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This is bad. I've been graphing the exp curve for Italy, UK and USA and the USA curve is fearsomely steep. Italy has more cases now but the USA is growing faste

This is bad. I've been graphing the exp curve for Italy, UK and USA and the USA curve is fearsomely steep. Italy has more cases now but the USA is growing fastest and looks like it will match Italy's on ~March 28th (looking at the most recent 10 points, see below) The rate of growth in the USA, extrapolated, is just huge. Looking at the whole curve it does not match an exponential well, I think the early part is skewing it. If we take the last 10 data points, they fall very well onto the curves for all 3 countries, and that curve for the USA is horrific. I'm not an epidemiologist nor statistican so it would be irresponsible to put my predicted figures here, but christ, if I'm right the US is going to be reeling in just a few day. Edit: @mnl below has pointed out that infection is not an exponential but on the whole a logistics curve (s-shaped curve https://en.wikipedia.org/wiki/Logistic_function https://en.wikipedia.org/wiki/Logistic_function). He is correct. However in early stages I believe an exponential MAY be a decent approximation (and I'm reading up on it now). However, the inflection in the 'S' (where new infections would start to slow down) would be expected to be at far higher figures than those I'm looking at - a few tens of thousands of reported infections per country currently - and it's not even close to that (populations of multiple millions in each country).

