Re: Canadian doctors coming to the US

From: George Conklin (nilknoc_at_earthlink.net)
Date: 09/05/04 

Date: Sun, 05 Sep 2004 12:10:26 GMT

"Herman Rubin" <hrubin@odds.stat.purdue.edu> wrote in message
news:chdf57$3dts@odds.stat.purdue.edu...
> In article <1Lp_c.5860$Vl5.3838@newsread2.news.atl.earthlink.net>,
> George Conklin <nilknoc@earthlink.net> wrote:
>
> >"Herman Rubin" <hrubin@odds.stat.purdue.edu> wrote in message
> >news:chd8ce$4e60@odds.stat.purdue.edu...
> >> In article <I2KZc.1615$Vl5.1292@newsread2.news.atl.earthlink.net>,
> >> George Conklin <nilknoc@earthlink.net> wrote:
>
> >> >"Herman Rubin" <hrubin@odds.stat.purdue.edu> wrote in message
> >> >news:ch7bd2$4eqk@odds.stat.purdue.edu...
> >> >> In article <mqEYc.4785$JT3.18@newsread3.news.atl.earthlink.net>,
> >> >> George Conklin <nilknoc@earthlink.net> wrote:
>
> >> >> >"Orac" <orac@mac.com> wrote in message
> >> >> >news:orac-EF355F.16333529082004@news4-ge1.srv.hcvlny.cv.net...
> >> >> >> In article <cgt8fn$22fi@odds.stat.purdue.edu>,
> >> >> >> hrubin@odds.stat.purdue.edu (Herman Rubin) wrote:
>
> >> >> >> > In article
> ><orac-A727DC.21270928082004@news4-ge1.srv.hcvlny.cv.net>,
> >> >> >> > Orac <orac@mac.com> wrote:
> >> >> >> > >In article <cgra53$4a0m@odds.stat.purdue.edu>,
> >> >> >> > > hrubin@odds.stat.purdue.edu (Herman Rubin) wrote:
>
> >> >> >> > >> In article
> ><41309b16$0$18253$79c14f64@nan-newsreader-05.noos.net>,
> >> >> >> > >> Lictor <ghostmlNOSPAM-REMOVE@online.fr> wrote:
>
> ....................
>
> >> >> > Herman denies that the usual test of statistical significance is
a
> >vaid
> >> >> >test of how effective medicine is. Thus anything the government
posts
> >> >would
> >> >> >automatically be invalid in his mind. I have never really
understood
> >why
> >> >he
> >> >> >insists that only Bayesian analysis be used, since he has never
shown
> >> >that
> >> >> >the results would be changed if you change the test. Anyway......
>
> >> >> A test of statistical significance tests whether the
> >> >> observations would be "sufficiently unlikely" if the
> >> >> null hypothesis is EXACTLY true, and NOTHING else.
>
>
> >> > Based on this comment, we could never do any medical research since
> >all
> >> >variables cannot be controlled.
>
> >> This is NOT what I said. One can do research with NO
> >> variables controlled; this is what happens in astronomy,
> >> meteorology, and economics, for example. To a large
> >> extent, it is what is done in ecology and geology. We
> >> need to use these techniques in biology (it is, to a
> >> small extent) and medicine.
>
>
> > In UK, for example, social class remains a very strong predictor of
> >health, even with nationalized health care. It is in the USA, with
> >free-enterprise medicine. It is a crime not to control for the social
> >variables (see below for stress). By the way, people high in social
class
> >have LESS stress, despite their complaints. The same is true in the
animal
> >world.
>
> So what does that prove? Stress can be of various kinds, and
> not all kinds are the same. And are people of higher social
> class genetically the same as those in lower classes? If you
> think this must be the case, you do not understand probability.
>

  So now you are saying that the rich have better genetics?

> >> > Having said that, self-selection, social class and a whole lot of
> >other
> >> >variables have fouled medical findings now for many years. They also
> >ignore
> >> >things like stress, since it is not something a BENCH scientist does.
>
> >> I have seen studies taking into account stress.
>
> > Some do. But my comment came from the latest cross-national heart
study.
> >The investigators stated what I said, but were very surprised that stress
> >was I think #3 in predicting heart attacks. We sure do know that stress
> >works in animal models.
>
> Stress is different in humans.
>

   Actually it is not.

