Osterholm warns about pandemic

[gsgs]

Re: Osterholm warns about pandemic

that's OK. I hope you don't mind if I debate with others.
(You wrote earlier:
"We are very interested in your ideas on probabilites ...")

 

[sharon sanders]

Re: Osterholm warns about pandemic

Yes - I like discussing anything mathematical, but to encourage people not to prepare because of some inaccurate or non-existant probability calculation is reckless.

 

[gsgs]

Re: Osterholm warns about pandemic

so, now the probability of a pandemic is "nonexisting" ?
I never heard about nonexisting probabilities in any context.
This could make an interesting paradoxon, when some future
events had existing probabilites and some others
had nonexisting probabilities.
However, probability estimates are subjective and as such
they exist at the very moment where the subject in question
specifies it to us. Well, they exist before that, but then
we will see it.
And this has been done, although not often enough IMO.
So these probabilities do "exist".

Can such an estimate be "inaccurate" ? Well, maybe when someone
specifies a range for his probability estimate rather than a number.
But then a range would not be called a probability estimate.
Instead of saying 40%-50% you could as well say : 45% .
That's a well-defined real number and it is "accurate".
It could be possible or even likely that the subjective estimate would
change when the person rethinks the issue - but that's another matter.
If this is meant with "inaccurate", then OK, an estimate for the
probability of a pandemic -say in the next 3 years- would be
"inaccurate" in this sense. How inaccurate ? We could measure
this, when we have enough estimates by enough experts.
We would also find out, whether there is some "trend" or "meaning"
in the estimates or whether it's complete guesswork like e.g.
estimating the outcome of a 3rd class football match between
two teams which you never heard about.

But then it would also be meaningless and misleading and dishonest
to make any public statement about that football-match like
"team A has good chances because my name happens to begin with A"
or such.
But inexact statements about the likelyhood of a pandemics and warnings
are being made by the experts. That proves that they think, they have
a meaningful estimate which is not complete guesswork.
Yet they don't want to specify that estimate and prefer to leave
us in the dark. That's unethical.
They could tell us, that they are uncertain about the estimate and that
the estimate might change later when they rethink the matter,
but they _should_ give us a number.
And this number should still be better than our own estimate,
since we are not experts.

Having such numbers will provoke others to give their numbers too.
It will provoke discussion about which numbers are more reasonable.
Gamblers and betters and traders will join to express their feelings
about the estimates which could also be useful since many people,
even experts have no good "feeling" about likelyhoods and probabilities,
while OTOH the gamblers have no feeling about the virological
expertise.
So, I'd hope for a useful discussion about the pandemic probability
which will lead politicians and individuals to finally base their
preparations and plannings upon.

You can underprep, but you can also overprep. Let's not base this decision
on political or private considerations, let's make it more objective
and scientificially profound by expert estimates.
When they differ, then we'll take the mean or the median.

 

[sharon sanders]

Re: Osterholm warns about pandemic

Yes - I like discussing anything mathematical, but to encourage people not to prepare because of some inaccurate or non-existant probability calculation is reckless.

I said probability calculation.........

 

[Marcie]

Re: Osterholm warns about pandemic

Florida1, after reading gsgs's last post, I don't think there is much reason to worry that he will influence any rational person to not prepare. To continue to debate this with gsgs is to "cast pearls before swine" (forgive me, gsgs, I do not think you are a pig). IMHO, sometimes people are so fearful of even the idea that the worst-case scenario could come to pass that their mind will come up with any rationalization for the case that it won't happen. Take care, gsgs.

 

[gsgs]

Re: Osterholm warns about pandemic

sorry about missing the calculation.
You wrote: "it is impossible" "with any accuracy" earlier, I had this in mind.

Well, I didn't announce discussion about some calculations
just subjective estimates.
It makes sense however to split the problem into subproblems
and check the estimates by some calculations.
E.g. when you think H5N1 will go pandemic in the next 5 years
with 50% probability and each year has same likelyhood then you can't
very well make it 20% for the first year ;-)

BTW. this is somehow surprising but I can make a good statistics that it's the females who usually oppose this "probability-estimates"-thing.
Very significant ! This could make another interesting study...

