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 12 Nov 2019

      But then, a further 7 were excluded because of 'poor hydration compliance' What does this mean? Essentially, the researchers thought they were drinking more/less water than their experimental conditionpic.twitter.com/PJXeqv0IG5

      1 reply 0 retweets 1 like
      Show this thread
    2. Health Nerd‏Verified account @GidMK 12 Nov 2019

      Now, this makes the study what's known as a per-protocol analysis Without going into the details, per-protocol analyses are KNOWN for giving spurious/misleading resultspic.twitter.com/o2G7Yissgq

      1 reply 0 retweets 4 likes
      Show this thread
    3. Health Nerd‏Verified account @GidMK 12 Nov 2019

      But there's more - after excluding participants entirely, the study excluded between 5 and 21 children from each analysis in the study That's up to 28% of the remaining sample (!)pic.twitter.com/j0KfldJaV2

      1 reply 0 retweets 3 likes
      Show this thread
    4. Health Nerd‏Verified account @GidMK 12 Nov 2019

      This was due to "poor cognitive data" What does that mean? Well, according to the study, it means that these kids had results that were considered 'outliers' or 'poor performance'pic.twitter.com/70Z3ZHH8rl

      1 reply 0 retweets 2 likes
      Show this thread
    5. Health Nerd‏Verified account @GidMK 12 Nov 2019

      Astute readers will note that this means that apparently 8/64 (13%!) of the children had results more than 3 standard deviations from the mean in the go/no-go task That seems...unlikely

      2 replies 0 retweets 3 likes
      Show this thread
    6. Health Nerd‏Verified account @GidMK 12 Nov 2019

      To give you an idea of how unlikely, I ran the mean/standard deviations through SPRITE (thanks @sTeamTraen @jamesheathers) for 100 repetitions, and didn't get a single distribution with more than 3% of results >3 SDs from the mean So...maybe possible? VERY weird

      2 replies 0 retweets 5 likes
      Show this thread
    7. Health Nerd‏Verified account @GidMK 12 Nov 2019

      (Check out SPRITE here https://peerj.com/preprints/26968v1/ …)

      1 reply 0 retweets 0 likes
      Show this thread
    8. Health Nerd‏Verified account @GidMK 12 Nov 2019

      Also, if you look at the children that they excluded for "poor hydration compliance", they talk about an "a priori" defined criteria for exclusion This is something that you'd usually declare in your pre-registration. Let's check their's outpic.twitter.com/fcNm4YsOfG

      1 reply 0 retweets 1 like
      Show this thread
    9. Health Nerd‏Verified account @GidMK 12 Nov 2019

      The pre-registration is...not great Firstly, no a priori exclusion criteria for urinary values. That's a problem, because it means that we have no way of knowing if the study authors decided to exclude these 7 children before the study or after looking at the results 😕pic.twitter.com/ipMm6CPCPJ

      1 reply 0 retweets 3 likes
      Show this thread
    10. Health Nerd‏Verified account @GidMK 12 Nov 2019

      But there's more! The pre-registration completely contradicts the study protocol in numerous ways😮 The number of participants, age brackets, intervention arm protocol, inclusion/exclusion criteria, testing schedule, and outcome measures are different! That's worrying

      1 reply 0 retweets 3 likes
      Show this thread
      Health Nerd‏Verified account @GidMK 12 Nov 2019

      It almost sounds like a completely different trial, but the authors and name/number are the same You can compare the pre-reg to the study here:https://clinicaltrials.gov/ct2/show/record/NCT02816450?term=NCT02816450&draw=2&rank=1 …

      6:33 PM - 12 Nov 2019
      • 1 Like
      • James Pitt
      1 reply 0 retweets 1 like
        1. New conversation
        2. Health Nerd‏Verified account @GidMK 12 Nov 2019

          So, after all of this, what did the study find? Hilariously, there was NO EFFECT of water intake (AL/Low/High) on any cognitive test!!!!pic.twitter.com/kC75Y16GdT

          1 reply 0 retweets 2 likes
          Show this thread
        3. Health Nerd‏Verified account @GidMK 12 Nov 2019

          In other words, the PRIMARY FINDINGS of this research project is that drinking more/less water DOESN'T IMPACT CHILDREN'S PERFORMANCE ON COGNITIVE TASKS That's the exact opposite of what the media reportedpic.twitter.com/uaa7gSlEpu

          1 reply 0 retweets 5 likes
          Show this thread
        4. Health Nerd‏Verified account @GidMK 12 Nov 2019

          What they DID find, and what was then converted into the headlines, was that if you look WITHIN GROUPS, there were some statistically significant trends, where better urine markers of hydration led to better accuracy on the testspic.twitter.com/8m5mwUGbVF

          1 reply 0 retweets 2 likes
          Show this thread
        5. Health Nerd‏Verified account @GidMK 12 Nov 2019

          I.e. if you look just at kids when they were in the AL condition (drinking as much water as they wanted), those who had more concentrated urine appeared to be slightly less accurate on some cognitive tests

          1 reply 0 retweets 1 like
          Show this thread
        6. Health Nerd‏Verified account @GidMK 12 Nov 2019

          But remember - there was no difference between conditions In other words, perhaps dehydration affects cognition, but drinking more/less water doesn't appear to make any difference

          1 reply 1 retweet 4 likes
          Show this thread
        7. Health Nerd‏Verified account @GidMK 12 Nov 2019

          Here's the main table of results As you can see, there are really very few differences between the three groups on any test for reaction time or accuracypic.twitter.com/jdzJ4do8AH

          1 reply 0 retweets 2 likes
          Show this thread
        8. Health Nerd‏Verified account @GidMK 12 Nov 2019

          Moreover, it's very hard to tell if the statistical tests were controlled for multiple comparisons, which is concerning because many of the p-values were between 0.03-0.05pic.twitter.com/kCMktXnc3t

          1 reply 0 retweets 3 likes
          Show this thread
        9. Health Nerd‏Verified account @GidMK 12 Nov 2019

          And, reminder, this was an industry-funded trial, which makes the reporting of the apparently negative findings even more worrying

          1 reply 0 retweets 1 like
          Show this thread
        10. Health Nerd‏Verified account @GidMK 12 Nov 2019

          Also worth noting that the study didn't really look at multitasking per se, this was based on an extrapolation from the within-group tests that looked at cognitive load!

          1 reply 0 retweets 0 likes
          Show this thread
        11. Health Nerd‏Verified account @GidMK 12 Nov 2019

          TO RECAP: - industry-funded trial - potential issues with study design - strange numbers - results NEGATIVE for primary outcome - didn't look at multitasking - somehow still reported as "water helps multitasking"

          1 reply 0 retweets 1 like
          Show this thread
        12. Health Nerd‏Verified account @GidMK 12 Nov 2019

          P.S. I forgot to mention that I don't think you can call a trial measuring low water intake to high water intake a trial of water It's a trial of dehydrationpic.twitter.com/g6Hv4gyR0h

          1 reply 0 retweets 3 likes
          Show this thread
        13. Health Nerd‏Verified account @GidMK 12 Nov 2019

          I mean, imagine measuring cognitive ability in people who hadn't eaten in days vs those who'd eaten plenty It's a ridiculous thing to test in the first place!

          2 replies 0 retweets 3 likes
          Show this thread
        14. 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