wu :: forums - Print Page


    
      
        wu :: forums
        (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)
      

        riddles >> general problem-solving / chatting / whatever >> An idea for an iphone app to combat the swine flu.
        
(Message started by: amichail on Apr 29^th, 2009, 8:27pm)

Title: An idea for an iphone app to combat the swine flu.
Post by amichail on Apr 29^th, 2009, 8:27pm

The idea is that you would inform the app any time you see someone who sneezes or coughs or looks sick. The app would combine this tip along with your current location.

In this way, you can still leave your house but avoid areas where sick people were seen recently.

You can make it more sophisticated by indicating what this person looks like, where this person is going, the density of people around him/her, whether he/she is indoors, etc.

Title: Re: An idea for an iphone app to combat the swine
Post by Aryabhatta on Apr 29^th, 2009, 9:51pm

Amusing...
But I don't think this will work. Most likely, all areas will be flagged and the app will be useless. Could be good for making quick cash though... :P

Title: Re: An idea for an iphone app to combat the swine
Post by Obob on Apr 30^th, 2009, 6:33am

Or you could just have an app that says, "Use common sense, practice good hygiene, and get an immune system." If you're that paranoid about it, you would have to avoid virtually all confined public places.

Said app would also be reliant on having a huge number of people using it for it to mean anything, which seems unlikely.

Title: Re: An idea for an iphone app to combat the swine
Post by Azgard on May 16^th, 2009, 8:39am

Even if you have a lot of people using the application, you are in the middle of allergy sneezon... I mean season...

Title: Re: An idea for an iphone app to combat the swine
Post by BenVitale on May 20^th, 2009, 1:39pm

Why did the world panic over this flu?

Consider the regular flu. CDC estimated that about 36,000 people died of flu-related causes each year, on average, during the 1990s in the United States.

http://www.cdc.gov/flu/about/disease/us_flu-related_deaths.htm

And, worldwide, the annual death toll from the flu is estimated to be between 250,000 and 500,000.

http://edition.cnn.com/2009/HEALTH/04/28/regular.flu/index.html

Consider the following article: The math behind estimating seasonal flu deaths. :

http://www.slate.com/id/2218367/

I haven't done stats for a long time ... could anyone please explain or restate the following:

Quote:

Suppose 52,000 people died in the first week of February 2004; 55,000 in the same week in 2005; 51,000 in 2006; and 54,000 in 2007. Suppose furthermore that the number of influenza specimens confirmed by labs was 1,000, 2,500, 500, and 2,000 in the four weeks in question. Then it certainly looks like the flu is killing people (whether directly or by opening the door to another lethal illness) at a rate of about two deaths per confirmed specimen; in a world without influenza, the death rate would be constant at 50,000 per week.

In real life, though, the numbers aren't that clean—they never are. Lots of nonflu factors push the death rate around from week to week and year to year. But a statistical technique called regression allows us to find the value of X such that the formula

[Total deaths] = [Deaths if there were no such thing as flu] + X*[number of confirmed flu cases]

matches the data as closely as possible. The rightmost term, X*[number of confirmed flu cases], is then our estimate for the number of deaths you can attribute to flu. In the example above, you'd choose [Deaths without flu] to be 50,000 and X to be 2. And if 18,000 specimens test positive for flu over the course of a year, you'd blame 36,000 deaths on the flu.

Article continues on Page 2.

Title: Re: An idea for an iphone app to combat the swine
Post by towr on May 21^st, 2009, 1:28am

on 05/20/09 at 13:39:18, BenVitale wrote:

Why did the world panic over this flu?

