# Tagged Questions

8 views

### Is there an R function to do a survival analysis with right censoring + nested + crossed factors

I have this dataset to model, but I'm not sure how to do it. I want to model the surviving probability of different populations of two species depending on a treatment applied. Populations should ...
26 views

### Variance-covariance matrix of survival model

Suppose I have a survival model like this: ...
22 views

### How to predict cumulative hazard in survival analysis?

Suppose I have a survival model like this: ...
16 views

### Using a Decision Tree Algorithm such as C4.5 to understand population Partition

I have multivariate data about a certain population with more than 1000 attributes per exemplar. Some of the variables are basic demographics attributes including: gender, age, race, ethnicity, ...
21 views

### Time-scale in cox porportinal hazards model with multiple time-dependent variables

I'm doing survival analysis and I have three time-dependent variables, with different time scales each. I've already done univariate analysis and I want to proceed with multivariate analysis. My ...
17 views

### R Interpret coefficient from Survreg(dist=“gaussian”)

I was wondering if anyone could help me on how to interpret the coefficient from an analysis I have carried out in R (survival package). The data is right ...
55 views

### Predict probability of failure in R using survreg

I am fitting a weibull model as follows: s <- Surv(DFBR[,"Time"],DFBR[,"Censor"]) wei <- survreg(s~ Group+ UsefulLife, data = DFBR, dist="weibull") How ...
63 views

### How would you visualize the difference between Cox/Weibull regression?

I'm trying to figure a way of properly displaying the difference\resemblance between various regression values on the same data set, using cox ph, weibull regression and log-normal regression. ...
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### Confidence interval for the restricted mean in survival analysis

What is the recommended way of calculating confidence intervals for the restricted mean in survival analysis? Here are some example data, taken from the paper Chris Barker (2009), The Mean, Median, ...
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### Two-state model with transient states for panel data

I need to analyse unbalanced panel data where the variable of interest is a dummy with two non-absorbing states (i.e. switch from 0 to 1 and 1 to 0 is possible at any time period). The goal is to ...
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### How to use Cox proportional hazards model in interval-censored data with time-dependent variables?

The question is self-explanatory. I have survival data (n=156) which, in about half of the observations, is right-censored or interval-censored. I'm am using R to do the analysis and I know I can use ...
58 views

### Survfit function for gbm cox model

I just fitted a boosted regression coxph model: cox=gbm(Surv(periods, event) ~ grade + fico_range_low + revol_util + dti, data=notes) However, I want to obtain ...
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### How to calculate Prob > chi2 in R to test model fit of conditional logistic regression

I used the clogit function (from the survival package) to run a conditional logistic regression in R with a big dataset of 1:M matched pairs with n=300368964 and number of events= 39995. ...
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### Why do coxph() and survreg(, dist=“exponential”) NOT return the same coefficient (except for expected opposite sign) in R?

If I understand correctly, the coefficient of a covariate X under a Weibull accelerated failure time (AFT) model is related to the ...
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### How to use Turnbull's nonparametric estimator for interval-censored data in R

I am doing Survival Analysis with interval-censored data and I want to apply Turnbull's nonparametric estimator to the analysis of the covariates (suggested by Turnbull (1976)). I want to know if ...
63 views

### Comparison of CPH, accelerated failure time model or neural networks for survival analysis

I am new to survival analysis and I've recently learned that there are different ways to do it given a certain goal. I am interested in actual implementation and appropriateness of these methods. I ...
116 views

### how does Cox proportional hazards model deal with time-dependent variables

When considering time dependent data in survival analysis, you have multiple start-stop times for an individual subject with measurements for the covariates. If each season has a different size (for ...
40 views

### Decision to add all predictive variables in Kaplan-Meier and Cox PH

In R's survival and rms packages, Kaplan-Meier (Surv and ...
93 views

### What is the parameterization of exponential distribution for survival in Stata?

I'm new to data analysis so this is kind of a simple question. I would like to understand why I cannot reproduce a survival curve generated by a fitted exponential model from Stata. I use the ...
301 views

### R neural network model with target vector as output containing survival predictions

Overview I want to simulate the survival prediction using neural networks described in this paper entitled "Application of Artificial Neural Network-Based Survival Analysis on Two Breast Cancer ...
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### Interpretation of survival risk predictions generated from R's predictSurvProb

I am starting to learn R and its power for giving survival predictions. Abstract I use the predictSurvProb function from the ...
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### Using the calibrate function in rms package for Cox model: use 'hare' method or 'KM'?