Wowfunhappy 7y ago
But how much of the US’s growth is due to us finally having some (albeit not enough) testing?
- throwaway_pdp09 7y ago
  Good question, I don't know. If it helps, a quick search got this https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/testing-in-us.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Ftesting-in-us.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/test... See table at bottom.
- tyingq 7y ago
  That's a very good point, and the lack of tests had a secondary effect. Nobody here took it very seriously at first, because the numbers were very low.
- simonh 7y ago
  This is key. We really can't compare countries confirmed case numbers directly because they are operating very different testing programmes. Just look at Germany. More confirmed cases than the USA, but a quarter of the deaths. Germany also has 80% as many cases as Spain, but about 5% as many deaths. All that, without a severe lockdown. Clearly something completely different is going on there than in many other countries, and it seems they have an extremely effective and well organised testing system. They're testing about 160,000 people a week. In comparison, the UK to date has only tested around 50,000 people in total so no wonder our case numbers are far lower, even though we have double the number of deaths. So Germany is an outlier, but it just goes to show even for other countries you can't just compare the curves and draw any definitive conclusions without also looking at the testing regime. This is where the experts with their detailed population models and simulation tools come in.
  - hallohallohallo 7y ago
    It is the health care system like number of ICUs, training of doctors and stuff like not being able to get antibiotics simply over the counter like in Italy. If my memory serves me right e.g. in Italy 29% have a resistance to antibiotics, in Germany only 0.4%.
    - simonh 7y ago
      People don't become resistant to antibiotics, bacteria do and resistant bacteria in Italy would just spread to Germany. Anyway Covid-19 is a virus, not a bacterium.
      - guiriduro 7y ago
        While its true SARS-CoV-2 is a virus, opportunistic bacterial pneumonia is a secondary complication of Covid19 which increases its lethality. So you need decent antibiotics too.
        radicalbyte 7y ago
        ..and it's nasty, my wife only just recovered from it a week ago after a total of 8 weeks in bed.
- emmelaich 7y ago
  Related, there's also the distinct possibility that many had Covid-19 well before it was in public consciousness. Look for ILI (Influenza-like Illness) stats which were appreciably higher in January. The obvious inference is that many had Covid-19 before it was recognised as such. This might be a good thing.
  - simonh 7y ago
    If that were true, we should see a much higher proportion of tested people showing positive. Also we shouldn't see the proportion of people tested being positive shooting up, but we do. Those ILI stats were probably just Flu.
    - mrfusion 7y ago
      I believe that most of the current testing only shows active infections?
      - simonh 7y ago
        Yes, and it has shown initially small numbers of active infections, growing rapidly, as a proportion of those tested. If the virus was already widely distributed, we would expect it to be much closer to equilibrium.
  - nemo44x 7y ago
    I think this is underrated. This thing must have been spreading since November here. I know a person who back in January acquired something like pneumonia and a bad fever, went to the hospital for awhile and tests were negative for flu, etc. doctors just didn’t know what it was. The person has COPD however. But anecdotally I’ve noticed quite a few more colleagues over the last few months out sick “with the flu or something”. No idea. They’re still only testing people with symptoms. We need a randomizes test and a test for antibodies to have any idea how much it has already spread. If it’s as contagious as they say and spreads in asymptotic people then why wouldn’t there be a significant population that has acquired and recovered from this? Many probably with very mild symptoms. I could just be in denial right now as well.
- xienze 7y ago
  Yeah I’m not sure what people are expecting to happen here. This virus has been circulating in the US for months and testing was limited. There’s surely many multiples of infected people than currently reported, and that’s true for any country that isn’t doing blanket testing of entire population.
  - mynegation 7y ago
    Even if that (EDIT: ‘that’ being an idea that virus has been circulating for months) were true (which almost certainly it is not), so what? The only logical explanation for this is that percentage of severe cases relative to totally susceptible and infected is orders of magnitude lower, and now the total number of infected is so large that number of severe cases is starting to get noticeable. But that is not the picture we are getting from South Korea that had much more comprehensive testinG.
    - xienze 7y ago
      > Even if that were true (which almost certainly it is not) What are you referring to? You don’t think the virus is already much more widespread in the US than currently reported numbers? I’m just making the observation that perhaps the large increases in US cases are more indicative of confirmation of already existing cases rather than necessarily being _new_ cases.
      - mynegation 7y ago
        I am not arguing that virus is more widespread than the reported numbers, that much is obvious. I was replying to the idea that virus has been circulating “for months” undetected. With a doubling time of 5 days or so, with “for months” circulation we would be in a totally different territory right now.
        xienze 7y ago
        > I was replying to the idea that virus has been circulating “for months” undetected. I don’t think that’s crazy at all. We had our first case sometime in January, and only until very very recently have we had any significant travel restrictions. It’s very contagious and for a significant number of people there are no real symptoms, or if there are, nothing life threatening. I don’t think it’s crazy at all that it’s been working it’s way around the US population for months. Maybe to put it another way, if we could instantly test al 300+M Americans right this instant, would you be surprised if say 20M or so tested positive or had had it?
TheOtherHobbes 7y ago
Yes - absolute criminal negligence in the US and UK. Possibly Australia too. The problem isn't just that a lot of people will die because the health system is swamped. That's hardly good news, but when you have a high peak you have a lot of people ill at the same time. And that means you run the risk of losing a significant percentage of critical workers in essential services including food, utilities, logistics, and IT. Some will die, some will "just" be very ill and unable to work for 2-4 weeks. If you're lucky the numbers of seriously ill will be low enough to keep things running. Beyond that you're on a scale from frightening inconvenience and breakdown in some locations to the economic equivalent of critical organ failure. Pushing any country through this is a huge and utterly irresponsible risk.
