L 1.6- Critical appraisal

Question 1

What is internal validity?

Answer 1

Describes the extent to which a cause-and-effect relationship established in a study cannot be explained by other factors

Question 2

What are the types of descriptive studies?

Answer 2

Survey (Cross-sectional)
Qualitative

Question 3

What are the types of analytic studies?

Answer 3

Experimental
Observational

Question 4

What are the types of experimental studies?

Answer 4

Randomised parallel group
Randomised crossover

Question 5

What is a randomised parallel group?

Answer 5

All subjects are randomised to one or more study arms and each study arm will be allocated a different intervention.

After randomisation, each participant will stay in their assigned treatment arm for the duration of the study

Question 6

What is a randomised crossover study?

Answer 6

You assess 2 or more interventions. In this design, all participants receive all the interventions, but the order in which they get the interventions is randomised.

Question 7

What are the types of observational studies?

Answer 7

Cohort study
Cross-sectional
Case-control study

Question 8

Why should you do randomised control trials?

Answer 8

High validity, low risk of bias

Question 9

Why should you not do RCTs?

Answer 9

1. Expensive
2. Lag time- concept to implementation
3. Ethical issues/ social acceptability
4. Practical issues (e.g. rare conditions)
   5.Not needed- lack of evidence & lack of implementation

Question 10

What is external validity?

Answer 10

Refers to the generalisability of findings. Are the results relevant to me or others?

Question 11

What is allocation concealment?

Answer 11

Concealing the allocation sequence from those assigning participants into the intervention groups until the moment of assignment. Prevents researchers from influencing which participants are assigned to the intervention or control group.

Question 12

Which groups of people should be involved in blinding in research?

Answer 12

Patients

People treating them

Researchers

People assessing outcomes

Question 13

What does blinding in RCTs do?

Answer 13

Reduce detection and performance bias

Question 14

What is performance bias?

Answer 14

Performance bias is specific to differences that occur due to knowledge of interventions allocation, in either the researcher or the participant

Question 15

What is detection bias?

Answer 15

Detection bias can be described as the possibility for differences between the comparison groups with regard to how the outcomes are measured or assessed

Question 16

What is attrition bias?

Answer 16

Attrition bias is a type of selection bias due to systematic differences between study groups in the number and the way participants are lost from a study

Question 17

What is reporting bias?

Answer 17

Reporting bias may occur when there are concerns with regard to the outcomes reported within the results of a study