Do we really loose any information when it comes to applicability of LR's
to a clinical problem ?
Let us say for example there are 3 tests A, B, C with sens. and spec. as
outlined by you for a given disease. My bottom line would be what is the
post-test probability of that disease given a positive result of test A or
B or C. Does post-test probability change ? Would clinician care for the
sens. or specificity of the test A or B or C ? What he wants to know is
how sure he can be about a disease given a positive test result.
Sachin Dave, MD.
Atle Klovning wrote:
> The holy LR is a vast step forwars in understanding tests- BUT when
> combining sens and spec into ONE measure- we lose information. E.g. at
> times having a test with high specificity is very important, whereas at
> other times high sensitivity is the thing you want.
>
> Also, and quite disheartening:
>
> A sens 40% and spec 98% => LR+ =20 and
> B sens 80% and spec 96% => LR+ =20 and
> C sens 100% and spec 95% => LR+ = 20
>
> A, B and C should generate very different test interpretations
>
> *******************************************************************
> Atle Klovning, MD, Research Fellow,
> Specialist in General Practice/Family Medicine
> Div. for General Practice,
> University of Bergen, Norway
> (+47) 55 58 67 09
> (+47) 55 58 67 10 (FAX)
>
> http://www.uib.no/isf/people/atle/
>
> *******************************************************************
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