Search results for Q: A: (100)

Q: Did you see 90% of Covid deaths are due to obesity?

A: No

Q: It’s on Newshub: “90 percent or 2.2 million of the 2.5 million deaths from the pandemic disease so far were in countries with high levels of obesity.”

A: So, if that’s true, what countries are we talking about?

Q: With high levels of obesity? Australia, New Zealand, some of the Pacific Island nations, USA, UK,…

A: And what don’t those countries have in common?

Q: Lots of Covid deaths, I suppose.  But Australia and NZ and the Pacific Island countries didn’t have many deaths just because they didn’t have many cases. They don’t tell you anything about the risk

A: Neither does the ‘report’, which says, according to Newshub, “the majority of global COVID-19 deaths have been in countries where many people are obese, with coronavirus fatality rates 10 times higher in nations where at least 50 percent of adults are overweight”

Q: That sounds bad, though? Ten times higher is a lot!

A: How much do you think being overweight increases the risk of death?

Q: Well, if 50% overweight means ten times the risk, maybe a factor of twenty?

A: Yeah nah. Less than double, according to that very same report. (PDF, p13)

Q: So where do they get such a strong association?

A: Well, what are the main risk factors for dying of Covid?

Q: Um. Age?

A: And?

Q: Heart disease? Diabetes?

A:

Q:

A:

Q: Having Covid?

A: Exactly.  So we’d need to look at the proportion of infected people dying (the case fatality rate), not the total number of deaths, and we’d ideally want to compare countries with similar age profiles. Instead, Newshub shows us a graph of deaths, basically like this

Q: Why are some of the dots black?

A: They are countries that were missing from the Johns Hopkins Covid data, and so were missing from the original graph, mostly small nations like Samoa and Tonga and Timor-Leste with very few cases

Q: And what’s the dot on the left that isn’t in the graph on Newshub?

A: Afghanistan. I don’t know why it’s not there.

Q: So what about for risk of dying if you get Covid?

A: Here’s what it looks like for case fatality rate

Q: That’s…surprisingly unimpressive. Well, except for that one country…

A: Yemen

Q: Things they don’t need right now, number #1

A:  Too true.

Q: So the massive correlation?

A: Well, overweight is common in the USA, the UK, Brazil, and various other large countries that have handled the pandemic badly. While I suppose you could argue that handling the pandemic well should go with handling other public health issues well, the empirical evidence would not really be in your favour on that one.  You could also listen to a slightly different approach to the data from David Spiegelhalter and Tim Harford on BBC’s “More or Less”

Q: Is four a lot?

A: Depends on the context. Lockdowns, yes. Incursions per 46000 people through MIQ, no.

Q: We’ve had four lockdowns in Auckland, right?

A: Yes

Q: And how many cases let through MIQ for each 46000 people?

A: About four

Q:

A:

Q: ಠ_ಠ

A: My point, and I do have one, is that more people need to say what their criteria are. If you think four lockdowns is unacceptable, what’s your target that you can argue a realistic system would achieve? If you think 10 cases in 115000 MIQ visitors is a good result, what would it take to be a bad result?

Q: So what’s your threshold?

A: I don’t know. That’s why I haven’t been making comments about the overall performance being good or bad.

Q: Did you hear that pizza boxes are going to stop the Covid vaccine working?

A: You mean people will mistakenly store the vaccine in pizza boxes instead of ultracold deep freeze?

Q: No, research shows that pizza boxes and lots of other things contain chemicals that stop vaccines working. According to the Guardian.

A: Even the Guardian says “At this stage we don’t know if it will impact a corona vaccination”

Q: And is that true?

A: No.

Q: What?

A: The story says these chemicals are ubiquitous, with the majority of people being exposed.

Q: Yes, that’s the scary part

A: So people in the Covid vaccine trials will also have been exposed.

Q: I suppose so?

A: The trials estimate the effect of the vaccines in a reasonably diverse group of people from the US population.  If polybathroomfloorine, or anything else widespread, has an adverse effect on the vaccines, that’s already baked in to the trial results.

Q: So without the chemicals, the vaccines might have been, say, 95% effective?

A: If you believe there’s a relationship, yes, that’s what you’d think.

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.

Q: Did you see hydroxychloroquine is back?

A: No

Q: In the Herald (blamed on news.com.au) ‘Hydroxychloroquine: Divisive drug may hold secrets to stopping Covid-19‘ and ‘Covid 19 coronavirus: Hydroxychloroquine: The drug that could be our saviour‘. What’s the news?

A: There’s a new Australian trial in healthcare workers, to see if taking the drug before you get exposed will protect you  from infection — previously there had only been evidence that it doesn’t help  if you take it when you’re already sick.

