What exactly does "Hospital Grade" mean?

I plan on changing my outlets since it seems like a cheap enough tweak and most here on the forum agree that it makes a difference. But what actually IS the physical difference between hospital grade and non-hospital grade outlets?
>>"And I don't think that requiring "X" amount of force to remove a plug from an outlet makes the outlet superior for our purposes although a snug fit is obviously necessary."<<

It's Contact Pressure......You misssed the whole point.

Nerspellsner, LOL, I never heard of that test, LOL.
You do know there is a device that plugs into the outlet and while extracting it, will give you the resistance to the pulling action in ounces...
Jea48, I have heard of that device but I have never used it. I remember hearing that the device is connected to the ground pin only. It has to stay connected to a hospital grade outlet with 4 oz of pressure for a certain amount of time. I concur with your statement about removing a plug under a load from an outlet will cause an arc, regardless of the type of outlet.
All outlets get looser as stuff is plugged in and out many times. A "pull test" is a practical way for the maintenance staff to determine how far the degradation has gone, and when it is time to replace the outlet. Wearout should not be a concern for audio applications since it does not involve frequent plug/unplug cycles.
Jea48, can you please explain the benefit of "Contact Pressure"? I mean I know what it means, but are you saying that the better contact pressure of hospital grade outlets is desireable because of an enhanced electrical flow, or as some others seem to be suggesting, that the benefits are in the power chord not being pulled out too easily/accidentally???