The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [survival]

Survival analysis models time to event data, typically time to death or failure time. Censored data are a common problem for survival analyses.

Filter by
Sorted by
Tagged with
0
votes
0answers
7 views

Finding exposures given a risk set and an MLE

I'm tackling advanced use of a Cox proportional model and I've been given the exposure times for two risk sets shown below $ R_{_1}: 7,8,11,15,19 $ $ R_{_2}: 6,8,10,13,18 $ I've also been given the ...
1
vote
1answer
10 views

Must the hazard function integrate to infinity?

Consider a non-negative random variable $T$ arising in the context of survival/reliability analysis (usually representing the time until some event occurs). In some recent comments to an answer on ...
0
votes
0answers
8 views

Parametric shared frailty models with individual monotone yet population non-monotone hazard

I'm fitting parametric survival models with/without shared frailty on individuals. The hazard in my data is very low at first, then increases and finally decreases again, sort of a bell shaped curve. ...
2
votes
1answer
25 views
1
vote
0answers
146 views

Including a baseline risk for each participant to consider having a different number of data points in Cox model

We used the Cox model to associate environmental exposures with time to heart failure using cohort data. The following question has been raised: When using the extended Cox model, did you include a ...
0
votes
0answers
5 views

How to test goodness of fit for AFT Survival Models?

I am testing a few survival models in the parametric family and would like to test the goodness of fit of the models to the data I have. Which tests would be useful and is it even necessary to carry ...
0
votes
0answers
18 views

Multi-level survival modeling

I'm struggling with choosing the appropriate model for a study I'm doing where I determine the survival times of certain technological applications. The goal here is to estimate how long individuals ...
0
votes
0answers
23 views

survreg predict default options

Given a suvreg model, for example, lfit <- survreg(Surv(time, status) ~ ph.ecog, data=lung) I get the same result if I ...
0
votes
0answers
18 views

How to better understand when to use Weibull AFT versus Cox Model for Failure Data

I am struggling to understand when I should consider using a Cox regression model versus using a Weibull AFT model to predict the end of life of mechanical components. I have tried to apply the Cox ...
2
votes
0answers
28 views

Determining between using Discrete vs Continuous Survival Analysis

This is a follow up question based on what has been explained here: Survival analysis: continuous vs discrete time but I wish to further confirm it for my case. I have a dataset collected over a ...
0
votes
0answers
22 views

Predicting hazard in an AFT Weibull model

I have fitted a Weibull Accelerated Failure Time model and my question is how to obtain the hazard. For example in Stata, after fitting a model with streg, typing predict newvar, hazard obtains the ...
0
votes
0answers
7 views

Cusum analysis on a Time-dependent outcome [closed]

Good morning everyone, I need to perform a statistical analysis to study the learning curve of a surgical procedure, by taking into account its performance a time-dependent outcome (Survival). How ...
0
votes
1answer
52 views

Simulation in R of data based on Cox proportional-hazards model for power analysis

I would like to fit data based on Cox proportional-hazards model and then simulate new data based on a fitted model. For instance, provided that the fit is ...
2
votes
0answers
23 views

Cut off age for mortality data

I have data with death rates for each year 1921 to 2014; and for each age 0 to 110 as below: ...
1
vote
1answer
21 views

Probabilistic estimates of Kaplan-Meier curves using S(t) and std.err for each time point

I am working on a survival analysis where I am fitting different parametric models to survival data. Varying the models that I have fit to the data is straightforward, via Cholesky decompositions- but ...
0
votes
0answers
6 views

Statistical bias/methodology question about interaction test in a retrospective survival analysis

I have a question relating to statistical bias. Here is a summary of my study: Study design: Retrospective cohort Patient population: Melanoma patients getting immunotherapy Exposure of interest: ...
1
vote
0answers
21 views

The relation between copula and survival copula

There are two relations connect between copula distribution function and copula survival function I got confused between them $¯C(u,v)= u + v -1 + C(1-u,1-v)$ $C(u,v)= 1 - ¯C(1-u) - ¯C(1-v) + ¯C(1-u,...
0
votes
0answers
15 views

How to obtain predicted time to event using survival analysis?

