Thanks for your reply. Actually, I'm confused about the results in the article "Postoperative nomogram for survival of patients with retroperitoneal sarcoma treated with curative intent" http://annonc.oxfordjournals.org/cgi/content/abstract/mdp298v1
It stated as: nomogram model The Cox model was used as the basis for the nomogram (Table 2). Figure 2 depicts the final nomogram and portrays the association between each variable and survival based on the scoring system derived from this analysis. The concordance index (discrimination) after internal validation with 200 bootstrapping resamples was 0.73 (95% CI 0.710.75). Similarly, Figure 3 illustrates the calibration of the nomogram before and after internal validation with bootstrapping samples. Calibration was excellent with observed outcomes always within 95% CI of the predicted survival probability. Figure 3 is http://i3.6.cn/cvbnm/a9/c8/8b/c01aad248a0b4ae6ef677600614bd4fa.jpg 2009/7/26 Frank E Harrell Jr <f.harr...@vanderbilt.edu> > > zhu yao wrote: >> >> Dear experts: >> >> I am a newbie to R. Recently, I try to make prediction models with R and the >> Design library. >> I have read Prof. Harrell's excellent book. But I did not quite understand. >> I have two problems about the validation and calibration of prediction >> models: >> 1. Can someone explain the results outputted by the validate() function? How >> to get 95% of c-value of validate? > > validate does not provide that confidence interval, unfortunately. > >> 2. How to add 95% ci in the calibration plot? > > That is not provided except for survival models. > > Next time please include your code so we can see what model you are using. > > Thanks > Frank > >> >> Yao Zhu >> Department of Urology >> Fudan University Shanghai Cancer Center >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org 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 E Harrell Jr Professor and Chair School of Medicine > Department of Biostatistics Vanderbilt University [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org 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.
