Hi all:
I thought that medicine A is more
beneficial than medicine B? An NNT of 20 in this case would mean "treat 20
people with A rather than B and 1 out of those 20 will benefit in addition to
those who usually benefit with B". I think the error has been made because
traditionally we look at negative events, e.g. harms rather than benefits and
look to see if a particular treatment will reduce rates of harm or death or
whatever.
Cheers
Anne Lethaby
Hi Olive, Jackie and everyone,
In my humble opinion the statement needs to me
more explicit to be correct. An NNT of 20 means "treat 20
people with B rather than A and 1 extra patient/person will benefit in addition
to those who usually benefit with A".
Hope it is clearer this way.
Regards,
Lubna
Dear
Colleagues,
If anyone is prepared to answer this query I should be
grateful if they would respond to Jackie directly.
All good
wishes,
Olive
NNT query
From:
"Stark, Jackie"
Date:
Thu, 16 Nov 2006 11:30:23
-0000
To:
To:
*Hello,*
*Many years ago
I did some courses about EBM which were run by the
centre and was told
that if there were any queries I could make
contact. I have a query about
a slide that was presented to nurse
prescribers which caused much debate
between myself and the presenter.
I wonder if someone at the centre would
be willing to confirm whether
the final statement *i.e treat 20 people
with *B rather than A and 1
will benefit* is correct?
*My
opinion is that, while the calculation of NNT is correct, the
drugs should
be transposed in the final statement in order for the
statement to be
correct. The full slide read as follows:*
*Medicine A cures 50% of
people*
*Medicine B cures 45% of people*
** *ARR = 5%
**
*RRR = 10%
*Number needed to treat (NNT):*
** *the number of
people you need to give medicine B rather than
medicine A for one to
benefit
*NNT=100/ARR(%):*
** *In this case 100/5 =
20.
** *i.e. treat 20 people with B rather than A and 1 will
benefit.
*If you are able to help I would be grateful as most of
the audience
were completely new to EBM and I feel passionately that they
should
have the best start possible. I am always mindful and grateful for
the
excellent introduction provided for me by your
centre.*
*Best Regards,*
Jackie Stark
Medicines
Management Pharmacist
Humber Mental Health Teaching NHS
Trust
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Beverley
Road
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Hull
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Dr.Lubna A.Al-Ansary, MSc,
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