This is @brianwwhitcomb and @ashley_naimi with a short twitter takeover of @AmJEpi about our latest work in the AJE Classroom about ‘noncollapsibility’ #epitwitter Heard or read about ‘noncollapsibility’, but not sure what it is? Is including nonconfounding risk factors in regression models to estimate causal exposure effects a good or bad idea? Does it even matter?

👋 hi, @LucyStats here! Kicking off some live tweeting of this exciting discussion on the future of epidemiologic methods.

@nondogmatist kicks us off, asking the panelists to discuss what they see in the future of Epi Starting us off, @edwardsjk and @robertwplatt both talk about *data*

The difference between the “source cohort” or “dark data” and the data that we’re actually using - We often just see the tip of the iceberg 🏔, we need to develop and use methods that take this into account

Happy New Year! To celebrate 2020, how about an #EpiEllie #tweetorial?

Today, let’s talk about e-values and how to interpret them! E-values were first developed by Tyler Vanderweele and Peng Ding, and is a type of threshold-based quantitative bias analysis.

The original paper introducing the e-value is here: annals.org/aim/article-ab…

👋 @LucyStats here! Today we’re going to do a little stats primer on testing for non-linear terms when fitting a model. What do you do when trying to decide whether to include a non-linear term in a model?

1️⃣ test the nonlinear term, if significant leave it in
2️⃣ if you have enough dfs, include the nonlinear term regardless of significance
3️⃣ never include nonlinear terms
4️⃣ comment

Hello #epitwitter! Time for an @epiellie @AmJEpi tweetorial.

Today’s topic is the Target Trial Framework for #causalinference and how to apply it to improving observational studies.

#epiellie So, what is the #targettrial framework?

Well it’s not a new method! Instead think of it as pedagogical device that provides a structured way to build your research question and study design for observational studies and minimizes the potential for bias.

The Most Read article in @AmJEpi is a simple, but important, 2013 paper on gun ownership & suicide death in the US.

Critics argue you can’t make cause & effect conclusions based on ecological studies, but is that always true?

Let’s discuss! #epiellie

academic.oup.com/aje/article/17… So let’s start with some background. What is an ecological study?

It may sound like it’s about the environment, but that’s not really true.

In epidemiology, an ecological study is one where all data about groups not individuals.

It’s time for some #cartoonepi & #epiquiz fun!

Today, let’s talk about Difference-in-Difference analyses and how to use them to estimate the impact of policy changes!

Our example paper is from our May issue by @DrRitaHamad & colleagues.

#epiellie I love this paper by @DrRitaHamad which tries to answer the question: did updating the allowed contents of the WIC package to include healthier options actually impact diet & nutrition during pregnancy?

Link👇🏼academic.oup.com/aje/article-ab…

Happy Tuesday, #epitwitter! There’s been a lot of discussion #onhere about #causalinference lately, but that’s not all that epi is about.

For this week’s #epichat with @epiellie, let’s talk about descriptive epi!

#epiellie To kick things off, an #epiquiz:

How often do you do descriptive epidemiology in your work or research?

(click to see poll options)