I have a coxph model which gives me HR of about 2.9 for presence of factor B (factors can be A, B, C, A as baseline in the model), with 95% CI 1.8-4.8 , p<0.001.
When checking the proportionality assumption there is significant evidence that there is a violation On the link is the results of the plot(cox.zph) of the model for factor A. http://img31.imageshack.us/img31/7213/coxzph.jpg My question is how should I understand the smoothing line of the graph, and what is its relation (and the relation of the values on the y-axis) to the beta estimate the coxph function gives me (2.9 for the above example) IF there was no violation and the line of the cox.zph plot was straight, would the y-value of the line be (in this example) log(2.9)=1.06? If there is no violation of the proportionality assumption, does the "intercept" of the line equal the log of the HR that the coxph outputs? Or is the intercept the delta of the beta? Thank you very much JT -- View this message in context: http://r.789695.n4.nabble.com/How-to-understand-the-plotting-of-the-cox-zph-function-tp3788886p3788886.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
