I think that makes sense, Thumper, but the people that I am thinking of didn't do this.

I used to set up work placements for people returning to work. People with severe diabetes tended to do this opposite of what you are suggesting and with held the information. First I knew of it was when I got an employer phoning me to say they had collapsed.

It obviously caused some problems, but on the personal side, it just goes to show that there must be some kind of stigma attached or people wouldn't risk their health.