 

[sharon sanders]

Re: Osterholm warns about pandemic

"BTW. this is somehow surprising but I can make a good statistics that it's the females who usually oppose this "probability-estimates"-thing.
Very significant ! This could make another interesting study..."

Typical. When losing an argument, change the subject.

I have been insulted by the best. You are an amateur in this field.

I am proud to be a female.

:yinyang:

 

[Niko]

Re: Osterholm warns about pandemic

gsgs,

I am curious...If you got your wish - all "experts" that you respect came together and came up with a % probability of a pandemic in whatever time period. How would your behavior change? What effect would it or should it have on the preparations by individuals, communities, local and national governments, and on the international level?

What % would make you walk away from all this flu talk and go on with your life without concern for a pandemic or any disaster for that matter?

 

[gsgs]

Re: Osterholm warns about pandemic

>gsgs,
>
>I am curious...If you got your wish - all "experts" that you respect came
>together and came up with a % probability of a pandemic in whatever time
>period. How would your behavior change? What effect would it or should it
>have on the preparations by individuals, communities, local and national
>governments, and on the international level?
>
>What % would make you walk away from all this flu talk and go on with your
>life without concern for a pandemic or any disaster for that matter?

I could refer you to my answer in other threads
or maybe I should make a faq...
Well, it's not primarily for me, of course, but for the politicians
to decide how much to spend for antivirals vaccines, preparation,
WHO. And for us all to convince friends and local politicians.
It's just much more convincing when there had been quite a debate
among experts and they finally agreed on some number than
one Webster or Osterholm saying something and then others disagree.

Also, I usually ask for both, a probability estimate for a pandemic
and an expectation value for the number of deaths, both within
-say- 5 years.
OK, when my personal probability to die from an accident or from normal
flu were larger than to die from panflu then I wouldn't care
for myself about panflu-preparation.
If a pandemic were certain this year but with 99% not worse than 1957
then I wouldn't care a lot. I would still prep a bit and not go out
so much but not spend time here in forums.
If a 1918-like pandemic were >50% this year, then I would probably
relocate. (Except people here were finally doing something...)

 

[Niko]

Re: Osterholm warns about pandemic

I could refer you to my answer in other threads
or maybe I should make a faq...

Thank you for your detailed response. I thought it important you to clarify in this thread. Although you may have expressed your opinions other places, it was relevant to your posts on this thread and also for the benefit of those who may not have been privy to your other posts here and elsewhere

 

[LeaSoul]

Re: Osterholm warns about pandemic

:surrender: This has been a fascinating thread to read.
Many emotions, which is just right to get others thinking. As long as everyone stays civil and regardless of opinions treats each other with respect.
With that said, since I am new to FT I'll keep my opinions to a minimum for now.

 

[AlaskaDenise]

Re: Osterholm warns about pandemic

Perhaps another method to explain the "odds" of a pandemic is to look at history PRIOR to 1918. If we go way back to the first assumed influenza pandemic - 412 - and some probably earlier, an ordinary person can see that they occur with some regularity.

Then, if we take our current "preparedness" - limited antivirals, no VAX, hospitals without much surge capacity, limited PPEs, etc. - and apply our situation to known past pandemics - how would it have changed them?

When you hear that entire towns in Spain were wiped out, how would "modern medicine" change that situation?

I suspect the past pandemics may not have been quite as lethal, but there still would be many deaths. We always compare to 1918, while earlier pandemic were far deadlier (in %, not absolute numbers).

So our "range" of probability is not only 1918, but slightly better than the earlier more lethal pandemics. It's not an exact number, but an "historical reinactment" that may provide a yardstick.

.

 

[LeaSoul]

Re: Osterholm warns about pandemic

But inexact statements about the likelyhood of a pandemics and warnings
are being made by the experts. That proves that they think, they have
a meaningful estimate which is not complete guesswork.
Yet they don't want to specify that estimate and prefer to leave
us in the dark. That's unethical.
They could tell us, that they are uncertain about the estimate and that
the estimate might change later when they rethink the matter,
but they _should_ give us a number.
And this number should still be better than our own estimate,
since we are not experts.

