Selection, comparability, confounding

Question 1

Inclusion criteria

Answer 1

-creat homogenous group likely to respond to intervention
-consider who would use this medication in practice
-some stuies of adhearance

Question 2

exclusion criteria

Answer 2

-meant to ensure safety when therapy may be harmful
-exclude subjects who have inconsistent result
-may be budget considerations

Question 3

Determine comparability between intervention and control groups

Question 4

Identify confounding variables

Question 5

how may a confounding variable influence a study result

Question 6

Study samples

Answer 6

-seek a representative sample of applicable population
-recruit, don’t use volunteers
-criteria established a priori to best represent a population

Question 7

True or False: You should be cautious of elimination due to investigator discretion, or ‘other’ reasons

Answer 7

True, investigator discretion may be different between people

Question 8

Homogeneous sample desires

Answer 8

-less variability
-higher likelihood of statistically significant effect: demontration of EFFICACY
-less able to generalize

Question 9

Heterogeneous sample

Answer 9

-less desirable but common
-more variability
-less likely to find statistically significant result
-may be earier to generalize: Demonstration of EFFECTIVNESS

Question 10

common inclusion criteria

Answer 10

-age
-gender
-disease/severity
-time since diagnosis
-previous treatment exposure
-concomitant medications

Question 11

Common exclusion criteria

Answer 11

-unacceptable risk: pregnancy
-atypical disease presentation
-less likely to benefit from therapy
-concurrent disease or treatment
-less likely to be compliant with protocol
-diagnostic criteria and disease states must be clearly defined

Question 12

Criteria for causality

Answer 12

-biologically plausible
-concomitant variation
-temporal relationship
-altering the exposure alters the effect
-consistency and reproducibility findings
-all other possible causes eliminated

Question 13

Baseline comparability

Answer 13

-validity relies on comparable groups
-comparability indicates randomization worked!
-statistical adjustment

Question 14

Concurrent therapy

Answer 14

-ethical patient protection
-necessary concomitant therapy should be controlled
-difficult to reproduce use between roups
0can decrease internal valididty