Evidence Based Medicine

Question 1

What’s the best study to determine the prevalence of a disease?

Answer 1

Cross-sectional Study

Question 2

In a randomised controlled trial, what is reduced by randomisation?

Answer 2

Selection bias

Question 3

A psychiatrist has devised a short screening test for depression. A GP decides to use this screening test for his patients. What measures will be identical whether the test is applies to GP patients or psychiatric outpatients?

Answer 3

Test sensitivity

Question 4

What is the best description of ‘external validity’?

Answer 4

The extent to which one can appropriately apply the results to other populations

Question 5

A study that looks at all children born at one hospital in 1 year and measures their height at intervals up to 4 years of age’ is what kind of study?

Answer 5

Cohort study

Question 6

What kind of study would you use if you were investigating the aetiology of a disease?

Answer 6

Case Control Study

Question 7

Define statistical significance

Answer 7

The results of a study are unlikely to have arisen by chance alone

Question 8

What is saturation?

Answer 8

There is no longer any need to sample more people to reach new conclusions or to back up or challenge existing conclusions

Question 9

Define sensitivity

Answer 9

The people within a population correctly picked up with a positive result

Question 10

Define specificity

Answer 10

The people within a population correctly picked up with a negative result