# survival

1. ### What if events also have factors, not only the studied subjects!!

Hello everyone... despite my a little knowledge in survival analysis and its available models.... I have the following question: What I know that Cox models offer a hazard function, with the assumption of proportionality of the hazard for different studied subjects. The frailty component...
2. ### cox regression v. kaplan-meier

hi everyone! thanks in advance for your help! i'm studying whether the presence of high v. low hormone levels (of several different hormones) affects survival - i assume that i am to use kaplan-meier to analyze the data rather than cox regression. i am also not sure how to get SPSS to...
3. ### Urgent - Kaplan-Meier plot - how to predict survival at different time points

Hi, I've conducted a kaplan-meier survival plot relating the event (death), to time (varying follow-up times around 2 years). The output has shown me a mean, and median survival time with confidence intervals. I'd like to represent my findings as "expected" survival at 1 and 5 years. How...
4. ### Cox Proportional Hazards Assumption Question

I have a dataset of cancer cases from 1997 to 2007. I am performing a Cox Model on this set of cases. However, I just realized that mortality rates and the raw number of deaths are decreasing. Does anyone have an opinion as to whether a non-constant death rate over time will violate any Cox...
5. ### Survival Analysis: Cox Proportional Hazards with 4000 indicator variables

THE SITUATION: I am preparing a 420,008 observation Cox Proportional Hazards Regression model with 4001 indicator variables. The 4001st indicator is my baseline. I am using STATA to accomplish this task, but STATA/IC's maximum number of indicators it can generate is set at 2000. Further, the...
6. ### Age as time scale

I am generally a SAS user, I had a general question concerning how to fit survival models using age as the time scale within R. Would this fit be appropriate and also control for the left-truncated nature of the data? I know in SAS you need to specify a specific option. I was just...