[Cox proportional hazards regression][1] is a very popular, semi-parametric method for survival analysis.

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How can I plot “intcox” interval cox proportional survival curve?

I'm doing survival analysis. I read intcox package manual but it doesn't provide R code for plotting survival curve. Anyone knows how to plot it? Many thanks ...
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Create age and sexmatched pairs to balance Cox regression further (updated)

I analyze ethnic differences in risk of cardiovascular events (CVD) in a cohort study of patients with coronary heart disease. It is known that immigrants have higher risk of CVD and I intend to show ...
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Objective test for proportionality assumption in Cox Regression Model (SAS)?

I was trying to fit Cox Regression (aka Proportional Hazard) model on some cancer data (N=2288). I got the following output from SAS proc phreg: ...
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Logrank test for trend (proportional hazards)

How one can create a logrank test for trend and does it differ from normal logrank test? Any suggestions or literature? Maybe some R examples and functions?
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What’s wrong with this way of fitting time-dependent coefficients in a Cox regression?

I have a Cox proportional hazards model. Judging by Schoenfeld residual vs. time plots and corresponding tests for zero slope, there is clear violation of the PH assumption for several of the ...
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Outliers in proportional hazards model

How can one easily found an outlier in PH model and why are they so important? Can anybody give me some advice or suggest which R function may I use? Thanks for comments and help.
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Meaning of R's coxph output

I am getting below output from coxph function in R. ...
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rms package, getting zero Dxy in validation of cph model

I'm doing Cox proportional hazards analysis using Frank Harrell's rms package (4.2.0), with 3 strata. My model seems reasonably predictive on training data (Dxy=-0.537), but somehow in bootstrap ...
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Compare Cox with ANN

I am trying to compare Cox model with ANN by R but I have some problems. the result of package coxph is hazard but the result of package ...
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How to compare a Cox model with a neural network model [duplicate]

I am trying to compare a Cox model with ANN in R, but I have some problems: The result of package coxph is a hazard rate, but the result of package ...
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Survfit function in R to score a new dataset

I have built a cox proportional hazards model in the R survival package. I want to score new data set using this model. I thought the survfit function would doing this using survfit(original model, ...
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How to use coxph for prediction of event?

I fitted a cox model as: cfit <- coxph(Surv(tr$start, tr$end, tr$event1) ~ imp+sec + cluster(tr$compid)) Now i want to get the probability of event1 for the ...
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Does R square of Cox Regression tells the same thing as Linear Regression R square?

My R square from cox regression is about 0.02, Does it tell me that model is doing really bad? I used coxph in R.
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Combining two separate Cox PH models into one model?

I have two Cox proportional hazards models (in R), using same outcomes and predictors, one for $n_m$ males and one for $n_f$ females. Is it possible to combine them into one equivalent model over all ...
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Complete interpretation of Cox regression output in R

I need help with complete interpretation of this output(below). Can someone explain all (almost all) estimators in this output: what they mean and what is the substantive interpretation. In ...
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Running time dependent covariate model in R, getting warning

I am trying to fit this model, but it's giving a warning message I don't understand: ...
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Assistance with hazard ratios

I want to compare car accident deaths in two groups of people aged 18-24 (lets use this as the reference) and 24-30 after a certain law was changed using a Cox hazard model using SPSS version 22. I ...
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70 views

How to translate R to SQL for a Cox Proportional Hazards model?

I have built a cox model in R using the coxph function in the survival package, and now I need to replicate the model in SQL for scoring. From my understanding, the model has the form described on ...
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Applying Cox proportional hazards model to new data to get absolute risk (Framingham risk score)

I'm trying to apply one of the Framingham cardiovascular event risk scores to a new dataset in order to get absolute risk. D'Agostino 2013 "Cardiovascular Disease Risk Assessment: Insights from ...
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Addition of time before commencement of radiotherapy to Cox Model

I have a dataset from a clinical trial for which all cancer patients received radiotherapy, but at different times following surgical removal of their tumour. So more simply, I have a variable, time ...
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Can someone help me with the interpretation of this cox proportional hazards model and how to cross-validate it?

The question I'm asking is related to this question here and here. And I apologize for asking so many questions here, as I am thoroughly a stats novice and probably my MD thinking is clouding my ...
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spss macro for calculating nri and idi

I try to analyze if the addition of a biomarker to an established model could improve reclassification. Usually I calculate the NRI manually, but I was wondering if there is a macro that could do this ...
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Cox regression problem with time varying covariates

I was working on a cox regression problem and was refering to this link: http://support.sas.com/documentation/cdl/en/statug/63347/HTML/default/viewer.htm#statug_phreg_sect050.htm I have few ...
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Survival analysis in R with left-truncated data

I am doing a survival analysis in R with the survival package. I think I am working with left-truncated data, but I'm not entirely sure how to handle it. I have a ...
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Predicting conditional expected lifetime by Cox model in R

I'm using a Cox proportional hazards model, estimate the hazard rate for Levamisole relative to 5-FU, adjusting for Age and Sex. ...
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Cumulative Hazard Function where “status” is dependent on “time”

