As time goes on, I become more skeptical of any information that I do not collect myself.
People I do not trust:
The ER physician
The outpatient record
The outside hospital
I trust no one. Too often patients are "billed" as having a certain diagnosis, but the true diagnosis is quite difference. All the people I listed are honorable and doing their best. But patients change over time. The attending physician ALWAYS gets a more accurate history the next day. The physical exam changes and becomes more clear.
The worst thing I can do is to accept everything at face value.
This is nothing more than healthy skepticism but it takes time. A lot of time. