Time inconsistencies in ed.edstays, ed.pyxis and hosp.prescriptions

[Bright381]

I found some inconsistencies between the ED intime and pyxis charttime and prescription starttime. For some patients that went through ED, the charttime and starttime (from ed.pyxis and hosp.prescriptions respectively) are anterior to their registered intime in the Emergency Department (ed.edstays.intime).

I would like to get precise timings but I don't know which ones are more likely to be accurate or which ones are manually registered vs automatically registered.

Can you tell me how are registered these times ? Are there other (not too complicated) ways to determine which are trustworthy ?