Randomised Controlled Trials

Question 1

Efficacy?

Answer 1

Test an intervention in ideal conditions

Question 2

Effectiveness?

Answer 2

Does the intervention work in the real world

Question 3

What limits confounding?

Answer 3

Randomisation

Question 4

Internal validity?

Answer 4

Extent to which the observed difference between 2 groups can be correctly attributed to the intervention tested

Question 5

External validity?

Answer 5

Extent to which outcomes observed in the study apply to people outside the sample included in the trial ie. generalisability

Question 6

Bias?

Answer 6

A tendency of an estimate to deviate in one direction away from true value

Question 7

Observer and detection bias?

Answer 7

Outcome measure does not adequately capture outcome of interest and does it measure equally between 2 groups

Question 8

Selection bias e.g?

Answer 8

Allocated groups different at outset

Study sample does not represent target population

Question 9

Solution to observer bias?

Answer 9

Blinding to exposure intervention disease status or hypothesis

Question 10

Attrition bias?

Answer 10

Participants dropping out of an RCT

Question 11

Performance bias?

Answer 11

Different treatment of different arms in an RCT i.e one get paid

Question 12

Publication bias?

Answer 12

RCTs do not find between group differences less likely to be published

Question 13

Clinical Equipoise?

Answer 13

Ethical basis for medical research that involves assigning patients to different treatments i.e is one treatment better than other

Question 14

Steering committee?

Answer 14

Individuals who come together throughout the trial to provide an independent oversight on the efficacy and validity of the trial

Question 15

So only which type of study provides experimental evidence for Bradford Hill criteria?

Answer 15

RCT