Statistics

Question 1

How do you calculate relative risk reduction?

Answer 1

(Experimental event rate- control event rate) / Control event rate

Question 2

How do you calculate the standard error of the mean?

Answer 2

Standard deviation / square root (number of patients)

Question 3

How do you calculate absolute risk reduction?

Answer 3

Control rate of something - Experimental rate of something

Question 4

How do you calculate number needed to treat?

Answer 4

100 / Absolute risk reduction

Then rounded to the nearest whole number

Question 5

What is a type I error?

Answer 5

False positive
Incorrectly reject null hypothesis
Worse error

Question 6

What is a type II error?

Answer 6

False negative

Incorrectly accept null hypothesis

Question 7

What is a cohort study?

Answer 7

Start with exposure and follow them over time to see the outcome

Question 8

What is a case control study?

Answer 8

Retrospective

Start with outcome and look back to see the exposures

Question 9

What is sensitivity?

Answer 9

True positives / All those with disease

Question 10

How do you calculate specificity?

Answer 10

True negatives / All those without disease

Question 11

How do you calculate the positive predictive value?

Answer 11

True positives / All those who tested positive

Question 12

How do you calculate the negative predictive value?

Answer 12

True negatives / All those who tested negative