Yes- that's right and in fact we are looking back over our CS rates.
Does seem abit chicken and egg in terms of what you need to know to do a
power calculation as the sample needs to be big enough to detect a
difference but also to do a calculation you need to know what difference
you might be looking for....
What about for a pilot study of the same study with the same primary
outcome?
Thank you for your thoughts.
Best wishes,
Cathy
On 01/06/2012 15:01, Carolyn Roth wrote:
> Right, having re-read the question, I see your point. So in effect, you
> are looking to set the (arbitrary) level against which to judge
> statistical significance?
>
> Might one way of doing it be on the basis of changes to rates over time.
> i.e. use the LSCS rate of 1,3 or 5 years ago?
>
>
> Carolyn Roth
> Director of Undergraduate Programmes and LME
> School of Nursing& Midwifery
> Keele University
> Clinical Education Centre
> Newcastle Road
> Stoke-on-Trent
> ST4 6QG
>
> Tel. 01782 679698
>
>> Hi Carolyn,
>> We have and in order to do a power calculation she asked me to try to find
>> this out.
>> Best wishes,
>> Cathy
>>
>> On 1 Jun 2012, at 12:47, "Carolyn Roth"<[log in to unmask]> wrote:
>>
>>> Hi Cathy, Can't answer your question, but I would have thought you need
>>> to
>>> talk to a statistician with the details of the proposal to get the
>>> advice
>>> you need.\\
>>>
>>>
>>> Carolyn Roth
>>> Director of Undergraduate Programmes and LME
>>> School of Nursing& Midwifery
>>> Keele University
>>> Clinical Education Centre
>>> Newcastle Road
>>> Stoke-on-Trent
>>> ST4 6QG
>>>
>>> Tel. 01782 679698
>>>
>>>> Dear Midwifery research group members,
>>>> I am a consultant midwife at King's College Hospital in London and have
>>>> been a member of this group for a number of years and rarely contribute
>>>> but always find the discussions interesting. Sadly, I don't get to do
>>>> much research in my job, as it really isn't easy to have time for it.
>>>> However, recently I have been involved in the planning of 2 possible
>>>> RCTs and would like to pick the brains of the esteemed members of this
>>>> list.
>>>>
>>>> Would anyone have any suggestions for what would be a clinically
>>>> significant % point reduction in the casaerean section rate if used as
>>>> a
>>>> a primary outcome?
>>>> If so, can you direct me to any evidence or reference that might be
>>>> useful to base this on?
>>>>
>>>> Many thanks,
>>>> Cathy Walton
>>>>
>>>
>
> Carolyn Roth
> Director of Undergraduate Programmes and LME
> School of Nursing& Midwifery
> Keele University
> Clinical Education Centre
> Newcastle Road
> Stoke-on-Trent
> ST4 6QG
>
> Tel. 01782 679698
>
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