EBD - Different Types of Studies

Question 1

What are the levels of studies?

Carry Sams Xylophone CCCRS

Answer 1

Editorials/opinions 
Case series/reports
cross sectional studies
case control
cohort study 
RCTs
Systematic review/meta analysis

Question 2

What is a case series/report?

Answer 2

This is when we report on med history of one or more patients with an outcome of interest

Question 3

What can case series/reports be used for?

Answer 3

to generate a hypothesis which can then be used to create a more robust study

Question 4

What are some disadvantages of case series/reports?

Answer 4

We can’t prove any valid statistical associations - just case present of a patient - we dont know about any other factors and no control is used for comparison

Question 5

What is a cross-sectional study?

Answer 5

This is where we observe a defined population (such as school children aged 8 in Scotland) at a set point in time and analyse the data we obtain (ie caries rates in FPMs)

Question 6

What are some disadvantages of cross-sectional study?

Answer 6

Can be hard to find appropriate control group
recall bias - may not remember something from years ago
time relationship - did disease start before exposure

Question 7

What is cross sectional study used for?

Answer 7

Used to estimate disease prevalence and investigate potential risk factors

Question 8

Disadvantages of cross sectional studies?

Answer 8

Recall bias

causality problem - can’t say one thing causes another

Question 9

what is a case control study?

Answer 9

This is where we study those WITH DISEASE OF INTEREST and chose a suitable control WITHOUT disease and look back in time at exposure to see if theres different factors and try identify potential causes

Question 10

Disadvantages of case control study?

Answer 10

Can be hard to find appropriate control group
recall bias - may not remember something from years ago
time relationship - did disease start before exposure

Question 11

Whats a cohort study?

Answer 11

This is where we recruit participants and follow them up over periods of time and measure their exposure and if they end up with the disease

Question 12

What are cohort studies used for?

Answer 12

Estimating prevalence of disease

investigating disease cause

Question 13

Problems with cohort study?

Answer 13

Expensive and time consuming
if investigating rare disease we need v large sample
controls difficult to identify

Question 14

What is an RCT?

Answer 14

This is a randomised control trial - gold standard clinical trial that provides the strongest evidence

we have a control and treatment group and participants are randomly allocated to one group - double blinded as participant nor researcher doesn’t know who receives what

Question 15

What are the design elements of RCT?

Answer 15

Participants - inclusion/exclusion criteria - are we including young kids or elderly

Outcome - determine what we are measuring

Control - placebo or gold standard current tx (ethics)

Question 16

How do RCTs minimise bias?

Answer 16

Randomisation
Blinding/masking

assigned by computer, phone call to tell which group, participant or clinical doesn’t know

Question 17

What are some disadvantages of RCT?

Answer 17

Difficult to design, conduct - ethics and cost

risk of bias