EBM

Question 1

What is the population studied?

Answer 1

infants born to pregnant 23-36 weeks gestation <49 years, lower risk individuals (no complications or twins)

Question 2

Who are we evaluating the efficacy of the RSV vaccine in?

Answer 2

the babies

Question 3

What is special about this study?

Answer 3

only RCT for pregnant vaccines

Question 4

Is this vaccine bivalent or monovalent?

Answer 4

bivalent

Question 5

What is the control of the study?

Answer 5

placebo

Question 6

What was the primary outcome of the study?

Answer 6

severe RSV
medically attended but not severe

Question 7

Is it typical to have more than one primary endpoint? What effect does more than one has?

Answer 7

No usually one
more probability that results are significant due to chance

Question 8

How did they fix the issue of higher chance in the study?

Answer 8

statistical significance was more strict

Question 9

What was the confidence interval?

Answer 9

99.5%

Question 10

Why are the looking at efficacy up to 180 days?

Answer 10

antibodies giving from mom to baby up to 6 months and to look at safety in a broader way up to 2 years

Question 11

what is medically attended RSV? What is severe?

Answer 11

see a doc for URTI and positive test for RSV, o2 given
need more O2 and ICU admission

Question 12

What’s the benefit of the primary endpoints compared to the other RSV studies?

Answer 12

not subjective and more clinically significant lowering

Question 13

Was there randomization?

Answer 13

duh its an RCT

Question 14

Were the groups similar?

Answer 14

yes - lower chance of confounding BUUUT didn’t clearly state characteristics of evaluable groups

Question 15

What are evaluable infants?

Answer 15

Needed 14 days before birth to give vaccine= gives time for vaccine to kick in to evaluate efficacy

Question 16

Was there ITT?

Answer 16

modified ITT because evaluable groups and drop outs

Question 17

Was there blinding?

Answer 17

double but not much detail

Question 18

Was unblinding possible?

Answer 18

sx from vaccine such as fever, aches and chills didn’t happen due to no adjuvant but possible

Question 19

Any biases?

Answer 19

recall- maybe when asked if baby had any infection
industry funded-not a huge issue

Question 20

Was study powered? What is it for?

Answer 20

see if chance is low
targeted a certain number of events not population- did not meet it so chance may be an issue

Question 21

Are results valid?

Answer 21

Obviously - confounding still unknown due to thing not being clear

Question 22

Calculate RRR at 90 days?

Answer 22

6/3495/33/3480=0.1789
1-0.1789=0.82

Question 23

If RRR is 81.8 and CI is 99.5% (40-96.3) explain what this means?

Answer 23

best case reduces risk by 96.3 and worst case reduces risk by 40%

Question 24

Are results statistically significant?

Answer 24

worst case RRR> 20% = significant

Question 25

Is RRR 20% clinically meaningful?

Answer 25

good question probably

Question 26

What is not statistically significant in study?

Answer 26

medically attended RSV at 90 crosses 20%= not significant

Question 27

Calculate NNT if proportions are 0.2 and 0.9?

Answer 27

Absolute= 0.9-0.2= absolute reduction by 0.7%
NNT= 100/0.7=143
need to treat 143 babies need to be born from a vaccinated mother to get one additional severe RSV infection.

Question 28

Is a NNT of 143 good?

Answer 28

not bad

Question 29

Any s/e?

Answer 29

higher risk of preterm births (if vaccinated earlier), deaths not different but study isn’t powered so we can’t say

Question 30

Does it translate to higher risk women?

Answer 30

may even more benefits