EBM Flashcards
What is the population studied?
infants born to pregnant 23-36 weeks gestation <49 years, lower risk individuals (no complications or twins)
Who are we evaluating the efficacy of the RSV vaccine in?
the babies
What is special about this study?
only RCT for pregnant vaccines
Is this vaccine bivalent or monovalent?
bivalent
What is the control of the study?
placebo
What was the primary outcome of the study?
severe RSV
medically attended but not severe
Is it typical to have more than one primary endpoint? What effect does more than one has?
No usually one
more probability that results are significant due to chance
How did they fix the issue of higher chance in the study?
statistical significance was more strict
What was the confidence interval?
99.5%
Why are the looking at efficacy up to 180 days?
antibodies giving from mom to baby up to 6 months and to look at safety in a broader way up to 2 years
what is medically attended RSV? What is severe?
see a doc for URTI and positive test for RSV, o2 given
need more O2 and ICU admission
What’s the benefit of the primary endpoints compared to the other RSV studies?
not subjective and more clinically significant lowering
Was there randomization?
duh its an RCT
Were the groups similar?
yes - lower chance of confounding BUUUT didn’t clearly state characteristics of evaluable groups
What are evaluable infants?
Needed 14 days before birth to give vaccine= gives time for vaccine to kick in to evaluate efficacy
Was there ITT?
modified ITT because evaluable groups and drop outs
Was there blinding?
double but not much detail
Was unblinding possible?
sx from vaccine such as fever, aches and chills didn’t happen due to no adjuvant but possible
Any biases?
recall- maybe when asked if baby had any infection
industry funded-not a huge issue
Was study powered? What is it for?
see if chance is low
targeted a certain number of events not population- did not meet it so chance may be an issue
Are results valid?
Obviously - confounding still unknown due to thing not being clear
Calculate RRR at 90 days?
6/3495/33/3480=0.1789
1-0.1789=0.82
If RRR is 81.8 and CI is 99.5% (40-96.3) explain what this means?
best case reduces risk by 96.3 and worst case reduces risk by 40%
Are results statistically significant?
worst case RRR> 20% = significant
Is RRR 20% clinically meaningful?
good question probably
What is not statistically significant in study?
medically attended RSV at 90 crosses 20%= not significant
Calculate NNT if proportions are 0.2 and 0.9?
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.
Is a NNT of 143 good?
not bad
Any s/e?
higher risk of preterm births (if vaccinated earlier), deaths not different but study isn’t powered so we can’t say
Does it translate to higher risk women?
may even more benefits
