Posts filed under General (3156)

Quite some time ago, I wrote about a story on vitamin D and diabetes:

A: Someone needs to do a randomized trial, where half the participants get vitamin D and half get a dummy pill. If the effect is real, fewer people getting vitamin D will end up with diabetes.

Q: That sounds like a good idea. Is someone doing a trial?

A: Yes, Professor Peter Ebeling, of the the University of Melbourne.

Q: Is there some useful website where I can find more information about the trial?

A: Indeed.

Q: Will it work?

A: No.

Q: Are you sure?

A: No, that’s why we need the trial.[…]

While the clinical trial registry hasn’t been updated, there are now published results from this trial.  The researchers didn’t get to their planned 160 participants; they gave up at 95 because of slow recruitment.  Even so, if the results had been as dramatic as in the observational studies, they would have been able to see the benefit.

They didn’t:

In this 6-month RCT of vitamin D and calcium supplementation in which over 90% of the participants reached the target serum 25(OH)D concentration of 75 nmol/L, there was no effect of supplementation on any measure of insulin sensitivity, insulin secretion or β-cell function in multi-ethnic vitamin D-deficient individuals at risk of type 2 diabetes (with prediabetes or an AUSDRISK score ≥15).

These results are no fun, so they have not received the same media attention as the observational correlations that prompted the trial, even though they are more reliable and more relevant to individual health choices.

Team Ratings for Round 18

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 122 matches played, 69 of which were correctly predicted, a success rate of 56.6%.

Here are the predictions for last week’s games.

Predictions for Round 18

Here are the predictions for Round 18. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

• Visualizing the Twitter networks of NZ MPs: on the Herald data blog, a post by Chris McDowall, and additional graphics by Jayne Ihaka.  
  Now we just need a way to tell which accounts are actually used by MPs and which ones are twitterwallahs.

• There was a big discrepancy among bookies on the odds for the Greek referendum. Paddy Power estimates an 80% chance of ‘yes’ and has paid out winnings early. Betfair is almost certain of “No”.  The wisdom of crowds has definite limitations, especially in situations where no-one really has a clue.

•  Kate Hannah, on the Te Punaha Matatini blog, writing about women and Royal Society of New Zealand prizes (which in their case they have not got)

• Sense about Science have a new guide to screening tests. I’ll repeat my testing soundbite: “Screening is the opposite of treatment: you go in healthy and come out with a disease”.

• Measuring happiness: a discussion at the New York Times and an independent (I think) skeptical post by John Quiggin arguing for measures of unhappiness.

Team Ratings for Round 17

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 118 matches played, 67 of which were correctly predicted, a success rate of 56.8%.

Here are the predictions for last week’s games.

Predictions for Round 17

Here are the predictions for Round 17. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Team Ratings for the Final

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 124 matches played, 81 of which were correctly predicted, a success rate of 65.3%.

Here are the predictions for last week’s games.

Prediction for the Final

Here is the prediction for the final. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Team Ratings for Round 16

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 110 matches played, 62 of which were correctly predicted, a success rate of 56.4%.

Here are the predictions for last week’s games.

Predictions for Round 16

Here are the predictions for Round 16. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Team Ratings for the Qualifying Finals: Correction

I made a mistake in entering the fixtures and had the Waratahs playing away.

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 122 matches played, 80 of which were correctly predicted, a success rate of 65.6%.

Here are the predictions for last week’s games.

Predictions for the Qualifying Finals

Here are the predictions for the Qualifying Finals. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

• A nice example of analysis using open data: trends and risk factors in mortgage default in the US, by Todd Schneider (via mathbabe.org)

• From Vox, for map nerds: “Countries that are South Sudan” in red, “Countries that are not South Sudan” in green, “No data” in grey
  

• Medical marijuana laws didn’t lead to an increase in teenage marijuana use in the US (MinnPost, Lancet Psychiatry). This is less unsurprising than it sounds, because in some of the states, (eg, California) the medical-use requirement is not all that stringent.

• A Tumblr about the “first book on data visualisation best practice”, published 100 years ago by Willard Brinton (via @alberto_cairo)

• Survey research finds that people who (claim to) have more sex are (or claim to be) happier. As XKCD has pointed out, this is something you can’t easily do a double-blind randomised trial of.  But you could do a trial of encouraging people to have more sex. It didn’t make them happier. This is an issue more generally with lifestyle changes: just because a lifestyle difference would be good, it doesn’t necessarily mean that a doctor telling you to make the change will be good. (via Tim Harford)

• Google Research was looking for ways of visualising what actually happens in different layers of a computational neural network. They used feedback of images and amplification of layers to get things like
  

• Nice story in the Herald about second languages in Auckland. (though also note the Herald search page finds 514 stories with the phrase “melting pot”)

Team Ratings for Round 15

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 103 matches played, 58 of which were correctly predicted, a success rate of 56.3%.

Here are the predictions for last week’s games.

Predictions for Round 15

Here are the predictions for Round 15. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Team Ratings for Round 19

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 120 matches played, 79 of which were correctly predicted, a success rate of 65.8%.

Here are the predictions for last week’s games.

Predictions for Round 19

Here are the predictions for Round 19. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.