Wait. What did I just read?!

I was doing some sleuthing trying to understand why the total NYC stats are so MASSIVE and I discovered:

**NYC is ESTIMATING #COVID19 hospitalizations NOT ON TESTS but on symptoms that match known cases***

First, hats off. NY has been hit hard:
1/

35% positive rate
50K cases in NYC alone?!
1500 deaths! :(

A few days ago (every day feels like a week now) I sent out the following tweet asking about odd wording on the NYC PDFs which they used before they came out with their data website:
https://www1.nyc.gov/site/doh/covid/covid-19-data.page

2/

The NYC COVID19 data page came out and I had to ask again... what does this "Every Hospitalized Cases" mean?

This is important because NYC cases are OFF THE CHARTS!
They provide a GitHub data repository (which is how I built last night's posts on date discrepancies).

3/

They have a pretty good data team over there because all of their README docs at GitHub are there, it's nicely organized... including this this snippet (screenshot and link):
https://github.com/nychealth/coronavirus-data/blob/master/README.md
4/

"intense resource and time constraints on hospital reporting systems"

No doubt! We've talked about the dangers of a society demanding real-time pandemic medical data in an election-night style format.

But what's that NEXT PART about?

5/

"...we have estimated the number of individuals diagnosed with COVID-19 who have ever been hospitalized by matching the list of key fields from known cases that are reported by laboratories."

Now, word of caution - maybe this estimation is totally normal but essentially...

6/

NYC is estimating hospitalizations and cases by ASSUMING that OTHER patients who visited ERs with SIMILAR symptoms in a database should AUTOMATICALLY be counted as #COVID19 patients

Stop me if I'm wrong but that could be ONE of the factors as to WHY NYC has SUCH a big caseload?

Now look - this may be SOP for a crisis like this... and I love a good regression formula... but

1) WAS it a regression formula? Or just a vlookup? Or worse yet... a filter?
2) How far back did they go? What period of time does "Ever Hospitalized Cases" cover?

Lot of questions