I bumped into some of our security guys on the range the other day...one of them led me to believe their qualification course is fairly easy yet more rigorous than the Illinois CCP qualification. They're good guys, and have helped me handle rowdy patients before. Mostly they are called for that sort of thing...a rowdy patient or family member who needs to either be strapped down or shown the door. They carry sidearms, tasers, batons, handcuffs and wear armor. They seem professional and they're good at handling their usual "customers" which generally includes combative patients, asshole families/visitors and just in general violent jerks.
We haven't had a shooting in some time but my hospital tends to realize that those without swords can still die on them, so they don't raise a fuss about armed security.
As for whether I'd trust them for an active shooter situation, well I'd trust myself more having heard one tell me that he doesn't see the need to practice outside of qualifications and that he really just puts in practice if he failed qualifications and gets to retry. I think they are required to qualify twice yearly, but I got the impression that for him it was more an inconvenience that he had to put up for a job. So while I don't doubt he'd exchange shots with an active shooter, I'd still like to be allowed CCW in the hospital, but that'll never happen.
For that other stuff, combative patients etc...yeah I love to have those guys and gals around.
I don't think our security officers are contractors, as they are hired and employed by the medical group that my hospital is a part of. They are offered benefits, but definitely not paid the same as police officers, so I suspect it is cheaper to hire them than police officers. Being a level 1 trauma hospital in the south side, the police are in our ED fairly regularly, so getting ahold of a cop isn't super difficult..there's usually pretty good odds that one will be there. Especially with the fairly stunning amount of shootings in the city lately..even by Chicago standards.