Questions tagged [frailty]
The frailty tag has no summary.
61 questions
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Does a significant frailty variance weaken the evidence for non-proportional hazards compared to a Cox model with a robust estimator?
This is a follow-up question from this post:
The difference in VIF between frailty model and standard Cox model with robust estimator
In my case, I chose to use a frailty model due to high VIF in the ...
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The difference in VIF between frailty model and standard Cox model with robust estimator
I am analyzing multicenter datasets using both frailty models and standard Cox models with robust standard errors.
For each dataset, the VIF (calculated via rms::vif()) in the frailty models is very ...
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Difference between multilevel Cox models and time-varying (frailty) Cox models in patient level?
I'm analyzing multicenter survival data using R's coxme package. My data is in start-stop format after tmerge() for time-varying biomarkers, so each patient has multiple rows (one per time interval) ...
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Is the intraclass correlation (ICC) applicable to survival data?
I was asked to give a talk on the basics of clustered/longitudinal data with reference to sample size calcs - and therefore will discuss things like the ICC, design effect and actual sample size vs ...
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Issues Fitting Interval-Censored Shared Frailty Model with frailtyPenal() from frailtypack
I’m attempting to fit a shared frailty model using frailtyPenal() from the frailtypack package. My data is interval-censored, with follow-up visits every 6 months over a 3-year period. I assume that ...
- 395
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Interval censored time to event data with frailty term
I have data collected over a 3 year period 6 month intervals aiming to estimate the time to a specific event. We assume that the data is interval censored, meaning that the event occurence is known to ...
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Applying one frailty value to all observations in mixed effects cox regression and then recalculating the survival probability
I want to test the difference in survival probabilities for if every observation in my dataset was part of the frailty group with the worst or best frailty value. I want to calculate the survival ...
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How is a frailty model in survival analysis expressed
In some sources 1 one reads that the frailty model expands on the cox proportional hazards model
$$h_i(t|x_i)=h_0(t)\exp(\beta x_i)$$
by adding a frailty term $z$ like so
$$h_i(t|x_i,z_i)=h_0(t)\exp(\...
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1
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How to interpret the Wald Chi-square test for the frailty term in a mixed-effects Cox survival model?
Background
I'm fitting a Cox model to assess the relationship between treatment (binary) and time-to-event (event is also binary) while also controlling for 3 or 4 covariates. Because I want to ...
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Cox PH controlling for multiple events
I'm working on a cox proportional hazard analysis in R using the survival package.
I´m analysing covariate effects on fish movement within a study area. The study area is divided into two zones ("...
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107
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Survival model for longitudinal data with overlapping exposures
I have a dataset with info on patient exposures (drug 1 / drug 2) and outcomes (hospitalisation / death) over ten years. All patients were prescribed drug 1 on and off over the period (inclusion ...
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Correct pooling of shared frailty models fitted on multiply imputed datasets
I'm wondering whether the pool() function from R's mice package correctly pools shared frailty models fitted on multiply imputed ...
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339
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Within-cluster correlation in lognormal shared frailty models
According to Peter Austin (ref. below), in a gamma shared frailty model (i.e. a Cox regression model with cluster specific random effects which are iid logarithms of gamma distributions), the within-...
- 620
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Would you choose a joint frailty model or a multi-state model for survival analysis with recurrent events and competing risks?
I am going to analyse data with multiple recurring events and additional terminal event. The recurrent events are of the same kind, no hierarchy in them (like in the Prentice-Williams-Petersen). The ...
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Which frailty model is better for survival analysis with recurrent events and competing (teminal) risks: joint or shared?
I am going to analyse data with multiple recurring events and additional terminal event.
The recurrent events are of the same kind, no hierarchy in them (like in the Prentice-Williams-Petersen).
The ...
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