Because people like panicking. People have a hard time making the distinction between taking sensible precautions and panicking about the sky falling down.
There WAS reason to take this flu seriously, especially when we didn't know much about it. Even though the a priori chance of a pandemic is not great, it is a distinct possibility. And you do not want to wait until it's happening before reacting to it.
We did not know how virulent this flu would be, or how deadly; we only knew it was different from the flus we knew. Now we do know that it doesn't seem to share many of the characteristics that made earlier pandemics so deadly. But if we had waited to find that out, and it did have those traits, then we'd be royally screwed.
We need to be prepared for such eventualities. Because the cost is enormous. We don't know what a virus like Spanish flu might do in today's world. People like to say that we'd be able to deal with it; but we don't know. With 2% of the human race at risk, it's not something you should carelessly gamble with. This does not mean we should act like the sky's falling down on us; but it does mean we need to take sensible precautions. If a new virus rears it's head, the sensible thing is to contain it until we know what we're dealing with.
All the people that say this 'panic' by the WHO and governments has been a wasted effort fail to understand what's happening. Consider this, how do you prove that you prevented something from happening? There is no way to tell if all these precautions prevented a pandemic, prevented the virus from spreading and mutating into a deadlier variant. Because if that had lain in the future it has now been prevented. This is the paradox of successful prevention.
Nothing much bad happened. But this in itself says absolutely nothing about whether the WHO and governments overreacted or not. You have to look at the data, data that wasn't available at the time they had to decide whether to act or not. In hindsight it is easy to say they needn't have taken such drastic measures; but this is not a fair criterion.

The problem, really, is people, and the media. As I said, they have trouble making the distinction between making sensible precautions and panicking. This got a lot of media attention, and a lot of it wasn't of good quality. The message should neither have been "We're all going to die", nor "There is nothing to worry about"; media tend to extremes, and this is a problem.
The fact is, we didn't know anything about this flu at the start. The spanish flu also started off mild, seemingly no worse than a normal flu; so the fact people didn't drop dead by the truckload from the start shouldn't ease your mind. We haven't had a chance to test our modern medicines, like tamiflu, against a pandemic; so we shouldn't count ourselves safe, because we haven't got the evidence to back this false sense of security up. It takes time to figure out the nature of a virus, and in the event it's a global killer, you don't want to wait with containing it.
And yet, none of these things warrant panic either. They warrant taking precautions, and researching the virus until we can eliminate all those uncertainties. Precisely what was done.

Saying this isn't worse than a regular flu is missing the point entirely.

Title: Re: An idea for an iphone app to combat the swine
Post by BenVitale on May 21^st, 2009, 4:45pm

Thanks Towr for your insights. I always enjoy reading your posts.

I see a problem with the regression used in this context.

The correlation is not causation. Regression is useful statistical technique that indicates possible links, but doesn't indicate causation in anyway. More people may die when there are more flu cases because the same conditions that increase the flu rate increases other important factors.

As for Mexico, there's no "mystery" as to that nation's much higher death rate. People in poorer countries have overall poorer health and poorer health care.

Have you heard of the swine Flu of 1976?

Public-health officials urged President Gerald Ford that every person in the U.S. be vaccinated for the disease. Then they realized that it was not necessary to vaccinate people.

http://en.wikipedia.org/wiki/Swine_influenza

But we are told that this particular swine flu strain is different from that of 1976.

SARS in 2003. SARS infected only 8,400 people, killing 774 worldwide, before the WHO finally concluded that this virus didn't spread easily through the air.

Then there was the avian and human influenza back in 2005.

The problem exists with the Epidemic and Pandemic Alert and Response system WHO uses to warn us about pandemics, focusing attention and then ultimately asking for billions of dollars in funding.
Every time they manage to scare the masses they get lots of $$ in funding.

Consider this:

- 33 million people suffer from HIV in the world with more than 3 million deaths per year.

- There are 300 million to 500 million cases of malaria per year according to the WHO, giving 1.5 million to 2.7 million deaths.

- More than 1/3 of the world is starving, and the WHO reports that at least 15 million children die of hunger each year.

All health agencies tend to be alarmists and to exaggerate the threat of anything. For this reason, numbers coming from outside of the agencies and their officials tend to be more reliable.

Title: Re: An idea for an iphone app to combat the swine
Post by towr on May 22^nd, 2009, 1:39am

on 05/21/09 at 16:45:27, BenVitale wrote:

I see a problem with the regression used in this context.

