search for: logrank

how do l programme the logrank test. l am trying to compare 2 survival curves --------------------------------- [[alternative HTML version deleted]]

Hello! I want to compare two Kaplan-Meier-Curves by using the Logrank-Test: logrank(Surv(time[b], status[b]) ~ group[b]) This way I only get the value of the test-statistic, but not the p-value. Does anybody know how I can get the p-value? Thanks in advance! Verena Hoffmann

hie how do you compute the logrank test using R what commands do you use my data looks something like just an example treatmentgrp strata censoringTime survivalTime censoring act.surv.time [1,] 2 2 42.89005 1847.3358 1 42.89005 [2,] 1 1 74.40379 44...

hie is it possible to get the code for the logrank test l just need the chisquared value. thanks --------------------------------- [[alternative HTML version deleted]]

...lly obtain the LR, Wald, and Score test p-values from the coxph.object, as well as the hazard ratio as follows: formula.obj = Surv(days, status) ~ type coxph.model = coxph(formula.obj, df) fit = summary(coxph.model) hazard.ratio = fit$conf.int[1] lower95 = fit$conf.int[3] upper95 = fit$conf.int[4] logrank.p.value = fit$sctest[3] wald.p.value = fit$waldtest[3] lr.p.value = fit$logtest[3] I had intended to report logrank P values with the hazard ratio and CI obtained from this function. In one case the P was 0.04 yet the CI crossed one, which confused me, and certainly will raise questions by review...

hie carried out a comparison of survival curves using the log rank test in R with the values of rho ranging from -2 to 2 in increments of 0.5 the question is at rho=-1.5 the power of the test seems to fluctuate or differ from the trend shown by the other values of rho is the statistical reason for this difference.ie if the power is increasing as i move from 0 to -2 at rho=-1.5 the power either

...ons should update because a bug in the function cif2.ks has been fixed. General information about the package: surv2sample provides various two-sample tests for right-censored survival data. Three main areas and corresponding methods are: * comparison of two survival distributions - surv2.logrank: weighted logrank tests and their combinations (max, sum) - surv2.neyman: Neyman's smooth test and its data-driven version - surv2.ks: Kolmogorov?Smirnov, Cram?r?von Mises and Anderson?Darling test * comparison of two cumulative incidence functions for competing risks data - cif: es...

...ons should update because a bug in the function cif2.ks has been fixed. General information about the package: surv2sample provides various two-sample tests for right-censored survival data. Three main areas and corresponding methods are: * comparison of two survival distributions - surv2.logrank: weighted logrank tests and their combinations (max, sum) - surv2.neyman: Neyman's smooth test and its data-driven version - surv2.ks: Kolmogorov?Smirnov, Cram?r?von Mises and Anderson?Darling test * comparison of two cumulative incidence functions for competing risks data - cif: es...

R Folk: Please forgive what I'm sure is a fairly na?ve question; I hope it's clear. A colleague and I have been doing a really simple one-off survival analysis, but this is an area with which we are not very familiar, we just happen to have gathered some data that needs this type of analysis. We've done quite a bit of reading, but answers escape us, even though the question below

...eCat_all)1 2.6426 0.3784 0.7847 8.8989as.factor(nodeCat_all)2 7.1803 0.1393 2.1720 23.7368Concordance= 0.699 (se = 0.039 )Rsquare= 0.096 (max possible= 0.911 )Likelihood ratio test= 23.33 on 3 df, p=3.444e-05Wald test = 21.76 on 3 df, p=7.312e-05Score (logrank) test = 24.46 on 3 df, p=2.001e-05 I think, this means that the two variables I tested are of interest to build the model with a p-value of about 10e-5. This also mean that having the Herceptincat =1 is significantly different from having a Herceptincat = 0. Moreover, having a nodecat_all iof 2...

