With these types of scams becoming increasingly common, I recommend everyone set up a code word with your family and don't tell anyone what it is. Practice it often. If you get one of these scam calls, ask for the code word to verify that it really is your family member.
My wife and I will do a call back if we need to talk about anything sensitive over the phone. I can call her, say that I'll need an account number or whatever the situation calls for, then we hang up and she calls me back so we can both be sure we are talking to each other. If I don't know what she's talking about during the return call then it's a scammer.
This is rare, but it gives protection against this type of scam.
Me thinks that one call from an old lady may have been just this, and when I chuckled a bit as I couldn't identify her voice she called me demented and hung up. Feel like the call was probing for the vulnerable.