- throwaway_pdp09 7y ago
  Original poster. I'm from the UK. Looking at the curves only and leaving out politics completely, the UK curve is by far the slowest growing of the 3, for whatever reason. It's the US that has the most to fear at this point, of the 3 countries.
  - acqq 7y ago
    UK number of deaths is two weeks behind Italy's. I'm quite sure that that growth will be consistent in the next two weeks in the UK -- namely, up to now, the growth characteristic remained the same across the countries with different policies, and it can be observed, from China and Italy, how long it takes for any policy to decrease the growth. Then check and compare the Italian measures with the UK for your estimate when the UK curve will flatten in the weeks that follow. When the flattening will start will indeed make a huge difference in the direct impact of the virus (the number of ill and dead) between the countries, due to the growth characteristics being what they are. Also see my other posts. The number of "cases" reflects at the moment the capabilities of the whole medical system in each country (it's dependent on who is selected to be tested at all) and the tests used. The number of deaths hides less. Also, even if the specific numbers can't be compared 1 to 1 across the countries, the characteristics of the curves can. The growth is fast but it is comparable, and the measures take time to affect it.
  - 7y ago
mft_ 7y ago
Worth linking to this page, which is regularly updated with the sort of analyses you refer to: http://nrg.cs.ucl.ac.uk/mjh/covid19/ http://nrg.cs.ucl.ac.uk/mjh/covid19/ Scary that the US (especially some areas) and Switzerland are starting to track above Italy: http://nrg.cs.ucl.ac.uk/mjh/covid19/20mar2020/covid-us-norm.png http://nrg.cs.ucl.ac.uk/mjh/covid19/20mar2020/covid-us-norm....
- deleted 7y ago
  [deleted]
hef19898 7y ago
To answer your last question, yes it is irresponsible.
- okareaman 7y ago
  It would be irresponsible of him to show us his math?
cowsandmilk 7y ago
> the USA curve is fearsomely steep This analysis is difficult because it is related to testing capacity. We all know testing capacity was limited early on. It remains limited, but is growing. The faster capacity grows, the steeper the curve will be. Want to have a less steep curve? Lower the amount of testing. In another comment, you claim looking at the curves leaves out politics completely, but it doesn't. Any politician can make the situation look worse on the curve, but better serve their people, by increasing testing. They can also make their curve look better, but do worse for their people, by claiming their state is unable to purchase tests. This can be a very political game.
- notahacker 7y ago
  Yep. Ventilator usage [if available] and deaths are more reliable indicators, but they're also lagging ones [and even deaths aren't entirely consistently measured since many of the most severely affected patients exhibit comorbities, and many nations don't test the dead]
  - rzzzt 7y ago
    Others do, and that skews the results as well (at the very least, it makes numbers incomparable).
  - paganel 7y ago
    > deaths are more reliable indicators They are more reliable than the simple number of cases but in the Italian province of Bergamo (and I suppose in neighbouring Brescia, too) lots of people have started dying before the ambulance even arrives at their homes. Those people will not show up on the official statistics of covid victims, at least not now. A similar thing had started happening in Wuhan once the situation had become really dire, and the closest valid indicator people could find was to look at the number of incinerators and how busy they were (mostly looking at the number, because the incinerators were busy 24/7 anyway).
- tobltobs 7y ago
  > Want to have a less steep curve? Lower the amount of testing. That works only at the beginning.
acqq 7y ago
If you want to have better comparable values, you should account that US have had too little testing and it just starts to increase. The US also has such health care system that it doesn't treat most potential patients the same, also potentially missing the cases completely. So the numbers of the "confirmed cases" in the US aren't to be trusted at the moment. What's more sure, in most of the countries in the world, is that if the tests are available at all, and the patients happen to be admitted to the hospitals with the symptoms, they will be tested, and the percentage of deaths will be comparable in all countries, and we should be able to assume that the hospitals will report the deaths of the patients tested positive. In short, now that the numbers of deaths increase, these numbers reflect better the issues we are facing than just the reported cases. We should estimate the number of "comparable" cases across the countries or areas with different capabilities from the numbers of deaths, at least for the countries and areas which have at least enough tests to test those admitted with symptoms and report the dead, and once these numbers aren't too low to be too noisy. I've demonstrated some of my simple calculations in my other messages, so you can check these too.
DyslexicAtheist 7y ago
> if I'm right the US is going to be reeling in just a few day. considering how the UK handles the crisis it won't be far behind the US either.
mnl 7y ago
It is not an exponential, it's a logistic curve, just approximate with the SIS model, it's easier. Yeah I knew by Sunday that tomorrow we're hitting 30,000 cases in Spain. My assumptions worked. And it's just the tip, because I don't know anything about whether there's been randomized sampling, so who knows about the normalization. I just can't believe this. No one listens and this is in-your-face obvious.
- throwaway_pdp09 7y ago
  I realise it's actually a sigmoid but an early decent approximation is an exponential, no? (edit: good catch though)
  - mnl 7y ago
    Apparently not with this when you're early. I took it seriously when a third degree polynomial fit worked too well and then suddenly didn't.
    - throwaway_pdp09 7y ago
      OK, looking at this, the curve is upwards without inflection. What would you expect to get if you fitted a D3 poly to it? Why would you even try? Serious Q.
      - mnl 7y ago
