Why we need randomised control trials?

Question 1

What is the regulatory body for trials?

Answer 1

CONSORT: Consolidated Standards of Reporting trials

Question 2

What is a clinical trial?

Answer 2

Planned experiment to determine the most appropriate treatment for patients with a given medical condition.

Question 3

What is an RCT?

Answer 3

Randomised controlled trial where patients are sorted into an intervention group and control group. It has the highest level of evidence and free of internal validity. It is based on the external validity if it can be generalisable.

Question 4

How are drugs approved?

Answer 4

When the Potential benefits outweighs potential harm

Question 5

What is drug development pathway?

Answer 5

It begins with drug discovery, pre-clinical development, clinical development and post-marketing surveillance.

Question 6

What is the impact of RCT opposition?

Answer 6

Unproven harmful treatments are provided to patients and there is a lack of researcher control over the variables which means establishing causation and conclusions were difficult.

Question 7

What are the classifications in a clinical trial?

Answer 7

Population, main focus, dose, main outcome measures.

Question 8

What is a concurrent control?

Answer 8

Participant/group is selected at the same time as another group such as a control to study the effect of the test treatment. Example of a concurrent control group is a placebo group.

Question 9

Difference between concurrent control and historical control

Answer 9

Concurrent control is a subject whom enrolled simultaenously with the treatment group, same source population and same study period. Historical control is a subject treated in the past with a standard care form used for comparison.

Question 10

What are the alternatives to randomised control trials?

Answer 10

Observational studies- difficulty establishing causation
Quasi-experimental study- difficult to use for non-linear trends
Case series
Concurrent controls
Historical controls

Question 11

What is the issue with a case series study?

Answer 11

There is no control, no direct comparison and evidence.

Question 12

What is the issue with historical control?

Answer 12

Must consider different age, gender, socioeconomic status and prognoses for valid comparison.

Question 13

What is regression to the mean?

Answer 13

A group is measured with an inexact measurement tool and re-measured. Individuals with extreme values will have a high probability of regressing back to the mean on second measurement. It is used to predict that patients with unusual response to treatment are outliers who will eventually have normal response to treatment if continued.

Question 14

What can before/after studies?

Answer 14

Comparing the participants before and after the study. Improvement may be attributed to regression of the mean.

Question 15

What is temporal factors?

Answer 15

Considering the differences in the intervention group and control group which may impact the results. This includes frequency of treatment, rate and duration in assessment of treatment response.

Question 16

What to consider with concurrent control?

Answer 16

How similar patient groups being selected and considering the systematic differences such as socioeconomic factors and volunteer bias. Evaluation of this may not always be consistent and can include assumptions.

Question 17

What is internal validity?

Answer 17

Observed effects are unbiased for those involved in the study. Eternal validity is how generalised the study can be to the general population

Question 18

What is performance bias?

Answer 18

Systematic differences between groups that are treated/provided with care other than the intervention which affects results. This can be reduced through blinding

Question 19

What is detection bias?

Answer 19

Systematic distortion of the results of a randomised trial due to knowledge of the group assignment. This can be by the participant or the investigator.

Question 20

Why are trials randomised?

Answer 20

Eliminates systematic bias, ensure balance across comparative groups and differences in outcomes can be attributed to intervention.

Question 21

What are the advantages of RCTs?

Answer 21

Eliminates systematic bias to ensure balance across comparative groups. Randomised groups can be followed up over the same time to attribute differences in outcome to the intervention only. It is ethical and equipoise (unawareness of which intervention is better.)

Question 22

What is cluster RCTs?

Answer 22

Randomisation of pre-existing groups like countries to control intervention conditions. It decreases the effective sample size and statistical power because people within an organisational unit are more similar than those across.

Question 23

How to ensure balance of factors?

Answer 23

Using stratified sampling or adjust for it in the analysis.

Question 24

What is biased allocation?

Answer 24

Creating randomisation lists based on coin toss or odd/even DOB but this can lead to unbalanced groups. These methods should be concealed from the person delivering and assessing.

Question 25

What is blinding?

Answer 25

Concealment which can be the allocation, outcome assessment or placebo.

Question 26

What is allocation concealment?

Answer 26

Preventing selection bias by concealing allocation sequence from assigning participants until the participation.

Question 27

What is the criteria for sample size?

Answer 27

Large enough group for high probability of detecting a clinically important difference.

Question 28

What is an underpowered sample size?

Answer 28

Not enough subjects which can cause type 2 error. Too many subjects is an overpowered sample size

Question 29

What is primary outcome?

Answer 29

Most important outcome which must be appropriate to the research question.

Question 30

What is effect size?

Answer 30

Quantifying the difference of treatment efficacy which measures its strength

Question 31

What is an MCID?

Answer 31

Minimal clinically important difference- smallest amount an outcome must change to be considered meaningful progress for patients.

Question 32

What is intention to treat analysis?

Answer 32

Includes all randomised participants who received the intervention treatment

Question 33

What is per-protocol analysis?

Answer 33

The comparison of treatment groups of patients that were originally allocated it and completed it