Dan Ly

When the podcast described “three-cueing,” I got angry at its ridiculousness, and I never get angry

The podcast is how I found out about it.

Statistician Life-saving breakthroughs, innovative therapies, and next-generation technologies. Through vision, tenacity, and inspiration, UCLA Health’s world-class researchers are redefining human health and...

Hi! I'm looking to hire a full-time programmer/data analyst with SQL experience to work with EHR data! Details here: uclahealth.avature.net/careers/JobD...

You see it often because it’s a standard error

Leniency Designs: An Operator's Manual We develop a step-by-step guide to leniency (a.k.a. judge or examiner instrument) designs, drawing on recent econometric literatures. The unbiased jackknife instrumental variables estimator (UJIVE) is...

Excited to post a new working paper with @instrumenthull.bsky.social and Michal Kolesár: arxiv.org/abs/2511.03572

Will post a thread on it soon, but if you're interested in judge/examiner designs, I think you'll find this guide very helpful!

Kid a few years from now: “Daddy, why is my name Yoshinobu?”

Someone on a listserv I was on asked how to install SPSS on a server. I scoffed before realizing one day soon I'll be asking how to install Stata on a server and someone else will be rolling their eyes...

Congrats!!!

A great listen!!!

Question Has hospital length of stay increased more for Medicare Advantage beneficiaries than for traditional Medicare beneficiaries since the COVID-19 pandemic?Findings In this cohort study involving more than 89 million hospitalizations from 2017 to the third quarter of 2023, Medicare Advantage beneficiaries experienced disproportionately greater increases in extended hospital stays, especially among those discharged to skilled nursing facilities.Meaning These findings suggest that the Medicare Advantage plan design and practices may contribute to hospital discharge delays, with implications for patient outcomes and hospital capacity as enrollment continues to rise.

New paper w/ Brian McGarry, Ashvin Gandhi, and Drew Wilcock in @jamainternalmed.com!

Hospitals are complaining across the US that patients are "stuck" waiting for rehab beds at nursing homes when they are medically stable and ready for discharge. What is going on??

jamanetwork.com/journals/jam...

Woo Laura!!!

Will the panel include fixed effects?

So sorry! It’s so much work! Best of luck with whichever direction you take!

To be clear, we use the ED because it’s a clean sample largely free of prior influences from prior docs. This phenomenon of variation across docs in same facility can likely be found in length of stay for hospitalists, pneumonia read rates for radiologists, etc.

We agree that SDoH are important. This is why we take care to make comparisons within ED while also controlling for such things as time of arrival, ESI, and location within ED. We suspect there aren’t large differences in SDoH across docs in same ED after controlling for time, location, ESI, etc.

We use mortality because it’s an important measure and it’s largely non-contestable how to measure it. How would one measure an indicated vs not indicated admission? We also find that admitted patients of higher admitting docs more likely to be discharged before 24 hrs.

Thanks. Having more docs not trained in EM at the VA is something we acknowledge in the limitations of our paper, as is our inability to include doc characteristics such as training. But other lit using Medicare data show similar level of admit variation. www.healthaffairs.org/doi/pdf/10.1...

We didn’t get that granular but that’s a great question to explore.

Whoops, tagging Stephen’s bluesky account, not his Twitter account. @coussens.bsky.social

Variation in Emergency Department Physician Admitting Practices and Subsequent Mortality This cross-sectional study using Veterans Affairs data from more than 2 million patient emergency department visits over 8 years examines the variation in physicians’ admission propensities and how th...

But higher admission rates do NOT ⬇️ important adverse outcomes like mortality. Given high costs of admission ($, provider & facility capacity, pt well-being), better understanding how such variation arises could be fruitful for pts, docs, and healthcare system. 8/ jamanetwork.com/journals/jam...

In sum, there is much variation in admit practices, likely due to diffs in skill & risk aversion. This mirrors variation in other doc specialties, who also greatly differ in their decisions. Of note, results do NOT argue for high-admit docs to indiscriminately ⬇️ admit rates. 7/

But seeing a higher-admitting doc does NOT reduce your likelihood of dying (either within 30 days [shown here], 7 days, 14 days, 90 days, or a year). 6/

Higher-admitting docs also order more radiology and laboratory tests in the ED. This suggests that admission rates may also be reflective of practice pattern intensity more generally. 5/

With data on over 2 million pts across 100 hospitals nationwide, we find that patients treated by docs with higher admission propensities are more likely to be discharged from the hospital within 24 hours when admitted, suggesting a lower clinical need for their hospitalization. 4/

We use rich VA EHR data with info not available in claims data such as ⌚️ of arrival, location within ED, and ESI (a # based on pt severity). This allows us to demonstrate that variation in docs’ admission rates is attributable to docs themselves, not to diffs in pt health. 3/

The decision to admit or discharge a patient is one of the most important decisions an ED doc makes. By how much do ED docs vary in this decision? A lot! Being treated by a doc in top 10% vs bottom 10% can nearly double your probability of admission. 2/

🚨New paper🚨The emergency department (ED) is like a box of chocolates; you never know which doc you're gonna get. What happens when you get a doc that admits patients more often? Are you less likely to die? @stephencoussens and I explore this question in @JAMAInternalMed.🧵1/

Wow, amazing news. Congrats to you both!

I’m really sorry to hear about that.

I do think a fair bit of thought goes into these recs, and hope is that there are active discussions between primary care doc and the patient about risks and benefits to screening over age 75. It’s not explicitly discouraged, although I’m not sure what insurance coverage is for colos for those >75