        First thing you do is try to make sense of the data, if I can model 15 points with 2, 3, 4 parameters and further ones don't add any improvement I'm onto something. I've always done polynomials first, you can see if there's something much simpler than Lagrange interpolation, which in my experience means you have to go straight to the literature about that kind of problem. (Of course this works as long as you aren't seeing any peaks) oefrha, for some reason I can't reply to your comment just yet so I'll post it here: Of course. This is just my own criterion when I start with a bunch of data I know nothing about. Is there a complicated law behind them or maybe not? Am I seeing noise or there's a signal? You can fit anything smooth with a low order polynomial, so maybe there's a differentiable function right in front of you. It's just something I do and if you see no reason for it I might even agree with you on that. It never ends up in the model, though. It's just something I find useful at a preliminary stage. OK, We're not being responsible doing this and I'm not qualified to do it. I just have been fitting the data and maybe I've been lucky and I'm just an idiot. Having said that, this is also my problem, I have right now a hotspot in the vicinity and I'm worried. I just want to have a quantitative idea of what's going on. Now it's your job as experts to explain what's going on to the politicians and make sure they hear and they can do the right thing. I wouldn't be worried if the messages had matched the numbers when this started, they didn't. At some point we need someone to tell us "we're at this point and tomorrow we'll be at that point". I shouldn't feel compelled to find out by myself what all this is about. I feel awful by posting all this, I'm perfectly aware that non-experts in a field spout nonsense, but this is a very nonsensical situation and I'm tired of hearing we've been doing fine.
andrepd 7y ago
>I've been graphing the exp curve As you can imagine, there's more to epidemiology than this. I'm a big fan of letting the qualified people do their work, while we do ours: shut up and do not spread misinformation. In fact, at the risk of being rude ill even go so far and say that it's quite arrogant to pretend to pontificate about this when your knowledge about this issue is 0, and also when one major problem in combating this pandemic is the "epidemic of misinformation".
- jordinl 7y ago
  Who are these experts you speak of? Are they in US? UK? Italy? Spain?
  - leetrout 7y ago
    Some US specific data is at https://covidactnow.org/ https://covidactnow.org/
  - deleted 7y ago
    [deleted]
  - pinkfoot 7y ago
    China
- DyslexicAtheist 7y ago
  counter points: Many doctors lack training in epidemiology. Many epidemiologists aren't actual doctors. Healthcare in general is horrible with generating accurate raw data (JHU data comes often from scraping websites and the CDC itself has stopped publishing number of daily tests weeks ago). <-- this in fact is a technical problem not a medical one! You don't have to be a Dr. med in order to see gaps and problems with statistics and a large part of the conjecturing actually comes from gaps and flaws in the sources and the way data is presented. A background in an isolated discipline (only med, only statistics, only Math, etc) is not enough to harness and make sense of complexity. Finally research papers themselves are all pre-print and not peer-reviewed which is a trade-off in accuracy for speed. We're all finding solutions as we go and the more eye-balls from different discipline this gets, the better the outcome!
Lewton 7y ago
You have to bear in mind when doing any analysis of this that you shouldn’t treat the US as one country when comparing to Italy. The number of distinct outbreaks happening at once makes a big difference in the steepness of the curve in the beginning. Italy might have been 5-20 distinct outbreaks while what’s happening in the US looks much more like 50-100 separate outbreaks developing at once
- acqq 7y ago
  > The number of distinct outbreaks happening at once makes a big difference in the steepness of the curve in the beginning. How come? "Distinct outbreaks" just means the older state was underdiagnosed, not that the characteristics of the pandemics change.
  - Lewton 7y ago
    "Beginning" might be the wrong term, as it's a bit into the beginning that it starts to make a difference. Local saturation happens fairly quickly. Having 100 infected in one place is very much different to having 1 infection happening 100 different places when you look at it after a week When you're looking at the "country" view, the "older state" gets lost in the transmissions happening from people crossing borders. So what I mean is, people have been flying back to the states with infections spread out over the entire country while cross-border spread has been much more localized in italy
    - throwaway_pdp09 7y ago
      Oh my. Thanks for that explanation. Given the indifference of the US administration it suggests things may be spreading even faster over there than I realised. We'll know in a week or so.
    - acqq 7y ago
      > people have been flying back to the states with infections spread out over the entire country while cross-border spread has been much more localized in italy I still don't see the difference? Why do you think that the cross-border movement of the disease should be different in Europe compared to the US? Why do you think that the US should be worse off, if that is your point? Do you think people more fly back to the US compared to the people moving from country to country recently in Europe in the last period (including Italy)? Are you aware of how Europe functioned up to now? Many people worked in other countries, and they typically don't even have to fly to achieve that, especially not across the ocean.
stjohnswarts 7y ago
You're basing your curve off faulty data. We haven't been doing testing so we don't really know. Until a week ago no one was doing anything about it and staying home like they are now. Again that will vastly throw off your curve. It's still too early. Give it a week and re-run your model.
smileysteve 7y ago
Yesterday's evening jump was unexpected. We jumped yesterday, instead of 1.5x the day before, all of the way to 2x.n If 10k is the new baseline and we return back to 1.5x we're going to exceed Italy in cases by Monday and exceed China by Wednesday. Then, I fear, St Patrick's day partiers will only be measured by next Wednesday; 5 days incubation + 5 days to have test results.
chris_f 7y ago
One hopefully positive indicator is that yesterday new daily deaths in the US were lower than the day before (49 vs 57) [0]. Obviously it's only one day so time will tell if that means anything or a pattern occurs. As others have said, the stats for number of people affected is so closely linked to testing rates which have been increasing that this could be a more indicative metric to follow. [0] https://www.worldometers.info/coronavirus/country/us/ https://www.worldometers.info/coronavirus/country/us/
- marvin 7y ago
  I'm sorry to say it, but that's just noise in the data. The death numbers in the United States will follow an exponential curve for a long time yet. Two weeks would be the absolute minimum before the shutdowns have an effect, but I think a month or two is a more realistic hope.
mrfusion 7y ago
Keep in mind that all the actions we’ve taken won’t show up for 14 days or longer since the already infected take time to show up.
ComputerGuru 7y ago
The numbers mean nothing. All your seeing is the availability of testing kits, which has nothing to do with the number of infections. Don’t bother graphing a thing. For the numbers to have meaning, a stochastic sample of the population should be tested at random, not people coming forward because they think they’re sick.

