Study Designs

Question 1

Double-Blinded Randomised control trial

Answer 1

• control group
• randomly assigned
• complete follow up
• patient and therapist blinded
• blind and independent assesor
• measure meaningful outcomes
• between group comparisons

Question 2

Experimental research

Answer 2

Researcher manipulates and controls one or more independent variables
Observes resultant variation in one or more dependent variables
Compare to suggest cause-and-effect relationship

Question 3

Non-Experimental research

Answer 3

Investigations that are descriptive or exploratory
No direct control overstudied variables
Observational

Question 4

Case studies and case series

Answer 4

• Assess a patient who presents with the condition
• Applying the intervention -> measuring the outcome
• consecutive patient series controls for recall bias (but still issues with recall bias)
• don’t control for natural recovery, statistical regression, placebo, Hawthorne, polite patients effect

Question 5

Single-arm cohort studies

Answer 5

Assess a group of patients who present with the condition.
Monitor change in outcomes under treatment
- everyone gets the same treatment
- data reported at the group level
- poor bias control

Question 6

Non-randomised comparison studies

Answer 6

• Includes a control group that doesn’t receive the intervention
• non-randomised selection
• Cant be sure the two groups are comparable

Question 7

Randomised control trial (RCT)

Answer 7

• controls for selection bias by ensuring group equality
• only way to ensure high probability of comparable groups is by random allocation
• higher quality design style

Question 8

Types of comparators

Answer 8

• Head to head trial: treatment A vs treatment B
• Usual care/natural clinical course
• Natural history
• Sham