Jacob,
Wald and his coworkers prefer to call sensitivity “detection rate” and
unspecificity (i.e. 1 minus specificity) “false positive rate”, respectively
(e.g. Wald and Leck, 2001). The information you quote refers to a point on an
ROC curve. They also have their own ideas about likelihood ratios.
> Why is it then, that when we look at a screening test like triple test or
> nuchal translucency in Downs syndrome, people talk of 80% detection
> for a 5% false positive rate meaning 5% of the population will be
> positive. (Wald NJ & Hackshaw AK, Prenat Diagn 1997; 17:821-9)
>
Best wishes, Peter
--
Prof. Dr. med. B.-P. Robra, M.P.H.
Institut fuer Sozialmedizin und Gesundheitsoekonomie
OvG-Universitaet Magdeburg
Leipziger Str. 44
D-39120 Magdeburg
Fax: +49 391 5414258
Tel: +49 391 5328043
Email: [log in to unmask]
URL: http://www.med.uni-magdeburg.de/fme/institute/ismhe
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