EBM for CCE

Question 1

Odds ratio

Answer 1

An estimate of RR when you can’t calculate risk

Odds of event in exposure group
OVER
Odds of event in control group

Question 2

Meaning of OR or RR > 1

Answer 2

Exposure assoc with higher odds of outcome

Question 3

Meaning of OR or RR = 1

Answer 3

Exposure doesn’t affect odds of outcome

Question 4

Meaning of OR or RR < 1

Answer 4

Exposure assoc with lower likelihood of outcome

Question 5

Relative risk

Answer 5

AKA risk ratio

Risk of events in exposure group
OVER
Risk of events in control group

Question 6

Odds

Answer 6

Events in a group
OVER
Nonevents in the group

*similar to risk for rare events

Question 7

Risk

Answer 7

= probability

Events in a group
OVER
Total number in the group

Question 8

Relative risk reduction

Answer 8

1 - RR

Question 9

Absolute risk reduction

Answer 9

Risk in control group
MINUS
Risk in exposure group

Question 10

Number needed to treat

Answer 10

1 / ARR

Question 11

P value

Answer 11

The likelihood that the difference between groups was due to chance

Question 12

Significant P value

Answer 12

<0.05 (the smaller the better)

Question 13

Prevalence

Answer 13

Existing cases at a particular time point. Expressed as a proportion or percentage

Question 14

Incidence

Answer 14

Number of new cases in a population over a time interval. Expressed as a rate

Question 15

Sensitivity

Answer 15

True positive
OVER
Disease positive (True pos + False neg)

A sensitive test is very good at detecting the disease.

SNOUT - a SeNsitive test when Negative rules OUT

Question 16

Specificity

Answer 16

True negative
OVER
Disease negative (True neg + False pos)

A specific test tends not to give many false positives

SPIN - a SPecific test when Positive rules IN

Question 17

PPV

Answer 17

True positive
OVER
Test positive (Tru pos + False pos)

Question 18

NPV

Answer 18

True negative
OVER
Test negative (True neg + false neg)