The correlation is not causation. Regression is useful statistical technique that indicates possible links, but doesn't indicate causation in anyway. More people may die when there are more flu cases because the same conditions that increase the flu rate increases other important factors.

But what's the alternative? Attributing death only to confirmed flu cases woefully underestimates the death toll. Because, as the article you linked to explains, most people die of complication due to the flu, after it has gone, not of the flu itself. The best thing you can do is a multivariate regression, trying to eliminate as many other variables as possible.
The problem is that you can't experiment. You can only use the impure data that exists. It would be unethical for example, to vaccinate half the people against the flu, and not the other half, and then compare the death rates. And doing it with test animals just isn't the same (also because they don't live their lives the way we do, they won't get into car accidents on slippery icy roads).

Quote:

All health agencies tend to be alarmists and to exaggerate the threat of anything.

I don't think this is the case. The worst case scenario isn't an exaggeration, that's like saying the top prize in the lottery is an exaggeration. It's not, it's just not the likeliest scenario; however unlike winning the lottery, "winning" the worst case health crisis isn't a very good thing. They're not being alarmist when they say "the worst case scenario is ... , and we need to do something to prevent it", it's being cautious. That's what they're there for.
We don't need a health agency sitting around picking their nose chanting the mantra "oh, nothing going to happen anyway".
The problem, imo, is the media, that strips a science and health stories from all their qualifiers and turns "the worst that could happen is ... , and until we know more we should start taking precautions" to "WE'RE ALL GOING TO DIE!!!! (continued on page 2)". Media have a chronic problem of failing at levelheaded, objective reporting on science and health stories. Examples abound on http://www.badscience.net/
As far as I've actually heard the health organizations and people, rather than the media's reporting, it has never been alarmist. They didn't tell us we were all going to die, they told us what preparations and precautions are in place, and why. I found it quite reassuring after the panic the media was stirring up.

Quote:

For this reason, numbers coming from outside of the agencies and their officials tend to be more reliable.

That depends very much on where they come from. Some evidence that they are more reliable wouldn't be entirely out of place either, actually.
The data from health agencies is a much subject to peer review as other data in science. Of course, you also have to bare in mind that you can compile much better data five years after the fact than during. Hindsight is 20-20.
I'm not sure outside groups even have the data when a potential crisis arises, because it's all haphazardly accumulated through hospitals. You'll see the worst cases first, so the lethality -- based on the available data -- will necessarily seem high at first also. If you get 10 cases in hospital, and 5 die, it will seem like 50% mortality. Because you don't know about the 200 people that didn't need to go to hospital; you need time to track down all the cases. And this isn't something you can correct for as the numbers come in, because you don't know the proportion of cases you do know about and the cases you don't know about.

Do you know if there is a report somewhere on the WHO's response to SARS? Since that has been a while ago, perhaps there is an objective evaluation of how appropriately they acted on the data they had at the time.

Title: Re: An idea for an iphone app to combat the swine
Post by BenVitale on May 25^th, 2009, 2:33pm

Towr,

I need more time to think about this. Or, I could answer little bit at a time.

I could start by saying that humans are hard-wired to worry. We evolved as thinking creatures given to assessing and reacting to not only immediate but also long-term risks. We have allowed much nonsense to trigger our natural tendencies towards risk aversion.

We tend to ignore things such as: road accidents, obesity, heart disease, etc.

Why? Because they are constant. We have become accustomed to road accidents, obesity, heart disease, ...

But if something new comes along , like SARS or swine flu or something exotic we pay attention and become fearful.

Title: Re: An idea for an iphone app to combat the swine
Post by towr on May 26^th, 2009, 11:44am

Don't you find it a bit contradictory, to first say we're hardwired to worry, and then state that we don't worry about the things we're most at risk from, such as road accidents, obesity, heart disease, etc?