Wowfunhappy 7y ago

But how much of the US’s growth is due to us finally having some (albeit not enough) testing?

throwaway_pdp09 7y ago
Good question, I don't know. If it helps, a quick search got this https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/testing-in-us.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Ftesting-in-us.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/test... See table at bottom.
tyingq 7y ago
That's a very good point, and the lack of tests had a secondary effect. Nobody here took it very seriously at first, because the numbers were very low.
simonh 7y ago
This is key. We really can't compare countries confirmed case numbers directly because they are operating very different testing programmes. Just look at Germany. More confirmed cases than the USA, but a quarter of the deaths. Germany also has 80% as many cases as Spain, but about 5% as many deaths. All that, without a severe lockdown. Clearly something completely different is going on there than in many other countries, and it seems they have an extremely effective and well organised testing system. They're testing about 160,000 people a week. In comparison, the UK to date has only tested around 50,000 people in total so no wonder our case numbers are far lower, even though we have double the number of deaths. So Germany is an outlier, but it just goes to show even for other countries you can't just compare the curves and draw any definitive conclusions without also looking at the testing regime. This is where the experts with their detailed population models and simulation tools come in.
- hallohallohallo 7y ago
  It is the health care system like number of ICUs, training of doctors and stuff like not being able to get antibiotics simply over the counter like in Italy. If my memory serves me right e.g. in Italy 29% have a resistance to antibiotics, in Germany only 0.4%.
  - simonh 7y ago
    People don't become resistant to antibiotics, bacteria do and resistant bacteria in Italy would just spread to Germany. Anyway Covid-19 is a virus, not a bacterium.
    - guiriduro 7y ago
      While its true SARS-CoV-2 is a virus, opportunistic bacterial pneumonia is a secondary complication of Covid19 which increases its lethality. So you need decent antibiotics too.
      - radicalbyte 7y ago
        ..and it's nasty, my wife only just recovered from it a week ago after a total of 8 weeks in bed.
emmelaich 7y ago
Related, there's also the distinct possibility that many had Covid-19 well before it was in public consciousness. Look for ILI (Influenza-like Illness) stats which were appreciably higher in January. The obvious inference is that many had Covid-19 before it was recognised as such. This might be a good thing.
- simonh 7y ago
  If that were true, we should see a much higher proportion of tested people showing positive. Also we shouldn't see the proportion of people tested being positive shooting up, but we do. Those ILI stats were probably just Flu.
  - mrfusion 7y ago
    I believe that most of the current testing only shows active infections?
    - simonh 7y ago
      Yes, and it has shown initially small numbers of active infections, growing rapidly, as a proportion of those tested. If the virus was already widely distributed, we would expect it to be much closer to equilibrium.
- nemo44x 7y ago
  I think this is underrated. This thing must have been spreading since November here. I know a person who back in January acquired something like pneumonia and a bad fever, went to the hospital for awhile and tests were negative for flu, etc. doctors just didn’t know what it was. The person has COPD however. But anecdotally I’ve noticed quite a few more colleagues over the last few months out sick “with the flu or something”. No idea. They’re still only testing people with symptoms. We need a randomizes test and a test for antibodies to have any idea how much it has already spread. If it’s as contagious as they say and spreads in asymptotic people then why wouldn’t there be a significant population that has acquired and recovered from this? Many probably with very mild symptoms. I could just be in denial right now as well.
xienze 7y ago
Yeah I’m not sure what people are expecting to happen here. This virus has been circulating in the US for months and testing was limited. There’s surely many multiples of infected people than currently reported, and that’s true for any country that isn’t doing blanket testing of entire population.
- mynegation 7y ago
  Even if that (EDIT: ‘that’ being an idea that virus has been circulating for months) were true (which almost certainly it is not), so what? The only logical explanation for this is that percentage of severe cases relative to totally susceptible and infected is orders of magnitude lower, and now the total number of infected is so large that number of severe cases is starting to get noticeable. But that is not the picture we are getting from South Korea that had much more comprehensive testinG.
  - xienze 7y ago
    > Even if that were true (which almost certainly it is not) What are you referring to? You don’t think the virus is already much more widespread in the US than currently reported numbers? I’m just making the observation that perhaps the large increases in US cases are more indicative of confirmation of already existing cases rather than necessarily being _new_ cases.
    - mynegation 7y ago
      I am not arguing that virus is more widespread than the reported numbers, that much is obvious. I was replying to the idea that virus has been circulating “for months” undetected. With a doubling time of 5 days or so, with “for months” circulation we would be in a totally different territory right now.
      - xienze 7y ago
        > I was replying to the idea that virus has been circulating “for months” undetected. I don’t think that’s crazy at all. We had our first case sometime in January, and only until very very recently have we had any significant travel restrictions. It’s very contagious and for a significant number of people there are no real symptoms, or if there are, nothing life threatening. I don’t think it’s crazy at all that it’s been working it’s way around the US population for months. Maybe to put it another way, if we could instantly test al 300+M Americans right this instant, would you be surprised if say 20M or so tested positive or had had it?

