Evidence Based Dentistry

Question 1

What is critical appraisal?

Answer 1

The process of assessing and interpreting evidence through the systematic consideration of its validity, relevance and results

Question 2

What does PICO stand for?

Answer 2

Population
Intervention
Comparison
Outcome

Question 3

What does CASP stand for?

Answer 3

Critical appraisal skills programme

Question 4

What should be considered when looking at trials?

Answer 4

Is the trial valid - does it conform to PICO
What are the results - effect of treatment
Are the results relevant to your clinical practice

Question 5

What are RCTs?

Answer 5

Randomised controlled trials
Gold standard of study design
Give the treatment option to one group and a placebo/comparator to the other group and observe both outcomes

Question 6

What makes an RCT valid?

Answer 6

Assignment of patients to treatment randomised
All patients who entered accounted for in its conclusion
All patients, health workers and study personnel ‘blind’ to treatment
Similar groups at the start of the trial
Groups tested and treated equally

Question 7

What is absolute risk difference?

Answer 7

The difference in risk between 2 groups
Used to calculate a confidence interval

Question 8

What is a confidence interval?

Answer 8

The range of values the absolute risk difference will take in the population

Question 9

What is the number needed to treat (NNT)?

Answer 9

The number of patients you would need to treat to prevent one patient from developing the disease/condition/outcome
Calculated by 1/ARD

Question 10

What are other measures of effect size?

Answer 10

Odds ratio (OR)
Relative risk or risk ratio (RR)
Percentage risk reduction or relative risk reduction (RRR)