Having such numbers will provoke others to give their numbers too.
It will provoke discussion about which numbers are more reasonable.
Gamblers and betters and traders will join to express their feelings
about the estimates which could also be useful since many people,
even experts have no good "feeling" about likelyhoods and probabilities,
while OTOH the gamblers have no feeling about the virological
expertise.
So, I'd hope for a useful discussion about the pandemic probability
which will lead politicians and individuals to finally base their
preparations and plannings upon.

No doubt the "experts" do have a valid estimate but they're not going to tell anyone. Why? People will panic. Their numbers will provoke untold stupidity in otherwise docile human beings. In addition, fear is a great controller in our world. Fear has been used successfully throughout history to control the masses.
Prepare for the short term (3 to 4 months) and the long term (4 months to 3 years). If it isn't the pandemic that bags the collective behind it will be some other event.

 

[sharon sanders]

Trying to Forecast Mother Nature..........

Trying to Forecast Mother Nature..........

Application of Evidence Theory to Quantify Uncertainty in Forecast of Hurricane Path
Svetlana V. Poroseva, Florida State University, Tallahassee, FL; and J. Letschert and M. Y. Hussaini


Results of any computations are of practical use only if information on their accuracy is also available. It is especially true in forecasting hurricane paths where the prediction accuracy is of vital importance. Yet, most current forecasts lack such information. The present study investigates the potential of using evidence theory [1] to provide a quantitative assessment of forecast accuracy and to develop a reliable procedure for combining different forecasts to produce the best possible prediction.


Uncertainties and errors in computational results on hurricane forecasts originate from various sources -- failure of a climate model to describe correctly the atmospheric physics and the interaction between the atmosphere and the ocean; stochastic nature of model parameters; errors associated with the discretization and algorithmic approximations, to mention just a few. Depending on the origin, the uncertainties can be categorized as aleatory (random, stochastic) and epistemic (due to lack of knowledge) uncertainties. In reality, the interaction among the uncertainty sources and the lack of knowledge make it generally impossible to identify and separate the sources to quantify their individual contribution to the total forecast uncertainty. In the present study, we define an appropriate measure to quantify the total uncertainty in forecasts of the given climate model, computer code and grid. Such a measure would allow one not only to compare quantitatively the performance of different climate models, but also evaluate the effectiveness of modifications introduced in a single model.


As both aleatory and epistemic uncertainties are intricately interwoven in a hurricane forecast, one needs a statistical theory that could handle them together to quantify their impact on forecasts. Whereas the probability theory could deal with the aleatory uncertainty and the possibility theory with epistemic uncertainty, the evidence theory [1] provides a systematic framework for such a study, and it is relatively well developed among other related theories. Unfortunately, there are very few practical applications [2] of evidence theory and they differ considerably from the one addressed here. Previously, we developed [3] an approach based on evidence theory to quantify uncertainty in turbulence computations. Results of testing the approach in a turbulent flow encourage us to apply similar approach to hurricane path forecasts with appropriate extension and modification.


Evidence theory provides the necessary tools not only to quantify the forecast uncertainty, but also to fuse the results of different forecasts. The idea of improving the overall credibility of hurricane path predictions by combining results of several forecasts is not new. Multimodel superensemble technique [4] is an example of the successful implementation of the idea.