I have a dataset with right censored data and I have fitted a cox regression model on it but I realised that the output of the model is a hazard rate rather than a prediction of time to event. I have ...
1
vote
1answer
16 views

Null Target Variable

I am trying to predict - Number of days it takes for a customer to make the second purchase. Sometimes the customer comes back in 2,5,6,10.... days and sometimes the customer does not come back which ...
2
votes
1answer
50 views

Generating Failure Times

I have 1800 units and I know the probability of failing for each unit every week for 2000 weeks. I would like to obtain some failure times for each unit. One way to do this could be to use a ...
0
votes
0answers
4 views

Error in eval(predvars, data, env): object 'year' not found [migrated]

I do have a question about calculating relative survival compared with observed survival with the package relsurv. Posting a reproductive example: For this, we need the package relsurv ...
0
votes
1answer
46 views

Calculating the Expected life of network with hazard functions

I have been asked to solve some questions in the statistical program R. First, I want to find the expected life length (by numeric integration) of a network with 3 parallel components (T1,T2,T3) and ...
0
votes
0answers
13 views

Comparing the predictive powers of survival models using Harrell’s C in R

My question is quite concrete. Does anybody know if the approach published in [1] to compare the performance of two models using the Harrell's C or Somers’ D is available in R? I've done a search ...
3
votes
0answers
34 views

proportional hazards model with fixed interval censoring = cloglog GLM with fixed effect of time?

Consider a survival analysis with time-constant coefficients, interval-censored, where the observation intervals are consistent across all individuals (e.g. each individual is observed at the end of ...
0
votes
1answer
31 views

R survdiff interpretation

When I use survdiff in R for survival analysis, I know how to interpret the term labeled ...
1
vote
1answer
35 views

What does the output of a Cox Proportional Hazard model mean?

For a linear regression plugging different X values to the fitted model gives us the different predicted Y values, for a logistic regression we get the different log odds: what does the output of the ...
4
votes
0answers
47 views

Correlation between logrank (log-rank) test statistics with common control

Say I have a $K$ arm experiment that generates survival (time-to-event) endpoints. There are $K-1$ experimental arms and a single control arm. Say I compute a log rank test statistic comparing the ...
0
votes
0answers
5 views

Sensitivity Analysis to Compare Distributions within a Fully Parametric Model

I am attempting to run a fully parametric survival analysis on a dataset of mine. My data is right-skewed with a long tail, and multiple different distributions appear to fit my data well (e.g. ...
0
votes
1answer
22 views

Multiple cox regression with no events in one group of one variable — survival analysis

I am trying to run a multivariate Cox regression analysis but I have 1 value for 1 variable that has no events reached. This variable was treatment (values = treatment 1, treatment 2, treatment 3, and ...
0
votes
0answers
11 views

Simulate recurrent events data where last observation is censored

I would like to simulate a recurrent events dataset for survival analysis with cox regression in R. The data should have the following properties: multiple, varying number of observations per ID only ...
0
votes
0answers
10 views

Negative Log Likelihood for Censored Data

I'd like to use negative log likelihood as an objective function to model roughly gaussian data with right censoring. My objective function will look something like the following, but I'm not sure how ...
0
votes
1answer
17 views

Test that at least one hazard is greater than hazard in control

I have an experiment with one control and three experimental arms, A, B and C. My experiment generates survival data. I have survival times for each group, $T_{tj}$, where $t = \{ control, A, B, C\}$ ...
0
votes
1answer
45 views

jointModelBayes output

Consider the following example from a workshop by Dimitris Rizopoulos workshop. We have the following joint model: \begin{equation} \begin{aligned} y_i(t) &= m_i(t) + \epsilon_i(t) \\ &= \...
2
votes
0answers
30 views

'pspline ' or 'rms' in a Cox model?

