

Observational vs Experimental:
-- Which study design category is best for investigating effect of single factors?

experimental

7

Observational vs Experimental:
-- Which study design category is often the preferred design for studies of adverse events.

observational

8

Descriptive vs Interferential:
-- Which type of analysis is useful mainly for prevalence and incidence - to characterize the population?

descriptive

9

Descriptive vs Interferential:
-- Which type of analysis is useful for any studies looking at cause and effect or associations among risk factors (like OR and RR)?

interferential

10

Descriptive vs Interferential:
-- Which type of analysis cannot test a hypothesis?

descriptive

11

Descriptive vs Interferential:
-- Which type of analysis is used in testing hypotheses?

interferential

12

Cohort studies start with ____ and follow group over time to determine ____.

-- exposure/risk factor
-- outcome

13

What are the 2 outcome measures of cohort studies?

relative risk or risk ratio

14

How do you interpret a relative risk ratio of:
-- PR > 1

increased risk of outcome

15

How do you interpret a relative risk ratio of:
-- PR = 1

No risk of outcome

16

How do you interpret a relative risk ratio of:
-- PR < 1

Reduced risk of outcome

17

What is the correct interpretation of a RR of 1.36?

RRR = [ 1 - RR (1.36) ] x 100

-- so RRR = risk of disease is increased by 36%

18

What is the interpretation of a RR of 0.80?

RRR = [1 - 0.8] = 0.2 x 100 = 20%

-- Risk of the outcome in the exposed group was reduced by 20% (or occurred 20% less) relative to the unexposed group

19

What is the interpretation of a RR of 3.3?

RRR = [1 - 3.3] = 2.3 x 100 230%

-- Outcome was 230% more likely to occur in the exposed group

20

What type of cohort study is this:
-- Cohort with/without risk factor of interest followed forward in time to record outcome?

Prospective

21

What type of cohort study is this:
-- Cohort is followed backward in time to examine risk factors present years in the past?

Retrospective

22

What are 3 advantages of cohort studies?

-- show the natural course of a disease or condition
-- show how Tx work in "real world" settings
-- less possibility for bias

23

What are 2 limitations of cohort studies?

-- expensive
-- cannot prove cause and effect as well as experimental designs like RCT

24

Which is able to suggest cause and effect than case-control or cross-sectional studies:
-- Case-control OR cross-sectional study OR cohort study

cohort study

25

Case-control studies look at the difference between group ____ the disease/condition and one group ____.

-- with
-- without

26

Case-control studies are useful for what type of conditions?

rare conditions

27

Can case-control studies use what types of statistics?

odds ratio

28

How many times more likely the odds of finding an exposure in someone w/ disease is compared to finding the exposure in someone w/o the disease.

odds ratio

29

What does an Odds Ratio > 1 indicate?

OR > 1 = increased frequency of exposure

30

What does an Odds Ratio = 1 indicate?

OR = 1 no change in frequency of exposure