However, multimodel forecasts like the single model forecasts do not provide information on the forecast accuracy. The present approach provides the quantitative assessment of the forecast accuracy and differs completely from other multimodel techniques in its mathematical foundation.
Briefly stated, the procedure involves first quantifying the uncertainty in results using each of several climate models under controlled conditions, where observation data for hurricane paths are available. Uncertainties in the spatial coordinates describing the hurricane position are quantified separately and assumed to be time dependent. This information is then combined with the results of simulations using each model to forecast a hurricane path for which observational data are not available. For each model at each instant of the forecast, we construct a grid centered on the model prediction of the hurricane position. Each grid interval in latitude and longitude directions is characterized by the degree of support (or belief) that the real hurricane position falls within the interval. The degree of support is the measure of model uncertainty. Its interval values are found during the previous step of the procedure. Then, the results from all models are fused using Dempster's rule of evidence theory to create a new prediction. The final prediction is also characterized by degrees of support. The details of the procedure will be discussed in the final paper.
The database for hurricanes of 1998-2001 in the Pacific Ocean is used to quantify uncertainty in forecasts by global models from two operational centers -- the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS) and European Centre for Medium-Range Weather Forecasts (ECMRWF). The performance of these two models is compared for each year. We also track the effectiveness of annual modifications in each model. The data for hurricanes of year 2000 are used to evaluate the approach we developed to fuse different forecasts. Observational data for three hurricanes from the South Pacific region, three hurricanes from the East Pacific region, and six hurricanes from the West Pacific region are used solely for the evaluation of the quality of predictions obtained with the new technique. The data for other hurricanes of year 2000 are used to quantify the model uncertainty during the step preceding forecasts fusing.
Authors express their gratitude to Professor T. N. Krishnamurti and Dr. V. Kumar (Department of Meteorology, Florida State University) for providing observational and model data necessary for this study.


References 1. Shafer, G., ?A Mathematical Theory of Evidence,? Princeton, NJ: Princeton University Press, 1976. 2. Oberkampf, W. L., Helton, J. C., and Sentz, K., ?Mathematical Representation of Uncertainty,? AIAA 2001-1645, 2001. 3. Poroseva, S. V., Hussaini, M. Y. & Woodruff, S. L., ?On Improving the Predictive Capability of Turbulence Models Using Evidence Theory?, AIAA-2005-1096, 2005. 4. Williford, C. E., Krishnamurti, T. N., Torres, R. C. et al., ?Real-Time Multimodel Superensemble Forecasts of Atlantic Tropical Systems of 1999,? Monthly Wetaher Rev., v. 131, 2003, pp. 1878-1894.
Extended Abstract (484K)


http://ams.confex.com/ams/Annual2006/techprogram/paper_99724.htm





I believe many experts do not commit to a probability figure for a pandemic because it is too difficult to measure accurately. They are in are a difficult situation. They are wrong if they do, and wrong if they do not.

 

[gsgs]

Re: Osterholm warns about pandemic

Snowy, I don't understand what point(s) you are trying to make (as usual).
AD, this is different, because it's a global damage. You can't prepare
for everything, you must set priorities.
AD, so ordinary persons can see that pandemics occur with some regularity but scientists cannot ? And if, which of the two groups
should be rely on ?
Which other (flu-)pandemics were far deadlier than 1918 ?
Florida,how to "measure accurately" a probability figure ? It's
an estimate, just how people estimate football games
or share-prices. Experts and others can always be wrong when writing something, but that's no reason to stop writing.
I don't know, how the hurricanes study applies to our situation.
The very first sentence is logically clearly wrong.

 

[gsgs]

Re: Osterholm warns about pandemic

here some info about the aftermath of the 1976 non-pandemic

--------------------------------------------------------------------------------------------------------------

from
Richard E. Neustadt, Ernest R.May , thinking in time , the uses
of history for decision makers (1988)

