Quantitative 2- Randomised Control Trials

Question 1

What is the underlying theory of experimental methods of RCT’s?

Answer 1

Positivism

Question 2

What does experimental methods involve?

Answer 2

Active manipulation of variables under the control of the researcher and attempt to study how participants will react to the manipulated conditions through monitoring one or more outcome measures.

Question 3

What does experimental methods attempt in doing?

Answer 3

Attempts to establish laws and principles by developing hypothesis that can be accepted or rejected through structured tests under controlled conditions.

Question 4

What is the definition of experimental design?

Answer 4

a formal, systematic process in which numerical data are utilised to obtain information about the world. Also, to describe, test relationships and examine cause and effect.

Question 5

Experimental design are often boasted to be..

Answer 5

the gold standard and the most rigorous

Question 6

What are randomised control trials also called?

Answer 6

Randomised clinical trials

Controlled clinical trials

Question 7

Why do RCT’s follow very strict procedures?

Answer 7

Follow very strict procedures to make the process transparent because they are used in healthcare to test treatment or interventions on people or patients.

Question 8

How are hypothesis established?

Answer 8

Making a statement that predicts a direct relationship between a cause and its effect.
In an experiment it is the researcher’s job to rule out possible causes leaving only the most plausible explanation remaining- trying to isolate the cause and ruling out any other

Question 9

What is a null hypothesis?

Answer 9

It is usual to propose a further hypothesis at the same time, one which stated the opposite position to the original.
First hypothesis is labelled H1 and the null hypothesis is labelled H0.

Question 10

What happens after the hypothesis is established?

Answer 10

Population and sampling
Finding participants who are eligible for the experiment
The participant need to exhibit the same characteristics
Called the study population
Specifying eligibility criteria for inclusion in the study
Randomly sampling from the study population

Question 11

What is the eligibility criteria?

Answer 11

Potential inclusion of all those people who might have the characteristics needed for the study.

• Often easier to state who is excluded first.
• Might want to limit the age range
• Should have a clear explanation of why the particular criteria has been selected.
• Recruitment should be conducted using the principle of informed consent.

Question 12

What is random sampling?

Answer 12

Method of picking a sample from the study population where everyone has an equal chance of being chosen.

Question 13

What is a sample size?

Answer 13

Optimum number of participants
Too many- participants are burdened unnecessarily.
Sample size calculation needs to be made based on the individual feature of the study.

Question 14

What is random assignment?

Answer 14

Assignment of the participants to receive either the new treatment or the placebo.
The purpose: create two groups that are characteristically equal at the baseline.

Question 15

What is concealment?

Answer 15

Blind studies are important to decrease biasness
Controversy about the placebo effect- the idea that people getting the placebo demonstrate relief of symptoms.
RCT need to report the process of concealment .

Question 16

What is double blinding?

Answer 16

Where two parties are unaware of the treatment allocated to the participants.

Question 17

What are the different forms of data?

Answer 17

• Structured observations

- Questionnaires

Question 18

What is intention to treat analysis (ITT)?

Answer 18

All data are analysed according to the trial protocol and the groups to which they were randomly assigned, regardless of their adherence to the entry criteria and the treatment they actually received and regardless of subsequent withdrawals from treatment or deviation from the protocol.
Avoids over-optimistic estimates.

Question 19

What are the different types of bias?

Answer 19

Selection bias
Allocation bias
Detection bias
Observational bias
Attrition bias 
Confounding bias
Recall bias
Publication bias

Question 20

What is selection bias?

Answer 20

systematic difference between those selected into the sample and those not selected. Therefore, not a representative.

Question 21

What is allocation bias?

Answer 21

a systematic distortion of the data as a result of the way in which participants were allocated to the experimental or control group.

Question 22

What id detection bias?

Answer 22

differences in the assessment of the outcome between the experimental and control group.

Question 23

What is observational bias?

Answer 23

contaminated observations by the observer’s belief, prejudice or background assumptions

Question 24

What is attrition bias?

Answer 24

systematic difference in the loss of participants from the experimental and control group.

Question 25

What is confounding bias?

Answer 25

Occurs when a spurious (false) association is made at the analysis stage between the intervention and the measurement . In reality, results from a different or secondary measurement

Question 26

What is recall bias?

Answer 26

Differences in reporting experiences between those who have and those who do not have the outcome of the interest- occurs in retrospective studies.

Question 27

What is publication bias?

Answer 27

Occurs when only the available literature is reviewed concerning a trial rather than all the literature pertaining to the trial.