experimental design

Question 1

issues in causal research

Answer 1

1. bias
2. random error
3. confounding
4. effect modification

Question 2

bias

Answer 2

differential error: usually produces deviation/distortion in one direction

Question 3

random error

Answer 3

less likely to distort/ influence the direction of the relationship. it decreases the probability of finding a real association by reducing the statistical power

Question 4

confounding

Answer 4

a measure of the effect of exposure on risk is distorted bc of the association of exposure with other factors that influence the outcome

Question 5

effect modification

Answer 5

differences in the effects of one or more factors according to the level of remaining factors

Question 6

quantitative designs

Answer 6

1. observational: no intervention or experiment
2. experimental: manipulation of study factors

Question 7

observational designs

Answer 7

1. cross-sectional
2. longitudinal

Question 8

cross-sectional

Answer 8

one set of observations is collected from every unit in the study, at a certain point in time

Question 9

longitudinal

Answer 9

2 or more sets of observations are collected for every unit in the study

Question 10

cohort studies

Answer 10

tracks people forwatd in time from exposure to outcome

Question 11

effect measure for cohort studies

Answer 11

risk ration

Question 12

case-control studies

Answer 12

2 source populations: track studies backwards from outcome to exposure

Question 13

when is it best to use RR

Answer 13

1. observational
2. prospective
3. longitudinal

Question 14

when is it best to use OR

Answer 14

1. observational
2. longitudinal
3. retrospective

Question 15

experimental study

Answer 15

a trial that is experiencing the effectiveness and the risks of any medical treatment

Question 16

advantages of randomized clinical trial

Answer 16

1. best evidence study design
2. no inclusion bias
3. controlling for possible confounders
4. comparable groups

Question 17

disadvantages of randomized clinical trial

Answer 17

1. large trials
2. long-term follow up
3. compliance
4. expensive

Question 18

preclinical trial

Answer 18

models in vitro or in vivo

Question 19

phase 0

Answer 19

human studies with minimal doses and are designed to accelerate the development of promising drugs

Question 20

phase I:

Answer 20

first stage of testing in human subjects; how much drug can be administered without causing serious adverse effects: healthy volunteers

-dose escalation

Question 21

phase II:

Answer 21

the drug is administered to a greater number of individuals, suffering from diseases: establishes the minimum effective dose in humans and the optimal dose regimen and any side effects

Question 22

phase III:

Answer 22

the drug is administered to a large number of subjects: randomized controlled multicenter studies

Question 23

Phase IV:

Answer 23

studies are conducted after the marketing of the product under investigation

Question 24

noncompliance

Answer 24

patients may agree to be randomised but following randomisation do not adhere with the assigned treatment