L02 - Study designs for healthcare

Question 1

What is the AAAA framework?

Answer 1

Assess - What type of healthcare question/ what type of study
Access - Finding the ‘best’ evidence
Appraise - Evaluating the quality of the evidence, interpreting the results
Act - Is evidence relevant to my clinical practice? Should this evidence change my practice?

Question 2

What are the different types of descriptive studies?

Answer 2

1. Cross sectional studies (surveys)

2. Ecological studies

Question 3

What is the difference between case report and case studies?

Answer 3

Report - A detailed report of an unusual condition or occurrence in A SINGLE PATIENT
Series - A detailed report of an unusual condition or occurrence in SEVERAL PATIENTS

Question 4

What are the two types of study designs?

Answer 4

1. Observational

2. Interventional or experimental

Question 5

What is an experimental/ interventional study?

Answer 5

• RF or intervention is deliberately introduced
• RF within investigators control
• Rarely ethical is a known harmful risk factor is involved

Question 6

What is an observational study?

Answer 6

• The RF or intervention occurred outside the investigators control
• Just ‘observing’ the consequences of a natural exp

Question 7

What is an ecological study?

Answer 7

• Observational
• Units of obs are groups of individuals rather than the individuals themselves (i.e. popn of different countries or towns)

Question 8

What are the different types of observational studies?

Answer 8

1. Ecological
2. Cross sectional
3. Case control
4. Cohort study (follow up or longitudinal study)

Question 9

What are the different types of experimental studies?

Answer 9

1. Randomised controlled trial (RCT)

Question 10

Which study type should you use if the clinical question is about frequency and rate?

Answer 10

Cross-sectional; cohort

Question 11

Which study type should you use if the clinical question is about aetiology and risk factors?

Answer 11

Ecological; case control; cohort

Question 12

Which study type should you use if the clinical question is about prognosis?

Answer 12

Cohort

Question 13

Which study type should you use if the clinical question is about diagnosis?

Answer 13

(Special) cross-sectional

Question 14

Which study type should you use if the clinical question is about effectiveness?

Answer 14

RCT

Question 15

Which study type should you use if the clinical question is about patient or professional experience?

Answer 15

Qualitative research

Question 16

What are the different types of bias?

Answer 16

1. Selection bias
2. Measurement bias
3. Attrition bias

Question 17

Definition of bias?

Answer 17

A systematic error in the design, conduct or analysis of a study that results in a deviation from the truth (the true value)

Question 18

What is selection bias?

Answer 18

Systematic different in the way the study participants are recruited to a study or are allocated to groups in a comparative study

Question 19

What is measurement bias?

Answer 19

Systematic difference in the quality (Accuracy) of information/ data gathered from comparison groups in a study

Question 20

What is attrition bias?

Answer 20

Systematic difference between individuals who stay in a study and those who drop out/ are lost to follow up