We did a major update of this material in 2016:
The Barbell Prescription | The Aasgaard Company
The obvious problem being that very few if any studies are ever conducted with older adults and correctly performed barbell exercise and/or programming.
We run into this problem every year in the Science Review at the Coaches Convention. There are plenty of studies done with older adults and "resistance training" but it's the same old, same old. Machine based exercises done for sets of 10-15. Most of which go on to showcase nothing more than The Novice Effect, which is that basically any sort of physical activity causes some modicum of strength improvement in an untrained population whether they are 25 or 75.
There is very little of value to extrapolate from these studies to further our cause other than to say that "resistance training is good" - which MOST everyone pretty much agrees on.
The actual life changing work taking place with seniors is all being done in private practice
I've used the quote "I have found a fountain of youth, and it flows out of a barbell" in so many conversations with young'n's and older folk who are looking for that final push to get into a gym.
I may have read this article fifty times.