Svingen, Gard Frodahl
2012-May-16 13:21 UTC
[R] Hmisc improveProb() and PredictABEL reclassification () function and continuous NRI
Dear Sirs. I am working with the R packages Hmisc and PredictABEL to make NRI estimates from my Cox models with and without a specific biomarker. According to Pencina et al (Statistics in Medicine 2010, DOI: 0.1002/sim.4085 ), a continuous/non-categorical NRI (NRI>0) is to be used when there are no obvious reason to categorize risk, such as the risk of future cardiovascular events in patients with established cardiovascular disease. My question is therefore: Which value(s) are to be used in the calculation of continuous NRI from the output in Hmisc or in PredictABEL? Does continuous NRI equal total NRI in the output? Yours sincerely Gard Frodahl T. Svingen PhD student the University of Bergen Bergen, Norway [[alternative HTML version deleted]]
Frank Harrell
2012-Jul-30 12:56 UTC
[R] Hmisc improveProb() and PredictABEL reclassification () function and continuous NRI
If you type improveProb at the command line you'll see all the code, which is quite simple. I'm glad you are not attempting to classify risk as this is almost always futile. Frank Svingen, Gard Frodahl wrote> > Dear Sirs. > > I am working with the R packages Hmisc and PredictABEL to make NRI > estimates from my Cox models with and without a specific biomarker. > According to Pencina et al (Statistics in Medicine 2010, DOI: > 0.1002/sim.4085 ), a continuous/non-categorical NRI (NRI>0) is to be used > when there are no obvious reason to categorize risk, such as the risk of > future cardiovascular events in patients with established cardiovascular > disease. > > My question is therefore: Which value(s) are to be used in the calculation > of continuous NRI from the output in Hmisc or in PredictABEL? Does > continuous NRI equal total NRI in the output? > > > > Yours sincerely > > Gard Frodahl T. Svingen > PhD student > the University of Bergen > Bergen, Norway > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@ mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >----- Frank Harrell Department of Biostatistics, Vanderbilt University -- View this message in context: http://r.789695.n4.nabble.com/Hmisc-improveProb-and-PredictABEL-reclassification-function-and-continuous-NRI-tp4630259p4638347.html Sent from the R help mailing list archive at Nabble.com.