Perhaps something similar to what Sophie is looking for can be done using the -somersd- package, downloadable from SSC. The -somersd- package computes confidence intervals for a range of rank statistics, including Somers' D and Harrell's c (which is the area under the receiver-operator curve for a binary X), and the differences between Somers' D and Harrell's c parameters. In Stata, type
ssc desc somersd
for a description of -somersd-, and
ssc inst somersd, replace
to install -somersd-, and type
net get somersd.pdf
net get cendif.pdf
net get censlope.pdf
to download the 3 .pdf manuals to your local folder. These manuals, and the online help files, contain references to further papers.
I hope this helps.
Best wishes
Roger
Roger B Newson BSc MSc DPhil
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group
National Heart and Lung Institute
Imperial College London
Royal Brompton Campus
Room 33, Emmanuel Kaye Building
1B Manresa Road
London SW3 6LR
UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: [email protected]
Web page: http://www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/
Opinions expressed are those of the author, not of the institution.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Svend Juul
Sent: 17 March 2009 11:08
To: [email protected]
Subject: Re: st: The use of Obuchowski method in Stata? (with ref)
Sophie Royannis wrote:
I would like to know if someone of you have used the Obuchowski method in Stata, and how does it work in this software.
Is there any program which can help me ?
Nancy A.Obuchowski, Cleveland clinic foundation
"Estimating & comparing diagnostic tests accuracy when the gold standard is not binary"
=================================================================
Advice: Give as full a reference as possible, to improve the chance of response. I found:
Obuchowski NA. Estimating and comparing diagnostic tests' accuracy when the gold standard is not binary. Acad Radiol 2005; 12: 1198-1204.
That paper mentions more than one non-binary scenario and Obuchowski discusses more than one method - and I am not sure how to interpret the results.
. findit Obuchowski
gives no hits, so I doubt that Stata has something that corresponds directly to Obuchowski's paper.
Hope this helps
Svend
________________________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Bartholins Allé 2
DK-8000 Aarhus C, Denmark
Phone: +45 8693 7796
Mobile: +45 2634 7796
E-mail: [email protected]
_________________________________________________________
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