page 152

First: if someone says: "a fair chance" as before the Bay of Pigs
(or a "strong possibility" as with swine flu), or more generally,
"The Guatemalans won't let us keep our camps here," ask,
"If you were a betting man or woman, what odds would you put on that ?"
If others are present ask the same at each, and of yourself too.
Then probe the _differences_:Why ? This is tantamount to seeking
and then arguing assumptions underlying different numbers
placed on a subjective probability assessment.
We know no better way to force clarification of meanings while
exposing hidden differences.
Judging by our students, millions of Americans are either
unfamiliar with numerical notations of probability or are
uncomfortable at the idea of stating a subjective judgement
in such terms.The doctors of the swine flu case,for instance,
recoiled from it, at least outside their own ranks.
On odds of a pandemic they refused to give Ford any number
beyond " 1 to 99 percent". [12] But we have yet to find
a fellow citizen unused of placing bets and giving odds
on races or at games. So play it as a game and ask for odds
on each presumption.If the doctors or their fellow experts
hesitate we offer the suggestion of one accademic collegue
with extensive government experience: Ask instead, "When
I brief the press, with you by my side as an expert, and
I tell them the odds are X, will I be right ? No ?
Then how about Y ?" And so forth.
Once differing odds have been quoted, the question "why ?"
can follow any number of tracks.Argument may pit common sense
against common sense or analogy against analogy.
What is important is that the expert's basis for linking
"if" with "then" gets exposed in the hearing of other
experts before the lay official has to say yes or no.
A variant on giving odds is placing bets in the sense
of a challenge:"How much of your own money would you
wager that the presumed thing actually happens ?"
Hidden differences are flagged by different sums.


[12] : Richard E. Neustadt, Harvey V. Fineberg , The Epidemic That Never Was (1983)

http://www.sciforum.hu/index.php?image=speakers&content=sp_fineberg
http://en.wikipedia.org/wiki/R._E._Neustadt
http://ksgfaculty.harvard.edu/Ernest_May

------------------------------------------------------------------------------------------------------

Estimating The Odds Of A 1976 Pandemic
1.) CDC formed two panels of experts to estimate the probability of a pandemic
in 1976 result :
---- 10%-25%
---- 40%

2) the members of the Advisory Committee (March 10,1976) later said they had assigned
privately nonpublic probabilities for a 1976 pandemic of
---- 2%-20%

3) departmental and White House aides assigned to that event probabilities of
---- 20%-50%
("the higher the level, the fewer the doubts")


sources:
1) http://www.ourcivilisation.com/aids/chap3.htm
2) Alexander,May page 55

----------------------------------------------------------------------------------------------------------------

"Alexander-Questions"

from Richard E. Neustadt, Ernest R.May , thinking in time , the uses of history for decision makers (1988)


page 152 ,153


Our second test is "Alexander's question". One of us coined this term for it in another book,
and we might as well stick with the label [13].
The Alexander named is not Aristotele's pupil, the great conqueror, but merely the man who asked
the question in March 1976 at the Advisory Committee meeting that preceeded the decisions
to immunize the country against swine flu. Dr. Russell Alexander [a], a public health professor
at the University of Washington, wished to know what fresh data from anywhere, including
the Southern Hemisphere, could cause his collegues to revise or to reverse their judgement
that the country should get ready to be immunized _en masse_ starting next summer.
Mild outbreaks only ? None ? Time-frames ? Locations ? He asked but never got an answer.
In the circumstances it was the right question, we believe;pursuing it it would
have flushed out a set of deeper questions, which also did not get asked: questions
about tradeoffs between side effects and flu, questions about programming and scheduling
review, questions distinguishing severety from spread, questions about stockpiling, and more.
In retrospect they all deserved a thorough airing.This they did not get. Still the right
initial question _was_ asked.We draw our term from that.
Adapting but slightly we put the emphasis on presumptions rather than conclusions, and urge
the comparable questions:What new _Knowns_ would bring you to change items _Presumed_ ?
When ? And why ? Passed around the circle, those should sharpen differences, spur debate,
and force out inferences, whether of courses or of values. The counterpart question did
not do that for Alexander.That is because the director of the CDC chairing the meeting where
Alexander asked it chose not to pursue it. We recommend hot pursuit.



[13] : Richard E. Neustadt, Harvey V. Fineberg , The Epidemic That Never Was (1983)

[a] : http://seattlepi.nwsource.com/local/261096_russobit28.html

: http://66.249.93.104/search?q=cache:F5psvPsKguIJ:www.americaabroadmedia.org/docs/Sencer%2520transcript.pdf

 

[gsgs]

Re: Osterholm warns about pandemic

see here, what Prof.Steele wrote on his blog about the subject:


http://birdflueconomics.blogspot.com/2006/07/probability-of-pandemic-when-if-ever.html

about J.Michael Steele:
http://www-stat.wharton.upenn.edu/~steele/index.html

 

[gsgs]

Re: Osterholm warns about pandemic

keep asking the experts for their probability estimates of a pandemic
and their expectation values of panflu-deaths.
Both in the next -say- 5 years.
And report the answers here !

