Interesting article - but I'm surprised they are confused at...

Interesting article - but I'm surprised they are confused at all, and didn't simply look up the difference between moderate and severe ARDS. They are both absolutely terrible conditions historically with very similar death rates. The definition is based on the amount of oxygen in the blood, or to be precise above (moderate) or below (severe) 100 mmHg PaO2/FIO2. If you measure at less than 300 mmHg, you have ARDS. It is better to have more oxygen in the blood than less. But if you are put on a ventilator, then you are in serious trouble. If one patient has 99 mmHg, and another has 101 mmHg, I doubt their chances of survival differ very much.

From the link below: The mortality of ARDS is commensurate to the severity of the disease, it is 27%, 32%, and 45% for mild, moderate, and severe disease, respectively. (This is from all causes, and uses data prior to Covid 19 - which has an 80 to 90% death rate from ARDS roughly).

https://www.ncbi.nlm.nih.gov/books/NBK436002/

Hopefully they update their article rather than not bothering to check basic facts. What they are reporting with the compiled list of announcements is great however IMO.