Well according to the book it wasn't about seeing the same thing exactly so much as not having enough time to interact---basically they have a checklist and that doesn't format well with a human being---some people make it harder to check off boxes on that list---the specifics were drug users, mentally ill and certain races(apparently some races/cultures will rate even minor pain a 10 on the pain scale due to language usage in their native country)----if someone isn't sure what's real or not the boxes start getting complicated for example while I was in the hospital I had to fill out a form for an MRI---several days later pdoc asked why I hadn't had an MRI---I had no idea---well the form asked if you were pregnant check one box apparently I had just crossed it out and put maybe---I had a pretty intense hallucination/delusion of being raped and threw away my second plan B so I had no idea if I as pregnant or not. So yeah maybe it is variable but there is still a bias against the mentally ill because we aren't seen as cooperative when it comes to filling standardized forms.