I think the clinician’s assessment of the patient’s pain is more useful than the patient’s assessment of their own pain, as far as triage is concerned. The currently used pain scale is only helpful in assessing response to treatment (the trend). Mine is more realistic:
Scalpel’s Pain Assessment Scale
From my small experience in a hospital, I left with the strong impression that personal pain ratings are more often about what the patient wants than the level of pain the patient is experiencing. Everyone on my floor new the magic number: 7. If you’re a 7/10, you get morphine.