Q:  And what were the results?

A: There aren’t any results. There won’t be any results for quite a while.

Q: When?

A: The entry at the Clinical Trials Registry says they plan to finish taking measurements at the end of the year, and the story says the results will be in by January.  Though  the Trials  Registry also  says they plan to recruit 2250 people and follow them for four months, and the story says they have ‘roughly 200’ people now. So it’s not completely clear.

Q: Will it work?

A: We don’t know. That’s the point of the trial.   We know it’s nowhere near 100%  effective,  because people taking hydroxychloroquine for auto-immune diseases have  ended up with COVID, but it’s possible that it provides some useful level of protection. It’s also very possible that it doesn’t.

Q: And healthcare workers are at high risk, so it would be most useful for them?

A: Yes, and healthcare workers are already trying to do all the other protective things, and they are still at high risk, so the drug might be a useful addition even if it’s only moderately effective

Q: And for the rest of us?

A: It’s unlikely to be as safe or effective as masks.

Q: If it does work, it will be pity that the politicisation has slowed it down

A: Well and the fact that it doesn’t work after you get sick. But yes, that’s one of the points the story makes, quoting both the lead researcher and a study participant

Q: This is the story that’s illustrated with a picture of Donald Trump?

A:  <sigh>

Q: Apart from the headline and picture, the story is ok?

A: Well, later on, one of the researchers says

“For example if there was a case in a meatworks or an aged care, you’d go there and give the drug to all the residents or workers to try to prevent them getting Covid-19,” he said.

Q: But how is that before they’re exposed? If there’s a diagnosed case, they’ve already exposed people and they will be isolated in the future and not expose anyone else. It’s the people who are already exposed that are the problem.

A: I hope he’s just saying there’s a potential for using it as post-exposure prophylaxis in the future, after a different trial

Q: That … could have been clearer.

A:  And the biggest problems for healthcare workers in the current Australian outbreak seem to have been a shortage of protective equipment or poor ventilation, so you’d hope irresponsible news headlines about a miracle cure wouldn’t distract from that.

Q: Did you see this study saying vaping makes you five times more likely to get COVID?

A: Yes, but it’s not in the news, so it doesn’t count for StatsChat

Q: Newshub covered it.

A: Ok. Not entirely convinced

Q: They did a survey and they did lots of reweighting, the way you like. And said exactly what questions they asked.

A: Yes…

Q: So it’s not dodgy like the paper about heartburn drugs

A:  No, not like that.

Q: What’s your problem, then

A: The first problem is the proportion of people with COVID tests. No, actually the first problem is that COVID is so rare that this isn’t a reliable way to estimate proportions, and the second problem is that getting a test depended on a lot of other factors back then.  The third problem is the proportion of people with COVID tests

Q: Which is?

A:  Over 5% of people 13-17 and over 10% of people 21-24. By May 14, when the total cumulative number of tests in the whole US was only about 5% of the population — and you’d expect lower testing rates in younger people.

Q: Where are those numbers in the paper?

A: It’s a combination of the user and non-user columns in Table 1, using the proportions in the Supplementary Material. Which, again, the authors should get credit for providing.  What they call “COVID-related symptoms” are also very high: 14% of non-vapers and 26% of vapers reported having the symptoms right at the time they were surveyed.

Q: You’d think we would know if vaping increased these symptoms that much, separately from COVID. But if they oversampled people at high risk of COVID, it should at least be comparable across their survey

A: They did separate surveys for users and non-users of e-cigarettes, so that’s not actually obvious.

Q: But weighting?

A: Yes, but that doesn’t help as much with matching the surveys to each other, especially as they don’t have separate census totals for vapers and non-vapers.  In particular, in mid-May COVID was concentrated in relatively small areas of the US, and it would have been more valuable to make sure the locations matched up.

Q: But we know that smokers are at higher risk of catching the coronavirus, so this just confirms that.

A: Surprisingly, no.  Smokers don’t seem to be at higher risk of getting infection — and I guarantee that it’s not because no-one tried to show they were.  They may be at higher risk of getting seriously sick if they are infected, but even that’s not as clear as you’d expect.

Q: So should we believe this?

A: It’s not as simple as that.  This study does provide some evidence, but not as strong evidence as the researchers think. It certainly isn’t strong enough evidence to change policy on the regulation of e-cigarettes; whatever  you believed about that before seeing this study, you should believe about the same afterwards. And you probably do — it’s not a topic where people are noted for changing their minds.

Q: Did you see that COVID actually came from Italy?

A: No.

Q: Radio NZ “samples taken in Milan and Turin on 18 December showed the presence of the SARS-Cov-2 virus…..may have been circulating before China reported the new disease to the WHO on 31 December.”

