Aaron Schwartz
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aschwartz.bsky.social
Aaron Schwartz
@aschwartz.bsky.social
MD-PhD professing at the University of Pennsylvania. Health, economics, and health economics.
"Beta blockers after heart attack"- maybe the best known quality measure. It was often used in health services research. It was such a successful measure, it was retired by NCQA because hospitals were performing so well. There was a memorable mock eulogy in NEJM at the time. But.. (1/2)
November 13, 2025 at 3:57 AM
It’s golden season for the ginkgo trees and I am here for it. A reminder that Philadelphia is home to the oldest ginkgo tree on the continent. 240 years and counting.
November 6, 2025 at 11:20 PM
Very large premium increases on the horizon. www.inquirer.com/health/penni...
October 16, 2025 at 2:34 PM
The mail and email we get for my father in-law, who has been dead for over a year, is really a thing to behold.

From his former health insurer and from his former landlord:
October 10, 2025 at 5:01 PM
With Hepatitis B vaccination under threat, here is one frustrating fact about testing for Hep B. It’s super complicated, based on multiple tests. I’ve often consulted this chart to interpret tests, and occasionally ended up in the dreaded “four interpretations possible” section.
September 18, 2025 at 8:03 PM
Here is the email from President Jameson.
July 1, 2025 at 8:43 PM
Masterclass at #ashecon2025. New research on how Medicare Advantage affects total Medicare spending.
June 25, 2025 at 2:16 PM
Next time you see one of these white towers, you will know what they are: VORs. Not castles, but temples to human ingenuity! They are still in use as backups to GPS.

You can read more about them in this neat 1960 article in Electronics World (9/9).

www.rfcafe.com/references/e...
June 15, 2025 at 12:59 PM
If the signals are received at the same time (in phase), the plane is due north of the station. Due south of the station, the signal pulses have the maximum time between them (out of phase). (Detail: a second reference signal resolves ambiguities between, say 90 degrees and 270 degrees) (7/n)
June 15, 2025 at 12:59 PM
The ingenious solution: The station sends two signal pulses, about 30 times each second. The first signal is sent in all directions. The second signal is sent from a transmitter spinning 30 times each second. The time difference between the signals tells planes the direction of the station. (7/n)
June 15, 2025 at 12:59 PM
It turns out our ears detect miniscule differences between our left and right ears in the timing of sound arrival and the volume of sound. Cool, huh? But, this only works because sound is relatively slow (~700 miles per hour), and sound intensity falls rapidly over distance. (4/n)
June 15, 2025 at 12:59 PM
On Friday I was driving with my 6-year old daughter near a regional airport. She points out the window at a big white structure and shouts, "Look: a castle!"

What is it? Not a castle. More like a temple to human ingenuity! A thread... (1/n)
June 15, 2025 at 12:59 PM
As you would expect, the effects were largest for those with more prescriptions at baseline. (10/11)
May 14, 2025 at 9:32 PM
But, once the early Medicaid loss group began losing LIS, these folks started filling fewer prescriptions than those who still had LIS. Around this time, mortality rates diverged for these two groups. After both groups lost LIS, prescription fills converged; so did death rates. (9/11)
May 14, 2025 at 9:32 PM
So Eric led a study to find what happens to duals who lose Medicaid earlier in the year (who lose more LIS) versus the duals who lose Medicaid later in the year. These groups looked remarkably similar at baseline. (8/11)
May 14, 2025 at 9:32 PM
...if a dual loses Medicaid coverage, they can lose the LIS. Here’s the strange part. A dual who loses Medicaid in June will lose the LIS at the end of that year (6 months). A dual who loses Medicaid in July will lose the LIS at the end of NEXT year (17 months). 🚨 This is a natural experiment. 7/11
May 14, 2025 at 9:32 PM
May 4, 2025 at 11:52 AM
It looks like the antisemitism demand letter, sent on the eve of Passover, was drafted by the wicked lawyer, the simple lawyer, and the one who doesn’t know how to ask.
April 19, 2025 at 9:03 PM
Incredible result. Plus, 1) these patients were already in their 70s when getting the vaccines and 2) this is zostavax, not even the most effective HZV vaccine available.
www.nature.com/articles/s41...
April 2, 2025 at 5:03 PM
March 29, 2025 at 2:12 AM
Penn takes more steps to reduce budgets with federal support in jeopardy.
March 10, 2025 at 2:26 PM
It’s my favorite.
March 9, 2025 at 2:51 AM
Thanks Fieldhouse & Mertens (2024) for help with my rally sign. #standupforscience2025
March 5, 2025 at 8:59 PM
February 27, 2025 at 6:50 PM
Like me, you too can be free from concern about egg prices. All it takes is some large upfront costs and daily efforts that are absolutely not cost-effective.
February 12, 2025 at 4:42 PM