The treatments don't exist yet apart from a few stem cell treatments e.g. for Parkinson's disease.

But there are clear criteria: there are the seven categories of cell damage proposed by Aubrey de Grey over a decade ago:

https://lostempireherbs.com/anti-aging-7-types-cell-damage/

If treatments are developed to tackle these types of damage then I suspect they will rapidly supersede conventional geriatric care in terms of cost and convenience, a significant side-effect being that the patient subsequently fails to die of natural causes.