Skip to content
By using Twitter’s services you agree to our Cookies Use. We and our partners operate globally and use cookies, including for analytics, personalisation, and ads.
  • Home Home Home, current page.
  • About

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
GidMK's profile
Health Nerd
Health Nerd
Health Nerd
Verified account
@GidMK

Tweets

Health NerdVerified account

@GidMK

Epidemiologist. Writer (Guardian, Observer etc). "Well known research trouble-maker". PhDing at @UoW Host of @senscipod Email gidmk.healthnerd@gmail.com he/him

Sydney, New South Wales
theguardian.com/profile/gideon…
Joined November 2015

Tweets

  • © 2021 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Health Nerd‏Verified account @GidMK 14 Oct 2020

      14/n And there are new errors as well. In this study of blood donors in Rhode Island, the authors estimate a seropositivity of 0.6%, while the review paper has 3.9% insteadpic.twitter.com/MvF6e9Psgd

      1 reply 2 retweets 88 likes
      Show this thread
    2. Health Nerd‏Verified account @GidMK 14 Oct 2020

      15/n But by far and away, the biggest error in the text is simply to do with using clearly inappropriate samples to estimate population prevalence This is a fundamental flaw in the paper, and really something of a basic epidemiological mistake

      1 reply 10 retweets 139 likes
      Show this thread
    3. Health Nerd‏Verified account @GidMK 14 Oct 2020

      16/n Some of these studies are just so clearly inappropriate to infer a population estimate that it doesn't really require explaining. Samples of a single business in a city, or inpatient dialysis unitspic.twitter.com/CTWnw0Fbjf

      1 reply 9 retweets 102 likes
      Show this thread
    4. Health Nerd‏Verified account @GidMK 14 Oct 2020

      18/n Then we have blood donors, who again may give an erroneous result. These are people who, DURING A PANDEMIC are happy to go out and about and give blood. It is quite possible that they are MORE likely to have been infected than the general population!pic.twitter.com/0ME5x1br1B

      4 replies 5 retweets 101 likes
      Show this thread
    5. Health Nerd‏Verified account @GidMK 14 Oct 2020

      18.5/n There are also a lot of included studies from places in which there is almost certainly an enormous undercount of deaths For example, India, where the official death counts may represent a substantial underestimatehttps://www.bmj.com/content/370/bmj.m2859 …

      2 replies 11 retweets 91 likes
      Show this thread
    6. Health Nerd‏Verified account @GidMK 14 Oct 2020

      19/n A very basic, reasonable thing to do would be to conduct a sensitivity analysis excluding these biased estimates, to see what happens when you only use representative population estimates Which we can do

      1 reply 1 retweet 80 likes
      Show this thread
    7. Health Nerd‏Verified account @GidMK 14 Oct 2020

      20/n If we take the median of only these somewhat good-quality studies (some of them still aren't great, but at least they're not clearly inappropriate), we get a value of 0.5% Double the estimate of 0.27%pic.twitter.com/tQSICfngT9

      2 replies 13 retweets 111 likes
      Show this thread
    8. Health Nerd‏Verified account @GidMK 14 Oct 2020

      21/n I thought at this point I'd briefly look at blood donor studies, because they are an interesting case study The author argues that these should be included because, due to "healthy volunteer bias", at worse any estimate should bias the IFR results upwardspic.twitter.com/zfMeDdKKgn

      2 replies 2 retweets 59 likes
      Show this thread
    9. Health Nerd‏Verified account @GidMK 14 Oct 2020

      22/n Well, we can now actually test this theory and see if it is true. Enough studies have been done that we have COVID-19 seroprevalence estimates from BOTH blood donor studies AND representative samples and compare them

      1 reply 2 retweets 60 likes
      Show this thread
    10. Health Nerd‏Verified account @GidMK 14 Oct 2020

      23/n For example, in England an ongoing study on blood donors by PHE estimates that 8.5% of the population has developed antibodies to COVID-19 However, the ONS with their massive randomized study puts the figure at 6% insteadpic.twitter.com/ocnYbQoazk

      1 reply 3 retweets 70 likes
      Show this thread
      Health Nerd‏Verified account @GidMK 14 Oct 2020

      24/n In Denmark, a robust population estimate put the figure at 1.1%, while their blood donor study estimates 1.9% have been infected previouslypic.twitter.com/BT1eqgjtuT

      4:02 PM - 14 Oct 2020
      • 3 Retweets
      • 64 Likes
      • Jim Andrakakis ⚕️⚕️ Whitney R. Robinson eec DragonPharmD 💙 Anjo Joschka Meier Fabio Hasler Atomsk's Sanakan Michelle McKinley💙 Thank you NHS & all keyworkers
      4 replies 3 retweets 64 likes
        1. New conversation
        2. Health Nerd‏Verified account @GidMK 14 Oct 2020

          25/n Indeed, in every location where both a non-probabilistic, convenience sample has been taken (not just blood donors) AS WELL AS a well-done population estimate, the convenience sample overestimates the seroprevalence

          3 replies 4 retweets 91 likes
          Show this thread
        3. Health Nerd‏Verified account @GidMK 14 Oct 2020

          26/n We have a new paper that we're working on that suggests that using such estimates will usually overstate the true seroprevalence by a factor of about 2x Which means the true IFR would be double the number computed from such studies

