Experimental designs and RCT's

Question 1

Define treatment

Answer 1

Also known as intervention, and is used by researchers or clinicians to improve a patient’s condition

Question 2

What is the treatment effect?

Answer 2

The amount the measured outcome changes from before and after treatment.

Question 3

What are directions of causality?

Answer 3

This refers to which of two variables causes the other.

Question 4

What is confounding?

Answer 4

Refers to the potential mixup that happens with third-variable problem

Question 5

Correlation is not always causation means?

Answer 5

WHen two variables are associated it doesnt always mean one causes the other

Question 6

What is maturation bias?

Answer 6

This occurs when change in a measured outcome occurs naturally over time and that change is falsely attributed to the treatment.

Question 7

Explain detection bias?

Answer 7

This happens when groups are measured differently on outcomes. This can happen when the researchers known which group, treatment or control, the participants are in.

Question 8

Performance bias is…

Answer 8

when treatments dont go according to plan, leading to unintended influences that could magnify or diminish apparent treatment effects.

Question 9

Attrition bias is…

Answer 9

When participants leave the study, usallly due to differences between groups amongst the participants, affecting outcomes.

Question 10

Regulation bias occurs when…

Answer 10

rules or regulations make it harder or easier to do research on some topics

Question 11

What does a case series involve?

Answer 11

Simply, its design has only a treatment followed by outcome measures.

Question 12

What are some threats to validity of causal inferences with case series design?

Answer 12

Maturation, Testing, mortality or attrition bias, instrumentation and statistical regression effects.

Question 13

Summaries statistical regression to the mean

Answer 13

The apparent treatment effects derives from naturally occuring random variation coincidentally related to the treatment.

Question 14

A controlled trial is?

Answer 14

An intervention study where there is atleast one treatment group along with a no-treatment control group, a placebo group or both.

Question 15

What do RCT allow?

Answer 15

Allocation of participants to treatment and control conditions through a chance process, offering more protection against some biases compared with the comparative study

Question 16

What level of evidence are RCT?

Answer 16

Level 2

Question 17

One negative factor about quasi-experiments?

Answer 17

The problem can arise when treatment and control groups arent the same at the beginning of the experiment.

Question 18

Internal validity refers to?

Answer 18

That truth or accuracy of conclusions as applied to the study itself, whether experimental or not.

Question 19

External validity refers to?

Answer 19

whether results and conclusions generalise beyond the study.

Question 20

Does randomisation protect against all internal validty threaths?

Answer 20

NO

Question 21

What does blinding mean, in research?

Answer 21

The reduction of internal validity threats by concealing membership of treatment-control-placebo conditions from researchers and participants while the study is in progress.

Question 22

What is a single-blinded study?

Answer 22

When the participants do not know whether they are receiving the real treatment, a placebo or nothing at all.

Question 23

What is a double blind study?

Answer 23

When researchers and the staff, including those taking measurements or interacting directly with participants, also does not know participants membership of the experimental conditions.

Question 24

What threats does blinding help reduce?

Answer 24

Reduces validity threats from performance and detection bias

Question 25

Does randomisation offer protection against threats to external validity?

Answer 25

No direct protection at all

Question 26

Two examples of threats to external validity that randomisation doesnt help against

Answer 26

Pretest sensitisation and Sampling bias

Question 27

Random allocation refers to?

Answer 27

how members of a sample are put into treatment and control groups, effectively by a chance process, with the aim of equalising the groups on all relevant variables, including those unmeasured, before implementing the treatment.

Question 28

Random selection refers to?

Answer 28

How the study participants are chosen from the wider population.

Question 29

Nominal scales refer to?

Answer 29

categories only, numbers in the a nominal scale are labels only.

Question 30

Ordinal scales are?

Answer 30

about ranking, higher or lower, on an underlying quantitative measure. Also ordering (1st,2nd etc..)

Question 31

Interval scales add?

Answer 31

The feature, compared to the ordinal scale, of equal intervals between all points along.

Question 32

Ratio scales help?

Answer 32

carry all of the information of an interval scale with the bonus of a true zero.

Question 33

What does rate mean?

Answer 33

The number of actual events / number possible

Question 34

Percentage means?

Answer 34

Number of events per 100