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Nov 13, 2022 15 tweets 15 min read Read on X
Biostatician @MikeLaValley8 @BU_BMC_Rheum presents a quick overview on how to appropriately interpret results from studies #ACR22

Of course this is not an exhaustive deep dive, but covers some common errors of interpretation Image
@MikeLaValley8 @BU_BMC_Rheum First, what is your research question? What is the question you are trying to answer with t he study?

👉Does this exposure CAUSE this outcome?

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum What are common observational study designs and what are big issues to watch out for?

These are issues that can affect the validity of their results.

There are more potential issues within these study designs that is beyond the scope of this table

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum We care about confounding in observational studies, because individuals are not randomized to each exposure of interest.

But first, what is a confounder?


#ACR22
@MikeLaValley8 @BU_BMC_Rheum Some basic DAGs (directed acyclic graphs) that illustrate exposures, outcomes, and confounders

When thinking about adjustment or other ways to deal with confounding, it can be useful to draw out the DAGs to show what you think the relationships between variables are

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum Example A: a common cause creates a non-causal association between the exposure and outcome

⭐Adjustment: tries to remove the effect of a common cause that could create an apparent relationship between exposure and outcome

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum Example B: Age confounds the relationship between CKD and mortality

Example C: Adjusting for age removes that confounding

Example D: If ethnicity is not measured well in a study, this leads to residual confounding even after adjustment

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum ⭐Restriction: Another way to try to handle confounding

It creates a homogenous group who are more likely to show the effect of the exposure or treatment

But caution! 🛑This can lead to regression to the mean

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum Example of regression to the mean with restriction using a BP threshold

🔎No restriction (full plot): BP is strongly correlated with time

🔎Restrict to high BP at baseline: there appears to be a reduction in mean DBP over time when there really is no change

#ACR22 ImageImage
@MikeLaValley8 @BU_BMC_Rheum A word on using p-values to estimate effect size: DON'T DO IT. That's not what this means at all.

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum What is effect size?

👉provides the measure of difference between groups or the magnitude of association between exposure and outcome
👉gives the clinical significance of the exposure for the outcome – is the observed effect large enough to be important?

#ACR22
@MikeLaValley8 @BU_BMC_Rheum A bit about confidence intervals

The confidence interval range can be evaluated to see:
🔹If values of clinical relevance lie in the range (clinical significance)
🔹If the null value lies in the range (statistical significance)

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum Finally, #Table2Fallacy

Table 2 is often used to show the adjusted results of the exposure

Variable types are highlighted in this Table 1:
🔹Exposure of interest in blue
🍎Outcomes in red
🍏Confounders (that were adjusted for) in green

#ACR22 Image
@MikeLaValley8 @BU_BMC_Rheum #Table2Fallacy

The effect estimates for the blue (exposure of interest) are interpretable ✅

The effect estimates for the red (confounders that were also adjusted for) may not be interpretable 🛑

#ACR22 ImageImage

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More from @rheum_cat

Nov 13, 2022
#ACR22 social media talk, very meta
Part 1️⃣: optimize your conference tweeting
If you're reading this you probably know all of this!

The first pro-tip was figure out the conference hashtag
The second? Engage with others in rheum
#ACR22
What else?

👉amplify your group
👉amplify speakers and sessions of interest
👉amplify your colleagues so they will amplify you in turn

#ACR22
Read 10 tweets
Nov 13, 2022
#ACR22 infection (COVID) posters Image
Abs 0784 @CCalabreseDO

Cleveland Clinic breakthrough infections, including data on n=21 who received Evusheld

📌Publication here: pubmed.ncbi.nlm.nih.gov/35791921/

#ACR22
@CCalabreseDO Abs 0779 @CCalabreseDO

Experience with evusheld PrEP with IMID on BCDT at Cleveland Clinic

📌Publication here: pubmed.ncbi.nlm.nih.gov/36123015/

#ACR22
Read 13 tweets
Nov 13, 2022
The EULAR e posters were tiny (bad) but speakers could zoom in and out (good)

That would have been nice for #IgniteTalks #ACR22
The sound is adequate though. EULAR issue was that the sound was poor in their (smaller) poster tour stages #ACR22 #IgniteTalk
Read 4 tweets
Nov 13, 2022
#ACR22 epidemiology posters Image
Abs 0700 @zach_wallace_md
💻Using NLP, ML algorithms to identify ANCA vasculitis cases

They also looked at the difference in performance metrics with/without filtering keywords

An explosion of NLP studies in rheum! #ACR22
@zach_wallace_md Abs 0732 Ho, et al. @JYazdanyMD @MilenaGianfran
💻Part of the explosion of NLP studies in rheum

Here the UCSF group aimed to capture VZV cases (differentiate from vaccination); and to capture active vs historical cases

See their diagrams explaining the steps!
#ACR22
Read 13 tweets
Nov 13, 2022
We have learned quite quickly that a virtual ONLY poster hall mixed into a hybrid meeting doesn't work well.

Poor wifi and the crashing platform compound the problem

And if it's online ONLY, is that truly hybrid?

#ACR22
This is not a complaint thread. I am hoping we can have discussion about what works/doesn't work, and what could be done next year for #ACR23
It goes without saying that an in-person poster hall is the most requested item on the wishlist for #ACR23

@GrantSchulert @Tuhina_Neogi
Read 5 tweets
Nov 13, 2022
Really enthused that some of the @rheum_covid #ILAR grant recipients could join us at this event tonight & talk about their work and their experiences
@panlarleague @aflarrheum

#ACR22
@rheum_covid @PanlarLeague @AFLARRheum Carolina Isnardi - Argentina
on behalf of the SAR-COVID registry

@gponsestel

#ACR22
@rheum_covid @PanlarLeague @AFLARRheum @gponsestel The setup of the SAR-COVID registry in Argentina

@rheum_covid #ACR22
Read 20 tweets

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