0
votes
0answers
32 views

Plotting the effect of a variable estimated by a regression model fit

Plotting the effect of a variable estimated by a regression model fit is quite interesting. However, I have some questions regarding this subject. Here is some example code: ...
1
vote
0answers
32 views

Weighted Kaplan-Meier Curve Log Rank Test

I need to compare two weighted KM curves created by using the svykm function from the survey package. I am unable to find any ...
0
votes
1answer
41 views

AFT model with time varying independent variables

I am a newbie in survival analysis and I would like to pose some simple questions, after reading numerous posts regarding how to perform survival analysis in R. So, what I would like to know is: Can ...
0
votes
1answer
88 views

model selection through shrinkage (Lasso) using glmnet

I would like to use model selection through shrinkage (Lasso) using glmnet. After trying the example of the glmnet manual and tried the procedure with my data. ...
2
votes
1answer
74 views

Impute missing values using aregImpute

I have a data frame with 61 columns. Some data is missing. I read in Steyerberg's book about aregImpute in Hmisc. I used it with ...
0
votes
1answer
40 views

Simulate time to event times based on an existing subset of data

I have to task to predict data volume to be processed for a study that currently has 40 patients, but will have 100 patients eventually. Since most of the data is generated during the treatment phase, ...
0
votes
1answer
44 views

plotting “log relative hazard” against continuous covariate: what are knots when using cph

I try to get into in Cox Regression and read the example chapter from Steyerberg's book. Afterwards I tried to plot log relative hazards against continuous variables using the rms package: ...
1
vote
2answers
47 views

Log-rank / Cox analysis with very unequal sized groups: alternative calculations of p-value?

I would like to set up a series of tests on the difference in survival between two very unequal sized groups. Generally either log-rank (using the R survdiff function) or a cox regression (R coxph) ...
0
votes
0answers
21 views

Simulate KM curves with assumptions in R

I am looking to simulate 2 survival curves under different assumptions on the mean / median process underlying the 2 arms. Has anyone done this in R?
5
votes
1answer
144 views

Calculate incidence rates using poisson model: relation to hazard ratio from Cox PH model

I want to calculate incidence rates to present along hazard ratio's in order to present both relative and absolute measures of risk. I saw in other studies that such incidence rates can be calculated ...
1
vote
1answer
34 views

Standardising input parameters in coxph models

I'm trying to standardize the input variables of my coxph analysis to make outputs more easily interpretable. I've used the following function (Which was ...
-1
votes
1answer
56 views

log-rank test in R

I need to use the survdiff function to statistically compare (using log-rank test) the following survival functions: (1) Male (Sex=1) and Female (Sex=2) (2) ...
0
votes
0answers
20 views

Result of the summary of the proportional hazard model with frailty in R

I am trying to fit coxph a model with frailty with syntax below: ...
0
votes
0answers
21 views

Extended COX model in R [closed]

Objective: To predict time to event of a customer using R I developed a Non parametric model but as per my understanding we cannot perform predictions from these models, so I have to build a model ...
0
votes
1answer
88 views

Is it possible to construct a discrete-time multilevel hazard model in R?

I'm trying to run a discrete-time multilevel hazard analysis comparable to the model proposed by Barber et al. I am attempting to model the hazard of migrating internationally using predictors at the ...
1
vote
0answers
23 views

Would this be a problem that Survival Analysis can tackle? The problem deals with localized durations and uncensored data

I am trying to fit a model in R that doesn't have censoring. In other words, I know that each event will eventually happen. There are several experimental groups with people in each group receiving ...
4
votes
1answer
68 views

It it possible in R to specify a regression formula for the hazard rate for a survival analysis model?

I am currently trying to fit a survival analysis model which has the following survival function: $S(t) = \lambda_i e^{-\lambda_i t}$ but with $\lambda_i = e^{\beta_0 +\beta_1 log(1+X_i)}$ where ...
1
vote
1answer
39 views

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?
1
vote
0answers
60 views

Why are these MLE estimates biased?

I estimate the parameters of survival data with censoring which is simulated from Weibull distribution. The mean time to event was set to 10 by choosing the combinations of shape and scale ...
1
vote
1answer
42 views

survival packages in R that allow for time dependent covariates

Which survival packages in R explicitly allow for time dependent covariates? By explicitly, I mean that the package allows its models to accept a survival object with the form ...
0
votes
0answers
30 views

Is there a way to customize my likelihood function for logit models using speedglm/biglm/glm packages?