          1 reply 4 retweets 74 likes
          Show this thread
        4. Health Nerd‏Verified account @GidMK 14 Oct 2020

          27/n There are also still, after many revisions, studies that have been excluded inappropriately from the estimates This study from Italy, for example, which produces an estimate of 7% (!) for IFR in the regionpic.twitter.com/41OGhRzSoN

          3 replies 3 retweets 63 likes
          Show this thread
        5. Health Nerd‏Verified account @GidMK 14 Oct 2020

          29/n Similarly, there are numerous country-wide efforts not looked at in any way, such as the large population studies conducted in Italy (150,000 participants) and Portugal (2,300 participants)pic.twitter.com/Ur07B0QRpM

          2 replies 1 retweet 56 likes
          Show this thread
        6. Health Nerd‏Verified account @GidMK 14 Oct 2020

          30/n And while there is a very brief discussion of the variation in IFR by region, the main component (age) - as we have demonstrated - was barely addressed, with the author instead focusing on vague speculation about healthcare systemshttps://www.medrxiv.org/content/10.1101/2020.07.23.20160895v6 …

          1 reply 1 retweet 59 likes
          Show this thread
        7. Health Nerd‏Verified account @GidMK 14 Oct 2020

          31/n We can actually see how age of those infected impacts IFR quite neatly from some of the studies in this review Qatar (0.01%) and Spain (1.15%) look very different, right?pic.twitter.com/kwAOJ4QzCX

          2 replies 2 retweets 63 likes
          Show this thread
        8. Health Nerd‏Verified account @GidMK 14 Oct 2020

          Health Nerd Retweeted Health Nerd

          32/n Wrong! In fact, the difference here is entirely explained by age! In Qatar, infections have mostly been limited to the immigrant worker population (<40 years), with this group representing more than 50% of infectionshttps://twitter.com/GidMK/status/1300938689535565824?s=20 …

          Health Nerd added,

          Health NerdVerified account @GidMK
          Replying to @Brian_Orak @greg_travis and 2 others
          Yes indeed, and actually this is quite well explained by our recent meta-analysis of IFR by age: https://www.medrxiv.org/content/10.1101/2020.07.23.20160895v4 … If you use the predicted IFRs here, Qatar is actually a touch higher than expected given that >50% of their infections are <40yo
          2 replies 3 retweets 82 likes
          Show this thread
        9. Health Nerd‏Verified account @GidMK 14 Oct 2020

          33/n Since this group is at a very low risk of death from COVID-19, the population IFR is MUCH lower than in Spain, where infections among the elderly have been much more common

          1 reply 2 retweets 42 likes
          Show this thread
        10. Health Nerd‏Verified account @GidMK 14 Oct 2020

          34/n All of these errors are a shame, because to a certain extent I agree with the author IFR is NOT a fixed category. In the metaregression linked above in the thread, we demonstrated that ~90% of variation in IFR between regions was probably due to the age of those infected!pic.twitter.com/fj0k5oyW2B

          2 replies 10 retweets 69 likes
          Show this thread
        11. Health Nerd‏Verified account @GidMK 14 Oct 2020

          35/n Unfortunately, Prof Ioannidis appears not to have read this study, but if you are interested here is the preprint version to perusehttps://www.medrxiv.org/content/10.1101/2020.07.23.20160895v6 …

          1 reply 3 retweets 57 likes
          Show this thread
        12. Health Nerd‏Verified account @GidMK 14 Oct 2020

          36/n Anyway, there are numerous errors remaining in the text that I haven't pointed out, but if you've reached this far in the thread I'm sure you're tired of me telling them to you straight up. Have a really careful look and see if you can find them!

          1 reply 0 retweets 40 likes
          Show this thread
        13. Health Nerd‏Verified account @GidMK 14 Oct 2020

          37/n (As a start, there is now a representative population estimate from Wuhan out that implies an IFR SUBSTANTIALLY lower than the ones inferred in this paper from samples including hospitalized patients)

          2 replies 0 retweets 36 likes
          Show this thread
        14. Health Nerd‏Verified account @GidMK 14 Oct 2020

          38/n Regardless, the main take-home remains, unfortunately, that this paper is overtly wrong in a number of ways, it does not adhere to even the most basic guidelines for this type of research, and thus the point estimate is probably wrong

          5 replies 6 retweets 74 likes
          Show this thread
        15. Health Nerd‏Verified account @GidMK 14 Oct 2020

          39/n Sorry, typo in tweet 37 - should read an IFR SUBSTANTIALLY *higher*, not lower. The SEROPREVALENCE is lower (at ~2%) which implies an IFR of ~1.2%

          3 replies 1 retweet 49 likes
          Show this thread
        16. Health Nerd‏Verified account @GidMK 14 Oct 2020

          40/n Oh, on an unrelated sidenote, it's quite funny that the author spends some time arguing that using a median is more appropriate than doing a R-E meta-analysis (as @LeaMerone and I did), so I quickly calculated the median for our study and it is higher at 0.79% for IFR 😂pic.twitter.com/QTkJKNzMnb

          12 replies 1 retweet 70 likes
          Show this thread
        17. End of conversation

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2021 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Cookies
        • Ads info