Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: -sts gen [newvar] = h- : why do I get monotonous (increasing) hazards?


From   László Sándor <sandorl@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: -sts gen [newvar] = h- : why do I get monotonous (increasing) hazards?
Date   Sun, 11 Jul 2010 16:15:49 +0200

Thanks, Steve.

I thought this was what I was doing. -sts [graph]- shows a smoothed
density of the deltaH over time. I guess delthaH *is* what I get from
-sts gen-. So I must be plotting it the wrong way. Could you help me
have a "step function" (in _t, I guessed) instead of -sts [graph],
hazard- exactly as a histogram relates to a kernel density estimate?

Thanks again,

Laszlo

On Sun, Jul 11, 2010 at 4:10 PM, Steve Samuels <sjsamuels@gmail.com> wrote:
>
> -sts gen-  does not produce estimates of the hazard function.
>
> From the help:
>
> " h produces the estimated hazard component deltaH_j = H(t_j) -
> H(t_(j-1)), where t_j is the current failure time and t_(j-1) is the
> previous one. This is mainly a utility function used to calculate the
> estimated cumulative hazard H(t_j), yet you can estimate the hazard
> via a kernel smooth of the deltaH_j..."
>
>
> Steve
>
> Steven Samuels
> sjsamuels@gmail.com
> 18 Cantine's Island
> Saugerties NY 12477
> USA
> Voice: 845-246-0774
> Fax:    206-202-4783
>
>
> 2010/7/11 László Sándor <sandorl@gmail.com>:
> > Ahh, sorry, I forgot the code, though it is nothing surprising, I think:
> >
> > sts if clean == 1, hazard by(reviewerrole)  tmax(60) ///
> >        title("Completion hazards by treatment group") ///
> >        xline(45) xline(28) xline(21, lc(green)) xline(38, lc(green))
> > graph export refhazard.pdf, replace
> >
> > cap drop hazard
> > sts generate hazard = h, by(reviewerrole)
> >
> > 2010/7/11 László Sándor <sandorl@gmail.com>:
> >> Hi,
> >>
> >> I wanted to use -sts gen- to produce my own variant of the hazard
> >> graphs that -sts [graph]- produces. I am puzzled by what I get. That
> >> graph shows (very plausibly for my data) varying hazard, sometimes
> >> rising, sometimes falling, for all the four groups I plot it
> >> separately (using the option -by-). When I used the -sts gen [newvar]
> >> = h- command, I get hazards monotonously increasing in "time" (_t
> >> after stset).
> >>
> >> What am I doing wrong?
> >>
> >> I paste you the commands I use, but they are not functional w/o my
> >> data, I know. In any case, it would very useful if you could help me
> >> reproduce the -sts graph ..., hazard- graphs using the output of -sts
> >> gen ...=h-. (FYI, my goal is to use rough step function from -graph
> >> bar- instead of smooth kernel density estimate.)
> >>
> >> Thank you!
> >>
> >> Laszlo
> >> *
> >> *   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/
> >>
> >
> > *
> > *   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/
> >
>
>
>
> --
>
> *
> *   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/

*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index