How deadly is bird flu?

The Centers for Disease Control and Prevention, and the World Health Organization, say that H5N1 bird flu kills some 60% of the human beings it manages to infect. Basically, it hasn't infected many people—because it can't be spread from person to person—but most of the people it does infect die.

But this might not be the full story.

After I posted a summary of the current controversies surrounding H5N1 research, I got an interesting email from Vincent Racaniello, a professor of microbiology at Columbia University Medical Center. Racaniello points out that the 60% death rate statistics are based on people who show up at hospitals with serious symptoms of infection. So far, there've only been about 600 cases. And, yes, about 60% of them have died.

However, they don't necessarily represent everybody who has contracted H5N1.

A death rate is only as good as statistics on the rate of infection. If you've got an inaccurate count of the number of people infected, your death rate is going to be wrong. And there's some evidence that might be the case with H5N1.

In a recent study of rural Thai villagers, sera from 800 individuals were collected and analyzed for antibodies against several avian influenza viruses, including H5N1, by hemagglutination-inhibition and neutralization assays. The results indicate that 73 participants (9.1%) had antibody titers against one of two different H5N1 strains. The authors conclude that ‘people in rural central Thailand may have experienced subclinical avian influenza virus infections’. A subclinical infection is one without apparent signs of illness.

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Local snow does not disprove global climate change

Even with all those Snowpocalypseses(?), NASA says that 2011 was still the ninth warmest year on record since 1880—and all but one of the top 10 warmest years have happened in the last 11 years. 1998 is third-hottest, although it's worth noting that the top six years are all close enough that they may as well be fundamentally tied for first. Read the rest
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Ryan Gosling's soulful eyes + smooth statistics

Biostatistics Ryan Gosling will look deeply into your eyes and ask about your p-value.

Via Jacquelyn Gill

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Great Moments in Pedantry: The odds of your existence

What are the odds that you, as an individual, exist? Pretty good, you'd guess, since you're sitting right here reading this. But, in an abstract sense, the chances that you exist are really rather slim. In fact, once you see the full infographic, put together by futurist and designer Sofya Yampolsky of, I'm sure you'll be much more skeptical of your existence.

The infographic is based on this post by Dr. Ali Binazir.

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Odds are good you won't be hit by a satellite this weekend

A retired climate research satellite will plummet to Earth on Friday. There is a 1-in-3,200 chance of it hitting a person. BUT! Don't worry too much about that, says Scientific American reporter John Matson. A 1-in-3200 chance of a piece of the satellite hitting somebody, is not the same as a 1-in-3200 chance of it hitting you, specifically. He calculates the risk of that as 1-in-22 trillion. Read the rest

Deceptive "independent research" from Hollywood front suggests Australians are easily frightened

A press release from a mysterious "independent" Australian research outfit announced that if Aussie ISPs would help the movie industry by threatening the families that Hollywood says are downloading without permission, copyright infringement would fall by a whopping 72 percent.

This is a big number. A very big number. Especially since the same poll question, when asked in France (where the motion picture lobby has succeeded in passing a "disconnect anyone we don't like from the Internet" law) showed that only four percent of downloaders changed their habits out of fear of detection.

No, it's not that Australians are easily frightened. Rather, the Intellectual Property Awareness Foundation (an "independent" firm that lists the MPAA on its board and has no visible clients apart from the entertainment industry) included responses from people who don't download in its poll -- that is, they lumped in the very small number of people (zero, possibly) who said, "I download, and this would make me stop" with the very large number of people who said, "I don't download, but, well, hypothetically, if I did, this might make me stop."

If 72 percent say they would stop sharing after a warning, then 28 percent didn’t agree with this statement. And since only 22 percent of the people said they used file-sharing software in 2011 (the only people who would be affected by a three strikes system), this means that warnings from ISPs wouldn’t even deter people who aren’t the target of this system in the first place.
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Clinical significance is not the same as statistical significance

A great example of why details and context always, always matter, from the surgeon/blogger at The Skeptical Scalpel:

Twelve patients who served as their own controls wore compression stockings for a week and then no stockings for a week alternating. The stockings lowered the amount of fluid in the neck by 60%, a statistically significant difference. So far, so good.

This resulted in another highly statistically significant finding, which was a 36% reduction in episodes of apnea [cessation of breathing] and hypopnea [inadequate breathing]. Sounds good, right? The problem is that the average number of episodes of apnea/hypopnea decreased from 48 per hour to 31 per hour. Patients experiencing more than 30 episodes of apnea/hypopnea per hour are classified as having severe obstructive sleep apnea. This means that the treatment only put the patients in the low range of severe obstructive sleep apnea. They still would require maximum therapy.

Via Ivan Oransky

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Mobile "bandwidth hogs" are just ahead of the curve

A Cisco white-paper on mobile data usage shows that "high bandwidth" users are just early adopters -- the first people to start using high-bandwidth apps like video. In other words, it's not P2P or tethering that mobile operators have to worry about, it's using mobile data in exactly the way it's advertised. (via cmdln) Read the rest