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From | Steve Samuels <sjsamuels@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: competing risk |
Date | Wed, 7 Jul 2010 15:09:11 -0400 |
Rosetta- Welcome to Statalist! See Chapter 9, especially Section 9.3, of Stephen Jenkins's wonderful book "Survival Analysis" at http://www.iser.essex.ac.uk/files/teaching/stephenj/ec968/pdfs/ec968lnotesv6.pdf and his lesson 8 on setting up the analysis with Stata at http://www.iser.essex.ac.uk/survival-analysis You don't really have discrete survival times, you have "interval censored" or grouped times To quote Stephen (Lesson 8): "If one needs to use a discrete time model because one has interval-censored data (continuous survival times are available only in grouped form), then modelling is rather complex, and one needs special programs to estimate the models" There is an exception, I think: if you have no (or almost no) loss-to-follow up within intervals, then you can use the "multinomial logit" model that Stephen describes-just censor those "lost" individuals at the start of the interval. Questions about data with this structure (probably the same data set!) come up from time to time here. I always wonder why these surveys did not ask about dates of transitions prior to interview, even on a subsample; that would greatly enhance the usefulness of the data. Also, the questions always assume implicitly that nobody changed state twice in an interval. (e.g. unemployed--> open-ended -> fixed term). Good luck! Steve Steven Samuels sjsamuels@gmail.com 18 Cantine's Island Saugerties NY 12477 USA Voice: 845-246-0774 Fax: 206-202-4783 On Wed, Jul 7, 2010 at 6:02 AM, <lombardo@unical.it> wrote: > Dear all, > > I am running a survival analysis with discrete time data using a stock sample > (1750 individuals followed up one, three and five years after graduation). > The period at risk of being employed may ends in two competing events, namely > fixed term and open ended contracts. > I am new in using Stata. Could anyone please advise me how to deal with > competing risk in a discrete time setting? > > In a single risk model I have already organized the data so that there is one > row per person per each time at risk of being employed in a fixed or open ended > contract. > > Thank you for your attention, > > Rosetta > > * * 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/