cox proportional hazards

  1. R

    interpreting cox proportional test results

    Hi, I have attached an image of testing some variables using the cox proportional hazards test in R. Based on the explanation provided in this link https://www.r-bloggers.com/cox-model-assumptions/ it seems to suggest that based on the p-values, that the proportional hazards assumption holds...
  2. S

    obtaining the AUROC in a test (subset) with time-dependent (survival) ROC from Cox model

    I have survival times and fixed baseline values of biomarkers and risk factors ( I actually have them measured longitudinally but want to deal with the baseline values first). I'd like to (ideally using SAS/PHREG) estimate my Cox PH model with the baseline variables in a (2/3 of data) training...
  3. P

    Should IRRs and HRs always be equal?

    I am running an analysis in a large population registry where individuals enter and leave the dataset at different time points. When i estimated the IRR between two distinct groups and a health outcome, and then a HR, I am finding a small difference (IRR 2.18, HR 2.01). Shouldn't they have...
  4. S

    a logarithm transform of a predictor fixed proportional hazards in Cox model - how can that be ??

    0 down vote favorite I have survival data to which I am fitting a Cox model with a continuous predictor. The cumulative martingale residual method (supremum test) of Lin, Wei and Ying...
  5. D

    Correlated variables in Cox model - which one is best

    Hi there, I am building a Cox model. I have two variables that are different measures of the same thing and they are therefore correlated with each other. Both variables are strongly associated with survival. My understanding is that it is not ideal to place correlated variables in the same...