All Questions
Tagged with cox-model regression
213 questions
5
votes
0
answers
310
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Interval Censored Survival Analysis [duplicate]
I am conducting a study on neurological diseased patients. I am looking into possible factors related to time-to-dementia. Costs associated with neurological testing allow us to assess all patients in ...
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5
votes
1
answer
5k
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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 <...
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2
votes
1
answer
1k
views
Simulation Analysis of a Cox Survival Model with Change Point.
I wish to simulate survival data for the following probabilistic model which will be analyzed using a Cox model:
An exposure $X$ is modeled as binary having $X \sim_{iid} \mbox{Bernoulli}(p)$ where $...
- 401
1
vote
2
answers
478
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Should I keep the interaction term?
I am doing research on mortality. I am running Cox regression and I am adjusting for 40 variables which are proven in the literature to be related with mortality. My main exposure is X. In my final ...
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1
vote
1
answer
2k
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Backward selection in a Cox regression model
My goal is to fit a cox regression model in SAS, for which I use the PROC PHREG statement. As I am still new to regression methods, I would appreciate a little of ...
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2
votes
1
answer
922
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Which model should I use if I get different models using forward and backward Cox regression?
I am running an Cox regression with my data. In my final model I had four potential predictors and did first a forward (Wald method) Cox regression and then for validation of my model a backward (Wald ...
9
votes
3
answers
17k
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Computing c-index for an external validation of a Cox PH model with R
First off, I'll state that I'm aware many questions get asked about the c-index. I've searched this site and others, and I haven't found an answer for my situation. I can successfully use ...
- 927
3
votes
2
answers
713
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Interpreting Cox regression
My regression results are as follows.
Variable B exp(B)
age 0.004575 1.004586
capital 0.2250 1.2524
year -0.1026 0.9024
...
- 31
56
votes
5
answers
56k
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Prediction in Cox regression
I am doing a multivariate Cox regression, I have my significant independent variables and beta values. The model fits to my data very well.
Now, I would like to use my model and predict the survival ...
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4
votes
0
answers
736
views
How are absolute risks estimated by the Cox model? [duplicate]
According to my modest understanding, the Cox model is all about estimating hazard ratios, relative measures of risk. However, it is possible (in R using e.g. the packages ...
- 3,814
20
votes
3
answers
19k
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Time dependent coefficients in R - how to do it?
Update: Sorry for another update but I've found some possible solutions with fractional polynomials and the competing risk-package that I need some help with.
The problem
I can't find an easy way to ...
- 5,996
8
votes
2
answers
7k
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Cox model with LASSO
Rob Tibshirani propose to use lasso with Cox
regression for variable selection in his 1997 paper
"The lasso method for variable selection in the Cox
model" published in Statistics In Medicine 16:385.
...
user4254
38
votes
1
answer
14k
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Does Cox Regression have an underlying Poisson distribution?
Our small team was having a discussion and got stuck. Does anyone know whether Cox regression has an underlying Poisson distribution. We had a debate that maybe Cox regression with constant time at ...
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