Evaluating Therapy

Question 1

1st column of table in RCTs

Answer 1

Treatment
Placebo
Total

Question 2

2nd column of table in RCTs

Answer 2

Outcome present
A
C
A+C

Question 3

3rd column of table in RCTs

Answer 3

Outcome absent
B
D
B+D

Question 4

4th column of table in RCTs

Answer 4

A+B
C+D
A+B+C+D

Question 5

1st row of table in RCTs

Answer 5

Outcome present, outcome absent

Question 6

2nd row of table in RCTs

Answer 6

Treatment, A, B, A+B

Question 7

3rd row of table in RCTs

Answer 7

Placebo, C, D, C+D

Question 8

4th row of table in RCTs

Answer 8

Total, A+C, B+D, A+B+C+D

Question 9

What is the control event rate (CER) in placebo group?

Answer 9

Frequency of event

Question 10

Calculation of CER

Answer 10

C/(C+D)

Question 11

What is Experimental event rate (EER)?

Answer 11

Frequency of event in treatment group

Question 12

Calculation for EER

Answer 12

A/(A+B)

Question 13

Odds of the event of interest in treatment group?

Answer 13

A/B

Question 14

Odds of event of interest in placebo group?

Answer 14

C/D

Question 15

Odds ratio?

Answer 15

(A/B)/(C/D)

Question 16

Another name for absolute benefit increase?

Answer 16

Absolute risk reduction

Question 17

Calculation for absolute risk reduction

Answer 17

EER - CER

Question 18

Calculation for relative risk

Answer 18

[A/(A+B)] / [C/(C+D)]

or
EER/CER

Question 19

Another name for relative benefit increase

Answer 19

Relative risk reduction

Question 20

Calculation for relative risk reduction

Answer 20

ABI/CER

or

(EER-CER)/CER

or

RR-1

Question 21

What is NNT?

Answer 21

Number of patients who would have to receive treatment for one of them to benefit

Question 22

Calculation of NNT

Answer 22

100/ARR

Question 23

Unit of NNT

Answer 23

Percentage

Question 24

Calculation for NNH (number needed to harm)

Answer 24

100/Absolute risk increase

Question 25

Unit for NNH

Answer 25

Percentage

Question 26

What is considered a significant value for NNT

Answer 26

<10

Question 27

What does NNT of 1 mean?

Answer 27

Everyone gets better with treatment, no one gets better with controls

Question 28

What value of NNT represents effective therapies

Answer 28

2-5

Question 29

Difference between trial participants and clinical population

Answer 29

Differences in baseline risk rates

Question 30

What do you need to change if applying RCT data to your own clinical patients?

Answer 30

CER - baseline risk in group w/o intervention

Question 31

What is the name of the new CER for your own clinical sample?

Answer 31

Patient expected event rate - PEER

Question 32

What is the PEER?

Answer 32

Control event rate in local population in which intervention is planned

Question 33

How do get a new ABI from PEER?

Answer 33

RBI x PEr

Question 34

How to get new NNT from PEER

Answer 34

1/ABI(new)

Question 35

How to get new NNT from f value?

Answer 35

NNT(old)/f value

Question 36

What is the f value?

Answer 36

Susceptibility of a local population to a particular outcome