Yes I have. I had 2. The first one of course said I hung was wrong but the bone weary exhaustion I was experiencing told me for sure something was wrong. I was falling asleep in my car at stoplights. People were beeping at me. Kinda funny when I picture it in my head now. The second sleep study showed I never go into R.E.M. sleep. That's the deep sleep. It showed I woke up 27 times an hour even though I wasn't aware of it. So I got a cpap machine and that has made a world of difference! I also have a hypoactive thyroid which makes you tired too.