TheOtherHobbes 7y ago

Yes - absolute criminal negligence in the US and UK. Possibly Australia too. The problem isn't just that a lot of people will die because the health system is swamped. That's hardly good news, but when you have a high peak you have a lot of people ill at the same time. And that means you run the risk of losing a significant percentage of critical workers in essential services including food, utilities, logistics, and IT. Some will die, some will "just" be very ill and unable to work for 2-4 weeks. If you're lucky the numbers of seriously ill will be low enough to keep things running. Beyond that you're on a scale from frightening inconvenience and breakdown in some locations to the economic equivalent of critical organ failure. Pushing any country through this is a huge and utterly irresponsible risk.

throwaway_pdp09 7y ago
Original poster. I'm from the UK. Looking at the curves only and leaving out politics completely, the UK curve is by far the slowest growing of the 3, for whatever reason. It's the US that has the most to fear at this point, of the 3 countries.
- acqq 7y ago
  UK number of deaths is two weeks behind Italy's. I'm quite sure that that growth will be consistent in the next two weeks in the UK -- namely, up to now, the growth characteristic remained the same across the countries with different policies, and it can be observed, from China and Italy, how long it takes for any policy to decrease the growth. Then check and compare the Italian measures with the UK for your estimate when the UK curve will flatten in the weeks that follow. When the flattening will start will indeed make a huge difference in the direct impact of the virus (the number of ill and dead) between the countries, due to the growth characteristics being what they are. Also see my other posts. The number of "cases" reflects at the moment the capabilities of the whole medical system in each country (it's dependent on who is selected to be tested at all) and the tests used. The number of deaths hides less. Also, even if the specific numbers can't be compared 1 to 1 across the countries, the characteristics of the curves can. The growth is fast but it is comparable, and the measures take time to affect it.
- 7y ago

mft_ 7y ago

Worth linking to this page, which is regularly updated with the sort of analyses you refer to: http://nrg.cs.ucl.ac.uk/mjh/covid19/ http://nrg.cs.ucl.ac.uk/mjh/covid19/ Scary that the US (especially some areas) and Switzerland are starting to track above Italy: http://nrg.cs.ucl.ac.uk/mjh/covid19/20mar2020/covid-us-norm.png http://nrg.cs.ucl.ac.uk/mjh/covid19/20mar2020/covid-us-norm....

deleted 7y ago
[deleted]

hef19898 7y ago

To answer your last question, yes it is irresponsible.

okareaman 7y ago
It would be irresponsible of him to show us his math?

cowsandmilk 7y ago

> the USA curve is fearsomely steep This analysis is difficult because it is related to testing capacity. We all know testing capacity was limited early on. It remains limited, but is growing. The faster capacity grows, the steeper the curve will be. Want to have a less steep curve? Lower the amount of testing. In another comment, you claim looking at the curves leaves out politics completely, but it doesn't. Any politician can make the situation look worse on the curve, but better serve their people, by increasing testing. They can also make their curve look better, but do worse for their people, by claiming their state is unable to purchase tests. This can be a very political game.

