Posts filed under General (3148)

Elections are designed  to  produce a  result: someone wins. The losing side doesn’t get to enact a fair share of their program just for getting close.

Clinical trials aren’t like that.  They do feed into regulatory decisions, which may be  yes/no in a similar way, but when we talk about what was learned in a trial it isn’t just binary, or shouldn’t be.  Unfortunately, there’s a tendency for “the trial did not provide convincing evidence of mortality  reductions” to get simplified to “the trial did not provide any evidence of  mortality reductions”  and then to  “the treatment  does not reduce mortality”.

The NIH trial of remdesivir for Covid was a typical example. Here’s the result.

The estimated reduction is about 25% — not a cure, but quite worthwhile if true.  There’s a lot of uncertainty: the trial data are consistent with there being no benefit (a ratio of 1; the vertical line) and equally consistent with a 50% mortality reduction.  The results still got described as “remdesivir does not reduce mortality”.

This matters, because we need to distinguish an inconclusive but moderately favourable result from the other sort of negative trial. This week we got results from the larger  SOLIDARITY trial, coordinated by  the WHO.  Here’s a comparison of the two

The two trials are clearly consistent with each other, but the uncertainty around the results is a lot smaller with the WHO  trial.  Importantly,  the estimated  benefit in the WHO trial is a much less impressive 5% reduction, and the lower limit is about 20%.  The WHO trial can reasonably be summarised as  saying ‘there is no substantial reduction in mortality with remdesivir’, and it wouldn’t be too much of a stretch to say ‘remdesivir doesn’t reduce mortality’  (in patients similar to these ones).

We can combine the two sets of information:

The  diamond is the uncertainty interval for the combination of the two trials (it’s a different shape so you  don’t think it’s a third trial).  It mostly follows the larger WHO trial, where most of the information is, but it’s shifted a little to the left because of the more positive information from the NIH trial.  The takeaway point is the same as from just the WHO trial, though: remdesivir doesn’t reduce mortality much, if at all.

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 132 matches played, 88 of which were correctly predicted, a success rate of 66.7%.
Here are the predictions for last week’s games.

Predictions for the Final

Here are the predictions 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 3

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 12 matches played, 10 of which were correctly predicted, a success rate of 83.3%.
Here are the predictions for last week’s games.

Predictions for Round 3

Here are the predictions for Round 3. 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 Preliminary Finals

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 166 matches played, 114 of which were correctly predicted, a success rate of 68.7%.
Here are the predictions for last week’s games.

Predictions for the Preliminary Finals

Here are the predictions for the Preliminary 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.

Team Ratings for Round 6

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 35 matches played, 23 of which were correctly predicted, a success rate of 65.7%.
Here are the predictions for last week’s games.

Predictions for Round 6

Here are the predictions for Round 6. 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 Semi-finals

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 130 matches played, 86 of which were correctly predicted, a success rate of 66.2%.
Here are the predictions for last week’s games.

Predictions for the Semi-finals

Here are the predictions for the Semi-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.

Q: Newshub says they know the demographic that’s worst at social distancing

A: Presidents? Elderly real-estate developers? Americans?

Q: The headline doesn’t say

A: Well, of course not. Then you might not click. It’s men, and young people

Q: So, the majority of the population is the worst?

A:  Have you been in a supermarket lately?

Q: Fair point. How did they tell who was good and bad at social distancing? Did they use hidden cameras and AI video processing?

A: They asked them

Q: So men and younger people just say they are the worst.

A: Yes, basically.

Q: And this was in Canada and the United States?

A: No, the researchers were in Canada and the United States. The participants were from around the world.

Q: How around?

Q: Well, about 700 from Canada, nearly 200 from UK, 72 from Serbia, 61 from USA, 39 from Malta, 4 from Luxembourg,  1 from Brazil, and … you’re looking impatient

A: How about New Zealand?

Q: None

A: How did they do the sampling?

Q: The research paper says “This cross-sectional study was conducted online with a convenience sample of English-speaking adults”

A: Like — Twitter polls or something?

Q: “The survey was hosted on the Qualtrics platform and was distributed via snowball convenience sampling through co-author’s professional and personal networks and social media accounts (e.g., Twitter, Facebook); ads posted on University of Calgary online platforms; via paid ads (35.00 CAD/day) posted on Facebook targeting English-speaking adults residing in North America and Europe.”

Q: “Snowball convenience sampling”?

A: Translates as “Please retweet for reach”

A: That… sounds like the sort of thing you usually call a bogus poll.

Q: It does, doesn’t it.

A: But it seems to be getting the right answer

Q: If you can tell that, you didn’t need the survey.

Team Ratings for Round 2

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 6 matches played, 5 of which were correctly predicted, a success rate of 83.3%.
Here are the predictions for last week’s games.

Predictions for Round 2

Here are the predictions for Round 2. 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 1

Yes, the games have already been played but these are my predictions posted here for completeness.

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.

Predictions for Round 1

Here are the predictions for Round 1. 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 22

OK, so this is late, with only one game to play. It has been a crazy time trying to keep up with changes to fixtures. The Gloucester versus Northampton game was forfeited by Northampton and the result given to Gloucester 20-0. I think I will follow FlashScore on that game and ignore the allocated result.

I have also missed the start of the Pro14. I haven’t even sorted out the fixtures for that yet, or chosen parameters, but will catch up tomorrow I hope.

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 126 matches played, 83 of which were correctly predicted, a success rate of 65.9%.
Here are the predictions for last week’s games.

Predictions for Round 22

Here are the predictions for Round 22. 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.