This question is in relation to a dataset I've previously discussed here. I'm trying to determine whether a treatment affects not only the number of visits a patient has to the doctor, but also how ...
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Negative Regression Coefficent (Cox Regression)

I'm doing a Cox regression analysis in order to verify the role of two variables on the prediction of disease conversion. Previously, I did a ROC analysis and a logistic regression. All these methods ...
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Testing residuals from a cox model with time dependent covariates

I'm doing survival analysis with time dependent covariates, using the counting process style. I already have a set of models and I want to test de residuals. I'm having trouble with the lack of ...
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Model speedup using weights in R

I need to run a cox-regression on a huge data set (millions) with only a few unique rows (hundreds) and regressing on categorical variable group. I could use just ...
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Evaluating Proportional Hazards with time-dependent variables

I'm doing survival analysis and using the survival package from R to do it. I have 7 variables, 5 of which are time-dependent (all except sexo and peso). Here is my model: ...
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Simulate censored data cox model

I would like to simulate interval-censored data in a Cox model. In the R package intcox I found the following code: ...
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How was this deviance formula for Cox Proportional Hazard derived?

The gbm package in R documents the following deviance formula for CoxPH models http://gradientboostedmodels.googlecode.com/git/gbm/inst/doc/gbm.pdf $-2 \sum w_i \delta_i (f(x_i) - \log(R_i / w_i)$, ...
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When is best to set the origin (time=0) point in a cox-propotional hazard model change analysis

I would like to know the relationship between change in a variable in the three months after a disease, and survival time. I have change in the variable in the first three months. But I am not sure ...
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Cox regression, survival, comparison with historic group, follow-up time

I have two groups of patients, treated at two time periods. I'm comparing survival. In the later group I have 3 years follow up time. In the early group I have of course access to longer follow up ...
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Cox regression with time varying covariates

I am looking for resources on Cox proportional hazards model with time varying covariates. I'm new to survival analysis so I'm looking for something not overly mathematical. I would also appreciate ...
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How to perform a constrast in R for a cox proportional hazards model

I have the following model fit: ...
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Cox regression to see if distribution of disease predicts survival

I'm working with clinical data from a few hundred patients. Every patient was measured at 6 different timepoints with regular intervals. Each patient is assessed on 3 different domains and given a ...
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Violation Proportionality Cox model - Repeat analysis?

I'm new to survival analysis, but I've been reading some papers and books and I got a nice model. However, one of the variables (Sit) does not met the proportionality assumption for the Cox model. ...
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R package to handle gene expression and proportional hazards model

I have survival data with RNA expression. A lot of the data is censored. Is there an R package that does a proportional hazards model where the number of covariates is much larger than the number of ...
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Error term interpretation in the Cox PH model

I am preparing a presentation on Survival Analysis models, with specific focus on the Cox model. I have been using such model (including its competing risks generalization) for some time now, but I ...
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Selection correction variable (non-randomly selected sample / bias) and Cox regression

I found an approach to calculate a selection correction variable for a Cox regression (Lee 1983. Generalized econometric models with selectivity. Econometrica 51: 507–512.): $$ λ = \phi \frac{ ...
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Inferring the statistical tests performed in a paper

I am in great need of help in order to infer the statistical hypothesis tests performed in Xanthelasmata, arcus corneae, and ischaemic vascular disease and death in general population: prospective ...
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p-value zero in hypothesis testing for survival curves

I have done survival analysis. I used Kaplan-Meir to do the survival analysis. Description of data: My data set is large and data table has close 120,000 records of survival information belong to 6 ...
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cox.zph says the standard deviation is zero

I need to compare my observed point vs random points that have been constrained to be relevant to that observation. In my case, I am looking at habitat selection along transects of animal movements. ...
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Different time scales in time-dependent cox proportional hazards

I'm doing survival analysis with time-dependent variables and I have two types of data: birds followed in a biweekly basis and others followed randomly. I think that analysing both types of data ...
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How to have a captured response table for a 2-year prediction base Cox model in R?

My study is about "Churn Risk Evaluation of College Students". I decided to use R software, already had a result for the survival probability of an old data (all the students already left or ...
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Statistics of time dependent variable observable only at end-of-life, given survival data

I have a variable whose value I can only measure at the end-of-life of a product (which is not fixed). The variable's value, continuous and between 0 and 100, may be related to its age at that time. ...
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Cox PH model selection and validation

I am trying to analyze my data using survival CoX PH in SPSS v.19 and also attempting to make different prediction models (without and with a biomarker of interest). I am a clinician (not a ...
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Interaction in Survival analysis

I am a physician and clearly not a statistician (I try to understand why and how to perform the right analysis, but I don't understand the formulas). I am using SPSS v.19 in analyzing my data. I try ...
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How exactly can the Cox-model ignore exact times?

The Cox model does not depend on the times itself, instead it only needs an ordering of the events. How come it doesn't need the time, as all of the models I've seen so far are dependent on the exact ...