notahacker 7y ago
Yep. Ventilator usage [if available] and deaths are more reliable indicators, but they're also lagging ones [and even deaths aren't entirely consistently measured since many of the most severely affected patients exhibit comorbities, and many nations don't test the dead]
- rzzzt 7y ago
  Others do, and that skews the results as well (at the very least, it makes numbers incomparable).
- paganel 7y ago
  > deaths are more reliable indicators They are more reliable than the simple number of cases but in the Italian province of Bergamo (and I suppose in neighbouring Brescia, too) lots of people have started dying before the ambulance even arrives at their homes. Those people will not show up on the official statistics of covid victims, at least not now. A similar thing had started happening in Wuhan once the situation had become really dire, and the closest valid indicator people could find was to look at the number of incinerators and how busy they were (mostly looking at the number, because the incinerators were busy 24/7 anyway).
tobltobs 7y ago
> Want to have a less steep curve? Lower the amount of testing. That works only at the beginning.

acqq 7y ago

If you want to have better comparable values, you should account that US have had too little testing and it just starts to increase. The US also has such health care system that it doesn't treat most potential patients the same, also potentially missing the cases completely. So the numbers of the "confirmed cases" in the US aren't to be trusted at the moment. What's more sure, in most of the countries in the world, is that if the tests are available at all, and the patients happen to be admitted to the hospitals with the symptoms, they will be tested, and the percentage of deaths will be comparable in all countries, and we should be able to assume that the hospitals will report the deaths of the patients tested positive. In short, now that the numbers of deaths increase, these numbers reflect better the issues we are facing than just the reported cases. We should estimate the number of "comparable" cases across the countries or areas with different capabilities from the numbers of deaths, at least for the countries and areas which have at least enough tests to test those admitted with symptoms and report the dead, and once these numbers aren't too low to be too noisy. I've demonstrated some of my simple calculations in my other messages, so you can check these too.

DyslexicAtheist 7y ago

> if I'm right the US is going to be reeling in just a few day. considering how the UK handles the crisis it won't be far behind the US either.

mnl 7y ago

It is not an exponential, it's a logistic curve, just approximate with the SIS model, it's easier. Yeah I knew by Sunday that tomorrow we're hitting 30,000 cases in Spain. My assumptions worked. And it's just the tip, because I don't know anything about whether there's been randomized sampling, so who knows about the normalization. I just can't believe this. No one listens and this is in-your-face obvious.

throwaway_pdp09 7y ago
I realise it's actually a sigmoid but an early decent approximation is an exponential, no? (edit: good catch though)
- mnl 7y ago
  Apparently not with this when you're early. I took it seriously when a third degree polynomial fit worked too well and then suddenly didn't.
  - throwaway_pdp09 7y ago
    OK, looking at this, the curve is upwards without inflection. What would you expect to get if you fitted a D3 poly to it? Why would you even try? Serious Q.
    - mnl 7y ago
      First thing you do is try to make sense of the data, if I can model 15 points with 2, 3, 4 parameters and further ones don't add any improvement I'm onto something. I've always done polynomials first, you can see if there's something much simpler than Lagrange interpolation, which in my experience means you have to go straight to the literature about that kind of problem. (Of course this works as long as you aren't seeing any peaks) oefrha, for some reason I can't reply to your comment just yet so I'll post it here: Of course. This is just my own criterion when I start with a bunch of data I know nothing about. Is there a complicated law behind them or maybe not? Am I seeing noise or there's a signal? You can fit anything smooth with a low order polynomial, so maybe there's a differentiable function right in front of you. It's just something I do and if you see no reason for it I might even agree with you on that. It never ends up in the model, though. It's just something I find useful at a preliminary stage. OK, We're not being responsible doing this and I'm not qualified to do it. I just have been fitting the data and maybe I've been lucky and I'm just an idiot. Having said that, this is also my problem, I have right now a hotspot in the vicinity and I'm worried. I just want to have a quantitative idea of what's going on. Now it's your job as experts to explain what's going on to the politicians and make sure they hear and they can do the right thing. I wouldn't be worried if the messages had matched the numbers when this started, they didn't. At some point we need someone to tell us "we're at this point and tomorrow we'll be at that point". I shouldn't feel compelled to find out by myself what all this is about. I feel awful by posting all this, I'm perfectly aware that non-experts in a field spout nonsense, but this is a very nonsensical situation and I'm tired of hearing we've been doing fine.

andrepd 7y ago

>I've been graphing the exp curve As you can imagine, there's more to epidemiology than this. I'm a big fan of letting the qualified people do their work, while we do ours: shut up and do not spread misinformation. In fact, at the risk of being rude ill even go so far and say that it's quite arrogant to pretend to pontificate about this when your knowledge about this issue is 0, and also when one major problem in combating this pandemic is the "epidemic of misinformation".

