The phrase "as to the severity" is correct and usable in written English.
It can be used when discussing or questioning the level or intensity of something, often in a formal context.
Example: "The committee is still deliberating as to the severity of the penalties that should be imposed."
Alternatives: "regarding the severity" or "concerning the severity".
Each side produced medical experts who contradicted each other's testimony as to the severity and origins of Routh's unstable behaviour.
He is expected to undergo evaluations early this week, with no indication as to the severity of his injury.
Since it arrived, opinions as to the severity of its consequences, its effects on different nations and the prescriptions to remedy them have varied wildly.
Despite being well informed as to the severity of the storm, the White House did not dispatch federal troops to the city until four days after the hurricane had hit, after well over a thousand had died.
"When he gets done making his analysis," he said, "we will have a pretty good idea as to the severity of the problem, how long it will take to fix and some parameters of where we have to go".
There was no immediate word as to the severity or nature of the injury.
Moreover, systemic administration of exosomes derived from IL-10-treated DCs is able to suppress the onset of murine collagen-induced arthritis (CIA) as well as to reduce the severity of established arthritis.
Eligible patients had at least one coronary artery lesion and no restrictions as to the number, severity and location of stenosis.
Although considerable differences of opinion continue to exist as to the timing, severity, and differential effect of the actual climate change associated with global warming, there seems to be consensus on three important aspects.
Current theory and evidence point to disruptions in self-concept and difficulties with emotion regulation as contributing to the severity of binge eating.
Additionally, we found that the time elapsed between trauma and definitive surgery had a significant correlation with time to return to work, although this parameter may be interpreted as linked to the severity of injury.