I am quite new in the spline subject and I have a question! I am using a Cox model and I was afraid that some of the variables included in the model have a non-linear effect on survival. So I tested ...
2
votes
1answer
71 views

Interpret survival curve for multiple-event Cox proportional hazard model

I am using the bladder2 dataset, which is setup in "conditional" long format: ...
0
votes
0answers
10 views

Difference in results obtained by FGR command and riskRegression command with “prop” link in the riskRegression package for competing risk regression

I was applying competing risk regression for a dataset with 486 individuals. I was using the FGR command and riskRegression command with "prop" link from the riskRegression package. The output should ...
0
votes
0answers
22 views

Survival analysis for right-truncated data with time-dependent variables

I would like to fit a parametric (exponential, log-logistic, Weibull) or semi-parametric (Cox) duration model with time-dependent covariates. My data has one specificity: it is right-truncated (and ...
0
votes
0answers
16 views

Definition of 'Individuals at Risk $Y_i$' for Left-Truncated Right-Censored Data

In 'Survival Analysis' by Klein and Moeschberger, the authors describe estimators for survival function under left-truncated and right-censored data (section 4.6, 2nd ed). Essentially, they re-use ...
0
votes
0answers
36 views

Post-hoc test for survival analysis

How can I do a post-hoc test for survival analysis to reveal which groups differ significantly? I have four groups (with 40 individuals of each) treatened by different chemicals. All of the ...
1
vote
0answers
52 views

Propensity Score Matching with Cox Regression

I am conducting a survival analysis with a Cox regression whereby the outcome variable (promotion to a senior role) is either 0 or 1. I am particulalry interested in the hazard rate (i.e., the 'hazard'...
1
vote
1answer
48 views

Variance of a random variable $X$ as a function of the survival function $S(x)$

Suppose $X$ is a nonnegative and continuous random variable with a survival function $S(x)$. Show that $$\mathsf{Var}(X)=2\int_0^\infty tS(t) \, dt-\left( \int_0^\infty S(t) \, dt\right)^2$$ ...
0
votes
1answer
19 views

Inverse probability weighted Kaplan-Meier for left truncated data

Is there any R implementation of inverse probability weighted Kaplan-Meier estimator for left truncated and right censored data? I found only implementation without left truncation in IPWsurvival ...
1
vote
1answer
60 views

Assessing Continuous Predictor with HR in Cox Model

I would like to recreate the following figure The authors state this about the figure: "Multivariate Cox regression models witha cubic natural spline analysis were used to determine the potential ...
2
votes
0answers
24 views

Time Series/Longitudinal Survival Analysis in R- is this possible?

Wondering if it possible to incorporate time series/longitudinal data into a survival analysis. I have data that represents different cases over a span of 5 years, with the same data gathered during ...
0
votes
3answers
32 views

What kind of model (consists of sequential and non sequential data) to predict failure in devices?

I have a data set of events for each device(sensor) ...
0
votes
0answers
21 views

Interpreting the calibration plot from calibrate.cph function (RMS)

I'm relatively new to survival analysis and R in general so apologies in advance if this is an obvious question. I've been running a few analyses on the RMS package in R looking at survival data and ...
1
vote
0answers
67 views

Restricted Mean Survival Time vs Hazard Ratio - How to describe the differences?

I came across this article which discusses some modifications to a traditional clinical trial monitoring setting where a time-to-event outcome is described in terms of the restricted mean survival ...
0
votes
0answers
31 views

Kaplan Meier for Annual Survival with Staggered Entry

I am carrying out survival analysis for two populations of mammals. The data available is GPS collar data: date collared, date of death or date of end of study. I am using the non-parametric Kaplan ...
0
votes
1answer
30 views

Transformations in a Cox Model

I am standardizing all my continuous covariates (and log transforming them to minimize undue influence). However I would like to express the change in the log hazard per 10 year change for my ...
0
votes
0answers
7 views

Specifying a multi-state model with unobservable terminal state

Suppose there is a multi-state process with three states, listed below and labelled as terminal/non-terminal and observable/unobservable: Initializing: non-terminal observable Active: non-terminal ...