Randomised Control Trials

Question 1

Clinical trial

Answer 1

Experiment in which a treatment is administered to humans in order to evaluate its efficacy and safety

Question 2

Uncontrolled trial

Answer 2

Everyone gets treatment

Question 3

Controlled trial

Answer 3

Treated group compared to untreated group or group having normal treatment

Question 4

Randomised controlled trial

Answer 4

Controlled trial with allocation to groups determined by chance

Question 5

Geographical control

Answer 5

Pts w same disorder seen at another hospital/clinic where new intervention not provided

Question 6

Historical control

Answer 6

Pts w same disorder seen in the past before the use of new intervention

Question 7

What type of bias is introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population intended to be analyzed

Answer 7

Selection bias

Question 8

Why is alternate allocation not used for clinical trials

Answer 8

Clinician/patient can predict treatment to be recieved

Question 9

Benefits of randomised controls

Answer 9

Ensure groups being studied are similar
Avoids selection/allocation bias
Only systematic difference between treatment and control groups is the treatment

Question 10

Are trial patients allocated to groups before or after being deemed eligible and consenting to the trial

Answer 10

After

Question 11

Single blind trial

Answer 11

Pt doesn’t know what treatment they are on

Question 12

Double blind trial

Answer 12

Pt and observers do not know what treatment they are on

Question 13

2 types of randomised controlled trial

Answer 13

Parallel
Cross over

Question 14

What is an AB/BA crossover study

Answer 14

Pts in group A and B ->1 group treated 1 not -> outcomes recorded -> groups switch which is treated and which isnt -> outcomes recorded

Question 15

When are parallel trials used

Answer 15

When effect of treatment not reversible

Question 16

When are crossover trials used

Answer 16

When effect of treatment is reversible

Question 17

Advantages of cross over trials

Answer 17

Each pt is their own control
Smaller sample size needed for same nbr of observations
Useful for subjective measurements

Question 18

Disadvantages of crossover trials

Answer 18

More time consuming
Carry over effects

Question 19

How are carry over effects prevented in crossover trials

Answer 19

Washout period between 1st and second treatment periods

Question 20

Cluster randomised trials

Answer 20

pre-existing groups of individuals are randomly allocated to treatment arms, eg villages, schools, gps

Question 21

Factorial controlled trial

Answer 21

test the effect of two or more treatments simultaneously using various combinations of the treatments.

Question 22

What stage of developing a drug uses in vitro and in vivo animal testing

Answer 22

Preclinical

Question 23

Purposes of each stage of drug testing

Answer 23

Preclinical - preliminary efficacy, toxicity and pharmacokinetics in animals
Phase 0 - pharmacokinetics and pharmacodynamics
Phase 1 - safety
Phase 2 - efficacy and safety
Phase 3 - therapeutic effect
Phase 4 - pharmacovigilance

Question 24

Advantages of trial registries

Answer 24

Assist in planning
Avoid research duplication
Encourage collaboration
Optimise use of funds
Incr pt access to info
Improve recruitment
Detect bias

Question 25

How to calculate relative risk of death in treatment group compared to control

Answer 25

Risk of death in treatment/risk of death in control

Question 26

Intention to treat

Answer 26

Comparison of all subjects based on treatment group assigned regardless of whether they complied

Question 27

On treatment

Answer 27

Comparison of subjects who actually took treatment

Question 28

How can compliance in trials be increased

Answer 28

Selection of patients Double blind design Run in period where all are treated to identify those who can’t tolerate treatment

Question 29

How to calculate how many people need a treatment to prevent an event

Answer 29

100/ difference in risk between treatment and control groups

Question 30

Purpose of meta analysis

Answer 30

Bring together all evidence to more powerfully estimate effect size

Question 31

What type of graph are meta analysis results usually shown in

Answer 31

Forest plot

Question 32

Issues in meta analysis

Answer 32

Heterogeneity in study results Publication bias

Question 33

What causes heterogeneity in study results

Answer 33

Different study designs Different participant characteristics Differences in intervention Chance

Question 34

What causes publication bias

Answer 34

Studies with significant/favourable results more likely to be published