In the aftermath of the next pandemic, what do you think will be considered the biggest mistake in pandemic preparations ?

 

[sharon sanders]

Re: Osterholm warns about pandemic

Quote by Prof. Steele speaking on the forecasting of pandemics:

"I believe that we already possess a rich enough scientific base for the probability estimation problem to be moved beyond the simple subjective probability estimates of individuals."

I disagree. The amount of mathematical modeling required to forecast the probability of a pandemic would be immense.

Some of the factors that would need equations:

avian infection in the majority of the world's geography,
endemic infection in the environment in South East Asia,
domestic bird infection in many countries,
amount of possible vectors - birds, poultry, feces, mammals, etc.
life of organism outside of the host,
genetics changes possible to virus,
human to human transmission rates,
rate of change in genetic structure of the virus,
etc. etc. etc.

In addition, it seems that many of the "experts" can not agree if recombination is a factor, or not. This makes the equations needed to calculate genetic changes flawed.

The best estimate we going to get is the cyclical nature of history and the level of concern that various experts have that this virus may become sustained human to human.

People ask me what the chances are that this virus will become pandemic and the truthful answer is that I do not know.

But it is possible - why not prepare? This preparation will be useful for the other calamities that happen on a regular basis: earthquakes, hurricanes, fires, job loss, etc.

 

[gsgs]

Re: Osterholm warns about pandemic

>Quote by Prof. Steele speaking on the forecasting of pandemics:
>
>"I believe that we already possess a rich enough scientific base
> for the probability estimation problem to be moved beyond the
> simple subjective probability estimates of individuals."
>
>I disagree. The amount of mathematical modeling required to forecast
>the probability of a pandemic would be immense.

that was an unexact "enough".."beyond" statement by Steele. No reason to
disagree. It's just a matter of interpretation.
Any collection of individual probabilities and forming the average
might already fulfill.

A complete mathematical modeling is not meant. Just -maybe-
some mathematical tools or calculations on subproblems
or similar problems to aide building the feeling for a good estimate.
Different experts will still give different estimates,
even when they are very well informed on all available data.

>Some of the factors that would need equations:
>
>avian infection in the majority of the world's geography,
>endemic infection in the environment in South East Asia,
>domestic bird infection in many countries,
>amount of possible vectors - birds, poultry, feces, mammals, etc.
>life of organism outside of the host,
>genetics changes possible to virus,
>human to human transmission rates,
>rate of change in genetic structure of the virus,
>etc. etc. etc.

yes, lots of factors. You should evaluate them all and assign
probabilities to them on paper and then calculate the overall
probability by combining the sub-probabilities.
We usually develope some feeling for this
without doing the intermediate,helpful steps on the subproblems
and different aspects.

>In addition, it seems that many of the "experts" can not agree
>if recombination is a factor, or not.

most seem to think that it is not so important

>This makes the equations needed to calculate genetic changes flawed.

estimates will vary. Take the average.

>The best estimate we going to get is the cyclical nature
>of history and the level of concern that various experts
>have that this virus may become sustained human to human.

you may formulate it this way (level of concern --> probability estimate)

>People ask me what the chances are that this virus will become
>pandemic and the truthful answer is that I do not know.

no. You are not certain, but you do know. If you had to give a number,
you would. If you had more time, you might give another number, though.
But you know more about the problem than nothing.
You would probably agree that it's >1% and <99% . That's still
something and better than "I do not know".
Your number would still probably be informative for others
despite your uncertainety.

>But it is possible - why not prepare? This preparation will be
>useful for the other calamities that happen on a regular basis:
>earthquakes, hurricanes, fires, job loss, etc.

maybe, maybe not. That's another question.
And the question is not whether to prepare or whether not to
prepare, but how much to prepare.