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From |
"Kieran McCaul" <kamccaul@meddent.uwa.edu.au> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
RE: st: RE: stset and stsum problem |

Date |
Tue, 18 Mar 2008 08:58:20 +0900 |

I'm still not exactly clear what you've done, but I think that you have miss-specified the survival time. If you look at the example data that you provided, for ID=1 there are two records the first with duration 12 months and the second with duration 17 months. Both of these have been calculated by subtracting firstyearentry from yearexit. The stset command will therefore interpret this as a total survival of 29 months for ID=1. This is not the case, the total survival is only 17 months. The survival duration should be calculated by subtracting yearentry from yearexit. By the "dot in stsum", I assume you mean the missing 50th and 75th percentiles of the survival distribution. If the overall survival is better than 50%, then there will be no 50th or 75th percentile, so they will be missing. -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of ncdcta00@uniroma2.it Sent: Monday, 17 March 2008 5:49 PM To: statalist@hsphsun2.harvard.edu Subject: Re: st: RE: stset and stsum problem Dear Kieran, my problem is that I have dot in stsum when use all observations and streg have strange coefficients thanks a lot Quoting Kieran McCaul <kamccaul@meddent.uwa.edu.au>: > What exactly is the problem? > > ______________________________________________ > Kieran McCaul MPH PhD > WA Centre for Health & Ageing (M573) > University of Western Australia > Level 6, Ainslie House > 48 Murray St > Perth 6000 > Phone: (08) 9224-2140 > Phone: -61-8-9224-2140 > email: kamccaul@meddent.uwa.edu.au > http://myprofile.cos.com/mccaul > _______________________________________________ > > -----Original Message----- > From: owner-statalist@hsphsun2.harvard.edu > [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of > ncdcta00@uniroma2.it > Sent: Sunday, 16 March 2008 3:44 AM > To: statalist@hsphsun2.harvard.edu > Subject: st: stset and stsum problem > > Dear statlist, > I have tried to set my data for a survival analysis, but I have a > problem when use stset and put all the observations censored. > My dataset is this: > id firstyearentry yearentry yearexit duration canvi > 1 3/2001 3/2001 3/2002 12 0 > 1 3/2001 4/2002 9/2002 17 1 > 2 8/2002 8/2002 11/2002 3 0 > 2 8/2002 12/2002 5/2003 9 0 > 3 ..... > ... > > The command that I use is: > stset dur, f(canvi==1) id(id) > If I put all the observation censored and not with stsum I have this: > stsum; > > failure _d: canvi > analysis time _t: dur > id: id > > | incidence no. of |------ Survival > time -----| > | time at risk rate subjects 25% 50% > 75% > ---------+-------------------------------------------------------------- > ------- > total | 10661543 .0002694 34301 1025 . > . > > > If I take only the observation with failure ==1 I have this: > > failure _d: canvi > analysis time _t: dur > id: id > > | incidence no. of |------ Survival > time -----| > | time at risk rate subjects 25% 50% > 75% > ---------+-------------------------------------------------------------- > ------- > total | 960671 .0030687 2951 131 283 > 469 > > Someone can help me to understand where is the error? > Thanks in advance. > best, > catia > > > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > > > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > Catia Nicodemo * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**Re: st: coding question***From:*Maarten buis <maartenbuis@yahoo.co.uk>

**st: stset and stsum problem***From:*ncdcta00@uniroma2.it

**st: RE: stset and stsum problem***From:*"Kieran McCaul" <kamccaul@meddent.uwa.edu.au>

**Re: st: RE: stset and stsum problem***From:*ncdcta00@uniroma2.it

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