> >> >> It does not take into account how effective the
> >> >> procedure is under the alternatives, nor the magnitude
> >> >> of the effect under the null, and hence does not balance
> >> >> the various components of risk. If 50% of the people
> >> >> exposed to a disease without treatment died, and 51%
> >> >> of 1,000,000 people given a treatment survived, this
> >> >> would be HIGHLY significant.
>
> >> > So? People would see from the figures what the effect was and the
risk
> >> >too.
>
> >> One can see this from the FULL figures, but NOT from the
> >> significance levels. It does take calculation; the
> >> original problem from which the above extremization was
> >> made was 3 out of 3 versus 7 out of 8. The results were
> >> approximately that if treatments of this type, if they
> >> worked, worked more than 90% of the time, take the 3 out of
> >> 3, else the 7 out of 8. The prior information, usually
> >> involving lots of subjectivity, MUST be used. Even in
> >> science, statistical theory shows that objectivity is not
> >> even desirable, in that there are better non-objective
> >> procedures than the best objective ones.
>
> > A very unclear statement Herman. I saw one study which claimed
'massively
> >significant' results when the advantage was 3 months in 9 years. Is that
> >what you mean? Significant but unimportant at the individual level?
(I'm
> >trying Herman.....)
>
> This is exactly what I mean. Such a result can be massively
> statistically significant; statistical significance does not
> in any way measure the strength of the effect. It merely
> measures how odd the effect would be if nothing was happening.
>

  ok

> >> >If there was a new
> >> >> treatment given to 4, and they all survived, this
> >> >> would not meet the customary significance level.
> >> >> Which treatment would YOU choose?
>
> >> > False choice too Herman. Today we are wondering if common
treatments
> >> >might make things worse, like HRT.
>
> >> And for complications like the ones occurring with HRT,
> >> it can take years to accumulate enough data. What do
> >> you do in the many years for this to happen?
>
> > Why should it? If self-selection were controlled for from the start,
we
> >would not have subjected women to years of harm. My wife asked her
> >cardiologist about the HRT studies...and she (the cardiologist) used to
do
> >family medicine too. When women really asked her, she told them NO to
HRT,
> >but other physicians (mostly ob/gyns) were pushing it.
>
> How are you going to control for self-selection from the
> start? It can only be controlled for in clinical trials,
> and even there, not everything can be controlled. The
> studies which found bad effects from HRT were not free
> from self-selection, either.
>

    They were better controlled than any other study.

> >> In medicine, we are concerned with decision making under
> >> uncertainty. We have to balance the components of risk;
> >> this is prior Bayesian behavior. One way to do it is
> >> to look at the posterior distributions, but it is not
> >> always possible to reasonably approximate this, even
> >> when one can approximate prior Bayes risk well.
>
> > No technique of analysis will overcome self-selection Herman. Crap
in,
> >crap out.
>
> If you include the variables which produce the self-selection,
> analysis can handle it; it will not be the simple analysis
> taught in statistical methods courses, and will require
> careful use of computers. Anyhow, something has to be done,
> and at least in principle, Bayesian analysis can handle such
> things as self-selection by including them. In practice, the
> models have been too difficult so far, with the worst part
> being input from physicians.
>

    So far good controls don't seem to be part of the litereature.

Relevant Pages

  • Re: Canadian doctors coming to the US
    ... >> In UK, for example, social class remains a very strong predictor of ... even with nationalized health care. ... >>have LESS stress, despite their complaints. ... > How are you going to control for self-selection from the ...
    (sci.med.cardiology)
  • Re: Canadian doctors coming to the US
    ... >> In UK, for example, social class remains a very strong predictor of ... even with nationalized health care. ... >>have LESS stress, despite their complaints. ... > How are you going to control for self-selection from the ...
    (sci.med)
  • Re: Canadian doctors coming to the US
    ... >have LESS stress, despite their complaints. ... How are you going to control for self-selection from the ... I do not claim that these views are those of the Statistics Department or of Purdue University. ...
    (sci.med.cardiology)
  • Re: Canadian doctors coming to the US
    ... >have LESS stress, despite their complaints. ... How are you going to control for self-selection from the ... I do not claim that these views are those of the Statistics Department or of Purdue University. ...
    (sci.med.nutrition)
  • Re: Canadian doctors coming to the US
    ... >have LESS stress, despite their complaints. ... How are you going to control for self-selection from the ... I do not claim that these views are those of the Statistics Department or of Purdue University. ...
    (sci.med)