jordinl 7y ago
Who are these experts you speak of? Are they in US? UK? Italy? Spain?
- leetrout 7y ago
  Some US specific data is at https://covidactnow.org/ https://covidactnow.org/
- deleted 7y ago
  [deleted]
- pinkfoot 7y ago
  China
DyslexicAtheist 7y ago
counter points: Many doctors lack training in epidemiology. Many epidemiologists aren't actual doctors. Healthcare in general is horrible with generating accurate raw data (JHU data comes often from scraping websites and the CDC itself has stopped publishing number of daily tests weeks ago). <-- this in fact is a technical problem not a medical one! You don't have to be a Dr. med in order to see gaps and problems with statistics and a large part of the conjecturing actually comes from gaps and flaws in the sources and the way data is presented. A background in an isolated discipline (only med, only statistics, only Math, etc) is not enough to harness and make sense of complexity. Finally research papers themselves are all pre-print and not peer-reviewed which is a trade-off in accuracy for speed. We're all finding solutions as we go and the more eye-balls from different discipline this gets, the better the outcome!

Lewton 7y ago

You have to bear in mind when doing any analysis of this that you shouldn’t treat the US as one country when comparing to Italy. The number of distinct outbreaks happening at once makes a big difference in the steepness of the curve in the beginning. Italy might have been 5-20 distinct outbreaks while what’s happening in the US looks much more like 50-100 separate outbreaks developing at once

acqq 7y ago
> The number of distinct outbreaks happening at once makes a big difference in the steepness of the curve in the beginning. How come? "Distinct outbreaks" just means the older state was underdiagnosed, not that the characteristics of the pandemics change.
- Lewton 7y ago
  "Beginning" might be the wrong term, as it's a bit into the beginning that it starts to make a difference. Local saturation happens fairly quickly. Having 100 infected in one place is very much different to having 1 infection happening 100 different places when you look at it after a week When you're looking at the "country" view, the "older state" gets lost in the transmissions happening from people crossing borders. So what I mean is, people have been flying back to the states with infections spread out over the entire country while cross-border spread has been much more localized in italy
  - throwaway_pdp09 7y ago
    Oh my. Thanks for that explanation. Given the indifference of the US administration it suggests things may be spreading even faster over there than I realised. We'll know in a week or so.
  - acqq 7y ago
    > people have been flying back to the states with infections spread out over the entire country while cross-border spread has been much more localized in italy I still don't see the difference? Why do you think that the cross-border movement of the disease should be different in Europe compared to the US? Why do you think that the US should be worse off, if that is your point? Do you think people more fly back to the US compared to the people moving from country to country recently in Europe in the last period (including Italy)? Are you aware of how Europe functioned up to now? Many people worked in other countries, and they typically don't even have to fly to achieve that, especially not across the ocean.

stjohnswarts 7y ago

You're basing your curve off faulty data. We haven't been doing testing so we don't really know. Until a week ago no one was doing anything about it and staying home like they are now. Again that will vastly throw off your curve. It's still too early. Give it a week and re-run your model.

smileysteve 7y ago

Yesterday's evening jump was unexpected. We jumped yesterday, instead of 1.5x the day before, all of the way to 2x.n If 10k is the new baseline and we return back to 1.5x we're going to exceed Italy in cases by Monday and exceed China by Wednesday. Then, I fear, St Patrick's day partiers will only be measured by next Wednesday; 5 days incubation + 5 days to have test results.

chris_f 7y ago

One hopefully positive indicator is that yesterday new daily deaths in the US were lower than the day before (49 vs 57) [0]. Obviously it's only one day so time will tell if that means anything or a pattern occurs. As others have said, the stats for number of people affected is so closely linked to testing rates which have been increasing that this could be a more indicative metric to follow. [0] https://www.worldometers.info/coronavirus/country/us/ https://www.worldometers.info/coronavirus/country/us/

marvin 7y ago
I'm sorry to say it, but that's just noise in the data. The death numbers in the United States will follow an exponential curve for a long time yet. Two weeks would be the absolute minimum before the shutdowns have an effect, but I think a month or two is a more realistic hope.

mrfusion 7y ago

Keep in mind that all the actions we’ve taken won’t show up for 14 days or longer since the already infected take time to show up.

ComputerGuru 7y ago

The numbers mean nothing. All your seeing is the availability of testing kits, which has nothing to do with the number of infections. Don’t bother graphing a thing. For the numbers to have meaning, a stochastic sample of the population should be tested at random, not people coming forward because they think they’re sick.