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

 From László Sándor 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
> >> *
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> >>
> >
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> >
>
>
>
> --
>
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```