By "Care Lines", do you mean the personal alarm you wear around your neck or wrist? If so then here's my experience of them.
My Dad was diagnosed with dementia just after Mum died just over two years ago. He was okay for a few months, and then had a series of falls. As he was on his own, we got him an alarm for his wrist. I stayed with him for a few nights, and was woken by a woman's voice asking Dad if he was okay, or did he need help. Dad was still in bed and perfectly safe, he had just pushed the button by accident, and being a bit deaf, didn't respond to the poor woman. I had to speak for him. It was strange, talking to a box on the floor in the middle of the night.
If you don't have dementia, and don't have hearing loss, it is a very good system. They come out pretty quickly, and are thorough when checking for injuries before moving you.
Very good IMO.