There’s a headline in the Herald: Heart disease linked to non-stick cookware: study. There seems to have been some loss in translation for both the article and the headline.

The journal press release says

Exposure to perfluorooctanoic acid (PFOA), a manmade chemical used in the manufacture of some common household products, appears to be associated with cardiovascular disease and peripheral arterial disease in a study of 1,216 individuals

That is, PFOA is used to make non-stick cookware, but cooking with non-stick cookware isn’t an especially important source of it, and the article doesn’t say it is.

Unlike the Teflon in non-stick coatings, which is as inert as a very inert thing, PFOA is quite chemically interesting. There are traces of PFOA in all sorts of things, and it accumulated in the environment, which is why it’s interesting to public health researchers.  If you want to read more, Wikipedia is a bit alarmist about the health evidence but reasonably informative.

The story goes on to say

From a statistical point of view it’s strange  that the researchers just used four years of NHANES data, from two non-adjacent two-year periods.   The study keeps going year after year, and they are now measuring PFOA and related compounds on greater numbers of people.  As a service to the StatsChat readership, I just spent 15 minutes downloading and analysing the 2007-2008 data, which has PFOA measurements on 2100 people, 80 of whom reported coronary heart disease.  I didn’t do as thorough a job of ruling out other risk factors (such as cholesterol or high blood pressure), but it’s still interesting to note that there is absolutely no sign of an association between coronary heart disease and PFOA levels in the 2007-2008 data.

From today’s Herald …

Choose carefully, $23m is at stake

Today’s $23 million Big Wednesday draw is the fourth-largest prize in Lotto history.

And while there is no secret way to guarantee hitting the jackpot, a mathematician says you can boost chances of not having to share any cash you do win.

Associate Professor of Statistics at the University of Auckland David Scott said: “There’s no way of increasing your chances of winning but it’s possible to increase your chances of getting more money and not having to share it.

“Avoid the numbers of 1 up to 30, where people choose their birthdays.”

Read the rest of the story here.

All decision rules based on observed data make mistakes, whether they are detecting the Higgs Boson or breast cancer.  And the more resources you can invest in each decision, the lower you can (typically) push the error rate.

Copyright enforcement has been a dramatic example of the opposite trend.  A century ago, individuals basically couldn’t infringe copyright in any meaningful way, so the occasional disputes got settled by expensive lawsuits.  In the modern world, copying is easy, so the companies that own lots of copyrights are looking for cheap and dirty ways to detect and stop copying.  Of course, the error rate goes up.

A dramatic example happened last night, when the live video feed for the Hugo Awards ceremony at the World Science Fiction Convention was shut down  by automated filtering systems at the company doing the broadcasting. One of the awards, for “Best Dramatic Presentation, short form” was being given for a Doctor Who script.  Clips from the TV show were shown — with full permission of the copyright owners, not that permission would have been necessary for this purpose — and some computer program made a false positive decision.

[Update: the same thing happened, briefly, to the YouTube feed of the Democratic National Convention later the same week]

The Herald has a story about junk food being linked to dementia.  The story itself is fine, but the sources are interesting:

Too much fatty and sweet food can increase insulin levels causing fat, muscle and liver cells to stop responding to the hormone, Medical Daily explained.

When the brain stops responding to insulin our capacity to think and create new memories is hindered, according to the paper recently published in New Scientist magazine.

 Medical Daily is an aggregator of medical stories — it’s a good place to find interesting research with lively descriptions, but it’s not very selective.    It’s a very popular source for the mass media and for alternative-medicine blogs.   The unusual aspect of the story is the primary source, New Scientist.   New Scientist is not a research journal, it’s a popular science magazine.  It used to be the best source in the world for accessible, detailed, science journalism, and although it’s become a bit sensationalist, there’s still a lot of good material there.   It has never been a primary source, and it hasn’t suddenly started publishing new research.

In fact, the New Scientist article is well worth reading: it describes the theory that some (most?) Alzheimer’s disease is due to insulin resistance in the brain, with quotes from researchers and links to the original research.  The “Type III diabetes” theory of dementia is definitely a minority view, and the evidence for it is thought-provoking, but not definitive.  There doesn’t seem to be any reason why it couldn’t be at least partly true, but the same could have been said for the aluminium theory of dementia in its early days.

The only good thing about the diabetes theory of dementia is that while we’re not great at treating insulin resistance, we’re a lot better at it than we are at treating Alzheimer’s.

Stats Chat has had a few nice mentions in dispatches over the past few days, and in this blog-eat-blog world, we thought we oughta share them.

Thanks to Janet McAllister for describing us, along with a couple of other blogs, as “excellent” and “useful” in her New Zealand Herald  column on the weekend.

And this from Public Address, Russell Brown’s thoroughly readable  blog, about his sneak preview of the new, tabloid Herald: The new pages better accommodate the use of infographics – and, happily, editorial staff will have received three training sessions in the use of statistics by the time the paper relaunches. This ought to be a more productive relationship between the Herald and the University of Auckland’s Statistics faculty than the paper having its homework constantly corrected in StatsChat.

Stats Chat just might have run one of those training sessions, on the Monday before last, and we  just might have called it “Learning to Love Statistics: A workshop for journalists”. Thumbs up to the Herald – its journos have had, or are about to have, a session with Statistics New Zealand about how they can best use its marvellous online tools.

And we aren’t out to hassle the Herald, honestly. It’s just that we’re in Auckland, and the Herald’s published seven days a week, and we are still loyal subscribers to the old-fashioned paper product …

Congratulations to Mark Bellhouse for his nomination of good reporting of a drug use study. Thomas Lumley also posted about the story here.

That’s a five-set Venn diagram, invented in 1975.  Some mathematicians have just worked out how to do an 11-set one.

These are pretty, and a computational and mathematical achievement, but unfortunately they don’t have any of the properties that make Venn diagrams a marginally-useful visualization method.     (via)

Andrew Gelman, of Columbia University, wrote an article a few months ago called “Statistics for Cigarette Sellers”

Remember How to Lie with Statistics? It turns out the  author worked for the cigarette companies… It appears he was also working on a book in the late 1960s called How to Lie with Smoking Statistics, which the publisher saw “high likelihood of proceeding into print.”

His blog has a largely overlapping post, but with a bit more material (and discussion in comments).

This appeared in Uni News,  the internal University of Auckland magazine sent to a wide outside audience, a week or so after the end of the Super 15. David came top equal with sports writer Dylan Cleaver, and says he’ll be spending time over this summer “looking at some possible improvements to the prediction method”. Watch this space!

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday September 7 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of September 1 – 7 2012 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.

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