Thiago
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csthiago.bsky.social
Thiago
@csthiago.bsky.social
37 followers 85 following 65 posts
Methodologist/Epidemiologist
London - UK
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Reposted by Thiago
andrew.heiss.phd
Wrote up a little intervention post/explanation for my class about why using LLMs for trying to learn programming (as first time learners!) is bad and detrimental datavizf25.classes.andrewheiss.com/news/2025-11...
In the first week of class, I had you read an article about how ChatGPT is philosophical “bullshit”, as well as this other post about AI and LLMs in this class. I’ve seen a surprising increase in the amount of ChatGPT-based weekly check-ins and graph interpretations in the exercises. (In the past, I’ve even had students tell me they PDFs of the slides into ChatGPT to generate interesting and confusing things.) Don’t do this! LLMs cannot find three things that you personally found interesting from the readings. LLMs are not you. It’s a huge waste of time for all of us to for me to spend time evaluating and grading output from ChatGPT. I want to read what you think and do, not what a computer invents. NoteMy personal stance on AI and LLMs Many of you have asked about how I think about and use LLMs in my own work (and in the class materials). Please check this short little page where I explain what I do with text, images, code, research, and learning. In short, I do not use LLMs to create any of the materials for this class, and I do not use them to grade or evaluate any of your work. I’ve even had several students submit completely made up stuff for mini projects and final projects. In your final project, your job is to take a dataset, make three different plots with it, and combine the plots into one graphic that tells some sort of story. I’ve (really truly) received projects like this: (a ChatGPT-generated plot of completely made up data from gapminder) At a very quick glance, that looks like a plausible image. But holy crap it falls apart fast, both comically and tragically. Comically because, like, look at the y-axis in the scatterplot; or the x-axis ticks in the population grown chart that are sometimes spaced every 20 years, sometimes every 10 years, and has 1980 there twice; or the weird blobs in the map. Tragically—and most importantly—literally nothing in this image is real and none of the annotations make sense and none of the colors make sense and everything here is completely meaningless and devoid of any information. It’s pure philosophical bullshit—an image “produced without concern for its truth.” That’s what I mean when I say that it’s a forgetful and unreliable resource. Lots of that code is helpful as an illustration of what’s going on. Lots of the explanation is good and fine. But it subtly changed its mind halfway through and didn’t realize it (because it can’t realize it! it’s just a chain of statistically likely text!) Hopefully you can see where this is dangerous for learning. It can often “teach” you wrong, and you can only recognize that if you know stuff already. It’s extra dangerous if you then take that example output, paste it into your exercise, and submit it. I’m not even concerned about the plagiarism aspect of that—code is code and there are only a few ways to write {dplyr} code that will do this, and it’s easy to adapt from real human-based examples online, so I’m less worried about stealing other people’s work here. I’m concerned that it’s not real data. It made up values of 1, 2, 3, and 4 for some countries to illustrate grouping and summarizing. That’s good and normal. None of that is real. Don’t treat it as real.
November 2, 2025 at 10:17 PM
csthiago.bsky.social
www.nature.com/articles/d41...
This ultra-competitive scenario makes me very anxious.
1) almost a lottery
2) It is possible that the lottery would be more fair, as at least it wouldn't have the conscious/unconscious bias (mainly the "weights" the institution of origin carries)
Is academic research becoming too competitive? Nature examines the data
Applications for European research grants increased in 2025. Scientists say they’re feeling the competition.
www.nature.com
October 20, 2025 at 12:39 PM
csthiago.bsky.social
@grahamkendall.bsky.social you could check the pattern of self citations of this group : journals.plos.org/plosone/arti...
Every paper of them in this topic cite almost all of the previous ones. Rarely citing other groups
Evaluating the cost-effectiveness of COVID-19 mRNA primary-series vaccination in Qatar: An integrated epidemiological and economic analysis
Qatar implemented a mass primary-series vaccination campaign to mitigate the impact of the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to retrospectively evaluate the cost-effective...
journals.plos.org
October 19, 2025 at 4:51 PM
Reposted by Thiago
natcomms.nature.com
A study of ~7 million Brazilian births shows that infection with #chikungunya, #dengue or #Zika viruses during pregnancy is associated with increased risk of adverse perinatal outcomes

@csthiago.bsky.social

#viruses #epidemiology #pregnancy
Perinatal outcomes of symptomatic chikungunya, dengue and Zika infection during pregnancy in Brazil: a registry-based cohort study - Nature Communications
In this study of ~7 million Brazilian births, the authors show that chikungunya, dengue, or Zika infection during pregnancy is associated with an increased risk of adverse perinatal outcomes, with the magnitude of these effects varying by trimester of exposure.
bit.ly
October 15, 2025 at 6:15 PM
csthiago.bsky.social
Help!
Where can I find resources about causal mediation of ordinal outcomes? (using SEM)

Thanks 😄
#rstats @dingdingpeng.the100.ci
September 29, 2025 at 2:27 PM
Reposted by Thiago
fllaha.bsky.social
I’ve had the same impression while looking at academic epidemiology postdoc offers. So much focus on AI, machine learning, LLM experience. Are these the core skills we need now? What about subject matter knowledge, study design, bias, statistics, population health knowledge? Outdated?
epilorenzofabbri.com Lorenzo Fabbri @epilorenzofabbri.com · Sep 19
Looking at job offers (both academia and industry) and it’s basically all “AI” & Co. 😔
And WTF is “experience with LLM” for an academic post in epidemiology??
September 20, 2025 at 5:01 PM
csthiago.bsky.social
Sleuths,
Can someone explain to me how these CIs are possible?
www.nejm.org/doi/full/10....
It is not clear how they got RR from the Cox PH, as it would require choosing a time point (looks like an interpretation of HR as RR)

@lonnibesancon.bsky.social @sophieehill.bsky.social @retractionwatch.com
September 18, 2025 at 10:06 AM
csthiago.bsky.social
1/2
Does anyone know how to proceed for multiple imputations if one of the variables (fully observed) in the model has more than 5000 levels (in the outcome model, it is a mixed effect)?

#rstats #episky
September 5, 2025 at 7:10 AM
csthiago.bsky.social
Check out our last paper about the adverse consequences of arbovirus infection during pregnancy:
www.nature.com/articles/s41...

We have use the exact same approach for dengue, zika and chikunugnya. (including a negative control exposure!)
#dengue, #zika, #chikungunya, #epidemiology
Perinatal outcomes of symptomatic chikungunya, dengue and Zika infection during pregnancy in Brazil: a registry-based cohort study - Nature Communications
In this study of ~7 million Brazilian births, the authors show that chikungunya, dengue, or Zika infection during pregnancy is associated with an increased risk of adverse perinatal outcomes, with the...
www.nature.com
August 8, 2025 at 5:06 PM
Reposted by Thiago
bichinhos.bsky.social
Simplesmente um Husky Cerberiano
Foto de um carro parado com três cabeças de huskys siberianos saindo pela mesma janela parecendo ser um cerberus, um cachorro de três cabeças
May 4, 2025 at 10:19 PM