A: Well, yes, but the date China told the WHO isn’t very biologically meaningful.  The first hospital admission in Wuhan was 16 December.

Q: That’s still pretty early to see it in Italy, though.  What does the paper say about how it got there and how it took more than another month to emerge?

A: The press release says “did not automatically imply that the main transmission chains that led to the development of the epidemic in our country originated from these very first cases”. There isn’t a paper.

Q: The preprint, then?

A: There is only the press release.

Q: That’s pretty fucking unsatisfactory, isn’t it?

A: Yes

Q: At least the dexamethasone crew had some excuse for thinking their results were needed urgently

A: Yes.

Q: Are these just some cranks, then?

A: No, that’s what’s annoying.  They have been doing wastewater testing for some time; they say they confirmed the positive tests with a different assay in a different lab; they talk about having sensible controls; it’s all what you’d like to see, only you’d like to actually see it.

Q: These tests are pretty reliable, aren’t they

A: Well, they haven’t told us what tests they used, but the ones you would expect them to have used should give very few false positives.

Q: So it would be surprising if the results were wrong?

A: Yes, but it would also be surprising if the results were right, so unquantified surprise doesn’t get us very far.

Q: Two separate cities, though? How many people would you need in each city for a positive test?

A: That’s one of the other things they don’t say.  An Australian study with two positive results estimated hundreds of cases, but maybe the new Italian results used more sensitive tests. And it’s possible for a person to contribute to the wastewater flow in both Milan and Turin on the same day. I have done so.

Q: Can they do the genome thing on these samples to see how they relate to the early outbreak in Wuhan and the much later Italian outbreak?

A: They don’t…

Q: …say.  Right.

A: The Australian study did do some sequencing, though not of the whole genome, only of one gene.

Q: How could the virus have stayed undetected until the outbreak in February? Was it in the sewage all that time?

A: They say they found it in Bologna in a sample from January 29, and I think the press release is saying there were positive samples in Milan and Turin in January.

Q: So not just a tourist group.  You’d expect more people to have been sick during January, wouldn’t you?

A: Yes. That’s why it’s reasonable that the tests might have be wrong, which would not ordinarily be a good explanation.

Q: Did you see that going to the opera makes you live longer?

A: No, it just makes it feel longer

Q: ◔_◔

Q: This story, from the New York Times.

Now, there is evidence that simply being exposed to the arts may help people live longer.

Researchers in London who followed thousands of people 50 and older over a 14-year period discovered that those who went to a museum or attended a concert just once or twice a year were 14 percent less likely to die during that period than those who didn’t.

A: Actually, if you look at the research paper, they were just over half as likely to die during the study period: 47.5% vs 26.6%. And those who went at least monthly were only 60% less likely to die: 18.6% died.

Q: You don’t usually see the media understating research findings, do you?

A: No. And they’re not.  The 14% lower (and 31% lower for monthly or more frequent) are after attempting to adjust away the effects of other factors related to both longevity and arts/museums/etc

Q: You mean like the opera is expensive and so rich people are more likely to go?

A: Yes, although some museums are free, and so are some Shakespeare, etc,

Q: And if you can’t see or hear very well you’re less likely to go to opera or art galleries. Or if you can’t easily walk short distances or climb stairs?

A: Yes, that sort of thing.

Q: So the researchers didn’t just ignore all of that, like some people on Twitter were saying?

A: No. The BMJ has some standards.

Q: And so the 14% reduction left over after that is probably real?

A: No, it’s still probably exaggerated.  Adjusting for this sort of thing is hard.  For example, for wealth they used which fifth of the population you were in. The top fifth had half the death rate of the bottom fifth, and were five times as likely to Art more often than monthly.  For education, the top category was “has a degree”, and they were half as likely to die in the study period and 4.5 times more likely to Art frequently than people with no qualifications.

Q: “Has a degree” is a pretty wide category if you’re lumping them all together.

A: Exactly.  If you could divide these really strong predictors up more finely (and measure them better), you’d expect to be able to remove more bias.  You’d also worry about things they didn’t measure — maybe parts of the UK with more museums also have better medical care, for example.

Q: But it could be true?

A: Sure. I don’t think 14% mortality rate reduction from going a few times a year is remotely plausible, but some benefit seems quite reasonable.

Q: It might make you less lonely or less depressed, for example

A: Those are two of the variables they tried to adjust for, so if their adjustment was successful that’s not how it works.

Q: Isn’t that unfair? I mean, if it really works by making you less lonely, that still counts!

A: Yes, that’s one of the problems with statistical adjustment — it can be hard to decide whether something’s a confounding factor or part of the effect you’re looking for.

