I agree with Sachin Dave. Don't bother with LRs in this case. However, a
useful mnemonic in such extreme circumstances is:
SpPIn: Specificity is so high (100%) that a Positive test rules In the
condition.
SnNOut: Sensitivity is so high (100%) that a Negative test rules it Out.
Cheers
At 10:57 1999/09/20 +0000, you wrote:
>
>Why bother with LR's if the test is so good ? I would not waste time on
LR's, if clinically LR has no value (as in this
>case). The idea behind LR's is combining sens. and spec. in one concept
and to make it clinically relevant. If sens. and
>spec. are 100%, I would not even bother with LR's.
>
>Sachin Dave, MD.
>
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>"Toby Lipman 7, Collingwood Terrace, Jesmond, Newcastle upon Tyne. Tel
0191-2811060 (home), 0191-2869178 (surgery)" wrote:
>
>> In message <[log in to unmask]>, Andrew Jull <[log in to unmask]>
>> writes
>> >Dear all
>> >
>> >anybody got any ideas about how to manage LR+ and LR- where the
sensitivity
>> >and specificity are 100%?
>> >
>> Well they calculate out as infinity or 1/infinity don't they?
>>
>> Toby
>> --
>> Toby Lipman
>> General practitioner, Newcastle upon Tyne
>> Northern and Yorkshire research training fellow
>>
>> Tel 0191-2811060 (home), 0191-2437000 (surgery)
>
+++++++++++++++++++++++++++++++++++++++
Dr. Samuel Wiebe
Neurology and Epilepsy
London Health Sciences Centre, University Campus
London, Ontario, CANADA
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