I'm creating a calibration plot for my breast cancer prognostic Cox model, which doesn't include any fancy transformations, using the calibrate() function in the ...
152 views

### Making a cumulative incidence plot in R

Background I have a survival object in R called km. ...
133 views

### How to simplify coxme survival models?

I have some questions about specifying a coxme (mixed-effects Cox proportional hazards) model in R and then simplifying it after reading the ...
154 views

### Obtaining R pec survival patient risk percentage

Introduction I have a 300,000-row cancer dataset with around 60 variables (cancer stage, year of diagnosis, radiation therapy, histology, etc.) with a time variable ("number of months survived") and ...
81 views

### Coefficients from a penalized Cox PH

I'm using the R package Penalized (0.9-42) on a Cox PH model. I'm using L2 (Ridge) on the grounds that I don't want to shrink my coefficients to 0. I don't understand why when I ask for: ...
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### Mean residual life with censored observations and covariant eps

I have a time variable ( time of claim settlement after occurrence ) that may be censored ( claim still open at the moment of observation) and some additional covariates ( line of business, claim ...
366 views

### Risk table for a Kaplan Meier plot in R

I need to make a Kaplan Meier plot with a risk table beneath it. Otherwise stated, I need a table of the number of subjects at risk at different time points aligned below the figure. I found a website ...
40 views

### Survival analysis cycle time dependent variable

I've a survival analysis study going on and I'm having trouble with dealing with time-dependent variables. To deal with time-dependent variables I have to create intervals when the variable changes. ...
185 views

### Predicting absolute risk using cox regression

I am trying to use R to predict the absolute risk of developing adverse events in a cohort, and to compare that with the observed outcome. Should I use survreg or ...
163 views

### How do I use the “survival” package and “Surv” function in R with left-truncated data?

I am trying to run survival analysis using the Surv and survfit functions from the survival ...
96 views

### obtaining Standard Errors in maximum likelihood estimation

I am trying to obtain the standard errors of my maximum likelihood model, I am having trouble to fix the error message: ...
243 views

### Generating survival times for a piecewise constant hazard model with two change points

When there are two change points in a piecewise constant hazard model then the density function becomes some triangle exponential distribution. In this situation I can't generate the survival time ...
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### Structure of data and function call for recurrent event data with time-dependent variables

I'm attempting to estimate the effect of 2 drugs (drug1, drug2) on the likelihood of a patient falling (...
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### Survival Analysis — Probability Definition and Distribution application

edit: I think really the crux of my question is more meta, really how should I think of survival data and how do I know what kind of distribution I should fit into it? Are there any resources on how ...
145 views

### Parametric modelling of customer lifetime value using survival (Cox) analysis

I have half a year long data of purchases in e-commerce site (100K purchases by 60K customers). In simplest A/B testing framework random customers got a discount on the next purchase after order ...
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### Meta analysis of summary data or model of raw data?

I have data of the following form: Sample MeasureZZ Time Event S1 M1 t1 e1 .... I have calculated the influence of ZZ on survival by ...
97 views

### Calculate variance of survival estimate generated from 'baseline' of coxph

Short version: calculate variance of estimator of survival for a new subject (new covariates) where the coefficients for the covariates have been calculated from existing data. Sorry this is so long, ...
1k views

### How to estimate baseline hazard function in Cox Model with R

I need to estimate baseline hazard function $\lambda_0(t)$ in a time dependent Cox model $\lambda(t) = \lambda_0(t) \exp(Z(t)'\beta)$ While I took Survival course, I remember that the direct ...
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### Cross-validation in gamma frailty model

Does anyone know how to do cross-validation in a gamma frailty model in R? I am using the survival package, which uses the ...
222 views

### Estimate Survival Function from hazard function — an inconsistent result between basehaz and survfit function

I am trying to caculate survival function in a time dependent covariates Cox model from its baseline hazard function. However, my program gives a different result compared with ...
73 views

### Competing risk data

I want to simulate survival time for two competitive events using R. Consider that there are no censored data, and the survival time for each event has exponential ...
148 views

### Using R, how can I plot survival curves of Cox PH model with time-varying covariates?

I've been following the R code from page 74 of this link to plot a survival curve given a set of independent variable values. Note that the author uses ...
553 views

### coxph ran out of iterations and did not converge

Yes, I have checked that previous answers to "Ran out of iterations..." questions do not solve my problem. I have fault data on Firefox, 899 faults and 1395 (estimated) censored faults. The ...
119 views

### Fitting survival/hazard model to probability of default

I will very grateful with some help on the following problem: I need to forecast probability of default for portfolio of retail loans, depending on several factors, that can be divided into three ...
110 views

### Path Analysis from cookie data using Survival Analysis?

I have a data analysis task where I need to assign value to various advertisement exposures that lead to an online purchase. The various types of exposures are recorded in sequence but there is no ...
86 views

### Feed forward neural networks for the analysis of censored survival data, how should I implement it in R?

Recently, I have read an article which name is “Feed forward neural networks for the analysis of censored survival data: A partial logistic regression approach”. Without a math background, I catch ...
151 views

### Applying Kaplan-Meier survival function estimate to get expected number of events

I have the Kaplan-Meier estimate for the survival function which I obtained using R's survival package: ...
419 views

### How to simulate a Cox proportional hazards model with change point and code it in R

I have a model that has the following characteristics: The covariate $X$ follows a $Be(1/3)$. If $X=0$, survival time $Y$ follows an $E=Exponential (1)$. If $X=1$, survival time $Y$ is generated as ...
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### Survival analysis with ridge regression in R give same results with different random seeds

I am doing survival analysis using ridge regression. I'm using this R command: coxph(Surv(time, status) ~ ridge(x1, x2, x3), data=DATA) As far as I know, ...