I'll grant you that we're bad at estimating risk in a lot of cases. Big, rare events have a disproportional impact on us, and consequently we overestimate their likelihood (because people seem to use the heuristic that easier to remember events are more likely). And on the other hand, when we estimate the risk of, say, road accidents, we can look at our usually very good record in avoiding them. Most of us have a lot of experience with not getting into serious accidents; so it shouldn't be surprising to give accidents a low risk-estimate. Similarly, I would expect that people who fly tend to be a lot less worried about plane crashes than people that only hear about planes when there's a crash on the news. There's a huge bias in the data we get through the news, it's invariably bad news. We don't hear about all the planes that land safely, we hear about the crashes.
And there's also something else that might play a role. For most of our (pre)history any news we heard was invariably local. It might not be a stretch to suppose our mind still works under that assumption, and "thinks" that all the catastrophes around the world which the news confronts us with are still local; which would mean we live in a very dangerous location.

On a more psychological level, a factor that may make a difference is the varying level of control on, and understanding of, a situation you have. As a driver, you're in control of your car, and you're quite familiar with the situation. People like being in control (or thinking they are); so they'll generally feel safer. But things like diseases and plane crashes or terrorists are things you have no control about, and there is an intrinsic level of uncertainty. You don't know when it will happen, where, and even if you did, there's little you can do about it; it's a recipe for helplessness and consequent anxiety.

But overall, I don't think people are hardwired to worry; people are hardwired to get on with their lives. Excessive worrying just gets in the way.

Title: Re: An idea for an iphone app to combat the swine
Post by BenVitale on May 26^th, 2009, 12:18pm

The following article suggests that human beings are hard-wired to worry -- depending on how you do it, worry can help you succeed or make you sick

What if you learned to worry well, would it change your life?

Worry is like an emotional crystal ball that allows you to peer into the future and predict potentially negative outcomes.

http://www.cognitivetherapynyc.com/inthenewsDetail.asp?id=210

I'm suggesting that we are predictably irrational.

Have you read "Predictably irrational" by Dan Ariely?

http://www.predictablyirrational.com/

Title: Re: An idea for an iphone app to combat the swine
Post by towr on May 26^th, 2009, 1:07pm

on 05/26/09 at 12:18:21, BenVitale wrote:

The following article suggests that human beings are hard-wired to worry

It just states it, without any evidence or elaboration on what they even mean by it. And it is somewhat contradicting itself by proceeding to describe ways to control/change your worrying; which suggest it isn't hard-wired after all.

The phrase "hard-wired to worry" suggests people worry a lot more than they actually, demonstrably, do. And if people did worry that much they wouldn't be able to live their lives. I mean, just consider the simple act of procreation. The tons of things there to worry about, diseases, pregnancy (with all possible consequences), emotional scarring. Yet most people's brains just shut off and they jump into it. The brain 'knows' the gene's priorities.
Worrying is something to do when you don't have more important things going on.

Quote:

I'm suggesting that we are predictably irrational.

Have you read "Predictably irrational" by Dan Ariely?

No, I haven't. But I'll buy that people are predictable and irrational. However that doesn't mean they're hard-wired in non-adaptive ways; quite the contrary. All our irrationality is either adaptive or a side-effect of an adaptation; or at least it was in our evolutionary environment.

Title: Re: An idea for an iphone app to combat the swine
Post by towr on May 27^th, 2009, 6:48am

"People By Nature Are Universally Optimistic, Study Shows" (http://www.sciencedaily.com/releases/2009/05/090524122539.htm)

Title: Re: An idea for an iphone app to combat the swine
Post by BenVitale on May 28^th, 2009, 1:29am

on 05/27/09 at 06:48:43, towr wrote:

"People By Nature Are Universally Optimistic, Study Shows" (http://www.sciencedaily.com/releases/2009/05/090524122539.htm)

Good article!

Worry is not necessarily a bad thing.

I tend to believe that worry has an evolutionary advantage:
Perhaps there's an evolutionary reason for our ability to worry that enables us to prepare ourselves to cope with threatening situations by stimulating them in our imagination and rehearsing ways of avoiding and overcoming them.