My goal is to fit a custom logistic regression/survival analysis function using the optim/maxBFGS functions in R and literally ...
1
vote
1answer
62 views

How does one derive the survival function from an accelerated time failure model in R?

I'm currently working with accelerated time failure models. However, when I fit a model using survreg in R, the predict function ...
1
vote
0answers
59 views

how to use ggplot2 make recursive partitioning survival tree [closed]

can everyone tell me how to use ggplot2 make recursive partitioning survival tree? I know " party " package can make a plot in R, however the plot is not looking good, and all the plots in the rest ...
0
votes
0answers
39 views

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 ...
0
votes
1answer
77 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 ...
0
votes
1answer
65 views

Survival Analysis in R with Grouped Data

I'm just getting started with survival analysis and I'm having trouble finding something in R that will do what I'm looking for. Most of the packages use survival ...
3
votes
1answer
93 views

How to generate survival data with time dependent covariates using R

I want to generate survival time from a Cox proportional hazards model that contains time dependent covariate. The model is $h(t|X_i) =h_0(t) \exp(\gamma X_i + \alpha m_{i}(t))$ where $X_i$ is ...
2
votes
1answer
91 views

Conditional expected lifetime in survival analysis

I want to do survival analysis with the Colon Cancer data in survival package: ...
3
votes
0answers
50 views

Survival Analysis why does probability drop to zero

I'm really new to stats and R and I suspect I'm missing something obvious. I have a set of memberships all who start after a point in time (six months ago). I have done my query to estimate the ...
3
votes
2answers
108 views

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 ...
1
vote
0answers
91 views

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. ...
0
votes
0answers
75 views

How to simulate survival times using true base line hazard function

I want to simulate survival times from the model $\lambda(t|X_1,X_2) = \lambda_0(t) \exp(\gamma_1X_1+\gamma_2X_2)$ where covariates are given by $X_1\sim$Binomial(1,0.5), $X_2\sim$Uniform(0,1), the ...
3
votes
0answers
62 views

Testing significance for pairwise Kaplan-Meier survival analysis between groups and pooled data

I've been working on putting together a survival analysis using Kaplan-Meier and the logrank test. I am doing the testing in R with survdiff(). Each plot has multiple groups/curves, and I've been ...
0
votes
0answers
38 views

Include interaction in multiple imputation - r

I'm doing some imputation models of time until recurrence of tuberculosis (Cox model). This model should include an interaction between the time and the outcome of the previous episode of disease (0- ...
1
vote
0answers
62 views

Error in adding interaction in Cox model?

I'm doing a survival analysis and after plotting the Schoenfeld residuals and test the significance of the correlation of residuals with time, I've decided to incorporate a interaction in the model. ...
2
votes
0answers
68 views

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: ...
0
votes
1answer
56 views

Survival analyses for complicated models

I've just began looking into survival analyses, and I'm having some difficulty interpreting the results. I have a model linear regression model where time ~ x1 * x2 * x3... x9, this model seems to ...
1
vote
0answers
38 views

unique spline for different groups in a linear model (and no spline at all for one group)

I have a problem that has puzzled me for a long time. It involves linear models and spline functions. I need to model "time since diagnosis" when some individuals never had a diagnosis. I use Poisson ...
2
votes
1answer
57 views

Interval censoring

I ran an interval censor survival curve with R, JMP and SAS. They both gave me identical graphs, but the tables differed a bit. This is the table JMP gave me. ...
1
vote
1answer
200 views

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 ...
0
votes
0answers
23 views

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 ...
1
vote
0answers
15 views

How to check out an appropriate survival model?

Maybe this question is too general, but I think it's worthy to post to clarify me some standard procedures in survival analysis. As we know, there are a list of method and models like parametric (exp, ...
1
vote
0answers
66 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 ...
1
vote
1answer
62 views

Variance-covariance matrix of survival model

Suppose I have a survival model like this: ...
1
vote
0answers
46 views

How to predict cumulative hazard in survival analysis?

Suppose I have a survival model like this: ...
0
votes
0answers
355 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, ...
0
votes
0answers
52 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 ...
0
votes
1answer
82 views

R Interpret coefficient from Survreg(dist=“gaussian”) [closed]

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 ...
0
votes
0answers
210 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 ...
4
votes
1answer
115 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. ...