Hi All, I'm runnning coxph() on 90 different datasets (in a loop). 1. I'm wondering how can I get "log-likelihood" value from coxph() output. Currently I can only see following: Likelihood ratio test = Wald test = Score (logrank) test = 2. Once I have likelihood value, I would like to extract these from R output (for each data set). Can any one help please, thanks in advance, Xin P.S. OR, may be if anyone can suggest me some other function which can help me with this. [[alternative HTML version deleted]]

Hello, As I am quitte an ignorant user of R, excuse me for any wrongfull usage of all the terms. My question relates to the statistics behind the survdiff function in the package survival. My textbook knowledge of the logrank test tells me that if I want to compare two survival curves, I have to take the sum of the factors: (O-E)^2/E of both groups, which will give me the Chisq. If I calculate this by hand, I get a different value than the one R is giving me. Actually, the (O-E)^2/E that R gives me, those I agree with,...

...-9.16 0 exp(coef) exp(-coef) lower .95 upper .95 Albumin_gproL 0.855 1.17 0.826 0.884 Rsquare= 0.003 (max possible= 0.033 ) Likelihood ratio test = 73.6 on 1 df, p=0 Wald test = 83.8 on 1 df, p=0 Score (logrank) test = 86.1 on 1 df, p=0 > cox.zph(cox_1111) rho chisq p Albumin_gproL -0.0509 0.197 0.657 ---------------------------------------------------------------------------------------------------- Thank you in advance... GSt -- View this message in c...

...e 0.9981 1.002 0.3120 3.193 gapsize:strata(cohort)cohort=September 2.0491 0.488 0.3792 11.074 Rsquare= 0.022 (max possible= 0.993 ) Likelihood ratio test= 1.35 on 2 df, p=0.5097 Wald test = 1.32 on 2 df, p=0.5178 Score (logrank) test = 1.33 on 2 df, p=0.514 Anyone have an idea why this is occurring? Kind Regards Jacob

...P] -1.15 0.316 0.518 -2.23 0.026 exp(coef) exp(-coef) lower .95 upper .95 Drug[T.MXT+CSP] 0.316 3.16 0.115 0.871 Rsquare= 0.086 (max possible= 0.915 ) Likelihood ratio test= 5.75 on 1 df, p=0.0165 Wald test = 4.96 on 1 df, p=0.026 Score (logrank) test = 5.52 on 1 df, p=0.0188 > > > plot(survfit(fit0)) John David Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-152...

I have just uploaded a new package called interval. It does weighted logrank tests (e.g., logrank, Wilcoxon-type tests) on interval censored data. It allows Surv objects and can calculated exact p-values. It calls the perm package, but also allows calculation of scores that may be output to faster permutation packages like coin. There is a full description of the packge an...

Hi all, I have uploaded an update of the interval package, which calculates nonparametric maximum likelihood estimates (NPMLE) of distributions and exact or asymptotic weighted logrank-type tests for interval censored data. An important part of the update is that now the default initial estimate of the NPMLE uses the MLEcens package and is much faster. This increases the speed of the logrank-type tests as well. Other changes are listed in the NEWS file. For details on the packa...

Dear collegues, Using maxstat I am getting the following: > blood <- maxstat.test(Surv(SUPER, FV)~ZAP,data=zap70, smethod="LogRank") Error in maxstat(y = structure(c(24.4301369863014, 26.4164383561644, 18.7835616438356, : couldn't find function "cscores" I do not know the meaning of this problem. Could you please help me on dat? Thank you in advance for your time. Sincerely, Francesc Bosch, M.D. Senior...

...del for discrete choice habitat modelling. However, I'm having a hard time understanding the meaning of the first line the following part of the summary() output: Rsquare= 0.307 (max possible= 0.475 ) Likelihood ratio test= 91.8 on 12 df, p=2.23e-14 Wald test = 26.3 on 12 df, p=0.00977 Score (logrank) test = 58.6 on 12 df, p=4.03e-08 Does anyone know how I can read the 'max possible' R-square? What does it signify? Is it some kind of quasi-correlation; in which case I read it that I have explained 65% (i.e., 0.307/0.475) of the variation? I hope someone can help on this. Thanks in a...

I have just uploaded a new package called interval. It does weighted logrank tests (e.g., logrank, Wilcoxon-type tests) on interval censored data. It allows Surv objects and can calculated exact p-values. It calls the perm package, but also allows calculation of scores that may be output to faster permutation packages like coin. There is a full description of the packge an...