Numbers may not be as great as you think. It depends on what you want to
find, and how precisely you want to find it.
The assumption is that sensitivity is unaffected but that the rules applied
after 24 hours result in a markedly reduced specificity.
If you can specify (lets face it I mean guestimate!!!)
a) at what level you would consider specificity unacceptable
b) how precise you want that estimate (i.e. how wide the confidence
intervals)
c) the event rate (proportion of fractures in the group)
then I can give you a number.
Simon
Simon & Fiona Carley
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http://www.bestbets.org
----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, February 22, 2003 9:02 PM
Subject: Re: Ankle injuries
> I agree with the finding, 24 hours after the injury the punter seems to
> have posterior malleolar tenderness. I can't remember from the original
> papers from Ottawa whether there was a time limit on the patients, theres
> early dementia for you.
> I haven't seen any papers myself on timecourse of symptoms, it seems not
to
> be a feature in most studies.
> Any one out there want to do the work?
> The numbers will need a multisite study I imagine
>
> Andy Volans
> Scarborough
> >
> >It's been my clinical impression over the years that patients attending
> >with ankle injuries over 24 hrs are more likely to need an X ray using
> >the Ottawa guidelines. However the pick up rate for fractures seems
>less.
> There are three possible reasons for this:
> >
> >a) swelling and inflammation spreads over the time period, so that pain
> >on palpation that was initially limited spreads to the posterior aspect
> >of the lateral malleolus.
> >
> >b) I'm seeing a self selected group who present late.
> >
> >c) it's a false observation.
> >
> >I wonder has any paper serially examined the injured ankles on a daily
> >basis to note any change in the clinical signs thus triggering an
> >"indication" for X Ray?
> >
> >
> >Ray McGlone
> >
> >A&E Consultant
> >Lancaster
> >
> >
> >
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