|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: eqivalent to stkerhaz for discrete time survival analysis?
Dear statalisters,
I am performing a survival analysis of attrition from the nursing
occupation (dependent variable is binary: 1 eq 'death/moved out'; 0 eq
not moved out, and the time variable is discrete and ranges from 1-13
'years sice graduation').
I have read that I should estimate a baseline hazard to describe the
form of the hazardfunction. However, I am not sure how to do this. I've
found an ado which is called stkerhaz, but it seems this command should
only be used after stcox, and I will probably be using the hshaz (model
2) or logit or cloglog. Is there a command which can help me estimate
the baseline hazard and plot the hazardfunction, or do I have to
calculate this myself? In the latter case, how do I do this?
Furthermore, I've been playing around a bit with hshaz, and the
computations/convergence take a lot of time, particularly for model 2. I
get messages from stata iteration log that the likelihood is very close
to non-concave (or something in that direction). What is the best method
to 'avoid' this long series of iterations?
Here is the syntax I wrote (please tell me if it is wrong) where :
male = man eq 1;
year1_4 = 1 to 4 years after graduation;
year5_8 = 5 to 8 years after graduation
(the omitted category is 9-13 years after graduation)
LPNR is the id-variable
movedout is the dependent variable (1= moved out, 0=not moved out)
Year is the time wariable, ranging from 1-13 years after graduation from
the nursing study program
hshaz male year1_4 year5_8 male*year1_4 male*year5_8,
id(LPNR) dead(movedout) seq(year)
Do you by the way know of a document which gives examples of estimation
techniques and interpretation of estimates for the hshaz-command?
(something similar to the chapter 7 from
http://www.iser.essex.ac.uk/iser/teaching/module-ec968 ?)
Best wishes,
Hilde
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/