We had a little old lady patient where we found out family was swiping her Percocet (ultra-strong pain pills) and replacing them with regular Tylenol. We were furious - a bit at the offense against our trust, but moreso at the thought of her suffering in pain so they could get high....
....but then she came in for an appointment, and appeared her usual pleasant self, in no particular pain. We asked if she'd been doing ok, and she cheerfully replied just fine; we asked if she had very many days of pain in the last month, and she cheerfully replied not really - "Those pain pills do just fine, but if I don't take two a day, I'm so stiff and achy in the morning..."
We realized the family had been stealing her Percocet
all along - she'd never been on them at all! While we were relieved she hadn't been suffering, we were all the more annoyed at her grandkids.
(So if you have an older relative who the doctor insists on 'drug testing', that's why - the doctor wants to try to be sure the patient is the one taking the potent pills...)
Hope your Grandma wasn't in undue pain because of this, at least.
You might want to check for other things they might have stolen from her (including social security numbers, bank information, etc.) - people who are dishonest about one thing are likely to be dishonest about other things...