Q: But if people wanted to take their kids to the museum over the holidays, at least the evidence is positive?

A: Well, the average age of the people in this study was 65 at the start of the study, so perhaps grandkids.  Anyway, I think the StatsChat chocolate rule applies: if you’re going to a concert or visiting a museum primarily for the health effects, you’re doing it wrong.

Q: Did you see that a harrowing study of 46,000 women shows hair dyes are heavily associated with cancer?

A: Harrowing?

Q: According to FastCompany.

A: That’s just the headline, though.

Q: “You know how you don’t see very old people with dyed hair? There may be a reason for that: Hair dye is heavily associated with cancer.”

A: That would be a heavy association.

Q: So is it true? There’s a link, even.

A: “We observed a 9% higher breast cancer risk for permanent dye use in all women but little to no associated risk for semipermanent or temporary dye use.”

Q: That’s… not as harrowing as I expected. Would that kill off a big fraction of hair-dye users?

A: Well, not very many men. For women the lifetime risk, which is the cumulative risk by the time you’re ‘very old’, is about 1 in 8. Increasing that by 9% would be about one extra breast cancer case per hundred hair-dye users.

Q:  So that’s not why very old people don’t use hair dye

A: There are probably other factors in play, yes.

Q: It’s just breast cancer, though. What about the effect on other cancers?

A: They didn’t look.  They mostly expected a risk on breast cancer, because of theories about ‘estrogen disruption’.

Q:  The story says the effects are bigger in Black women.

A: It looks like they probably are, though there’s a lot of uncertainty because Black women were only 10% of the study.

Q: Nothing about hair dye in men?

A: It was a study of sisters of people with breast cancer, so no men.

Q: Also too, no generalisability?

A: It’s not quite that bad, but, yes, it’s not clear how well this generalises. It could be that these women are more susceptible to hair dyes. Or not.

Q: What did previous research find?

A: It’s mixed. A big study in Black women in the 1990s didn’t find an association, but another current study did.

Q: So do we believe it?

A: We aren’t Black women who use hair dye. On several counts.

Q:

A: It certainly could be true, but the evidence isn’t overwhelming.

Q: Did you see that asthma inhalers cause as much greenhouse gas emission as eating meat?

A: Yes

Q: That’s huge!! It’s like 15% of global warming!

A: No

Q: Yes!

A: No. The BBC claim is that the CO₂ equivalent of one person‘s use of asthma inhalers is comparable to one person‘s meat consumption. A lot more people eat meat than use asthma inhalers.

Q: Oh. That’s still quite a lot, though?

A: They say it’s about 4% of emissions from the UK healthcare system. About 0.15% of the UK total.

Q: And compared to meat?

A: Well, the BBC don’t link, but if you find the research paper (PDF) and follow its link for the meat claim, you get a graph saying about 0.9 tonnes CO₂ equivalent per year for an average person switching to a plant-based diet in the UK, compared to the 165kg average they’re claiming for the inhalers (range of 150-400kg).

Q: Isn’t 165kg less than 0.9 tonnes?

A: Yes, quite a bit less.

Q: So why do they get away with that in a published research paper?

A: It’s not the point of the paper. The point is to look at the financial cost of the National Health System switching to asthma inhalers that don’t use greenhouse gases, for the subset of people who can use them.  The costs aren’t that bad. They also suggest other sensible ways to reduce emissions, such as recycling or incinerating used inhalers, and labelling them with the number of doses so that they don’t get discarded early.

Q: What are we doing about this in New Zealand?

A: A bit more than for meat.  There’s an actual plan to reduce total imports of these synthetic greenhouse gases starting now and going through 2036, but in the short term that’s mostly going to affect air conditioners, not inhalers. Pharmac asked for bids for asthma inhaler supply through 2023, and (earlier this month) proposed settling on two products with HFC-134a propellant, which is the less-bad of the two greenhouse gases currently used in inhalers. 

Q: If the point is financial costs, isn’t the comparison with meat just trolling?

A: Pretty much.  Eating plants is an individual choice, it’s not an all-or-nothing change, it doesn’t take a doctor’s prescription, and you don’t need to have asthma to do it.  You could just decide to eat less meat, or give up beef, or your whole household could eat less  meat. And eating less meat doesn’t have negative health implications.

Q: So people should just use their inhalers like their doctor says?

A: Absolutely.  Modern preventer inhalers are a major achievement of medical and chemical science.  For any individual, there should be many possible lifestyle changes higher up your priority list than worrying about your model of asthma inhaler.  Maybe get ready to lobby Pharmac to take emissions into account when they next put out a bid for inhalers,  in 2022 or thereabouts.