It is like anything else, the more severe a persons condition, the more precautions you need/or should take.
So, if 24 hr. monitoring, makes you feel comfortable, you can get it, if personal contact support makes your boat float, you can get it too, or if you prefer a simple medallion or bracelet, you can get that as well. If you do use a medallion, or bracelet, just get one that clearly displays it's intent, and is engraved on the back side with the most critical information regarding your condition.
There is also an app for your phone, that has all your doctors listed, their contact info, all your meds, your personal emergency contacts, etc
You can even print it out for your doctors office.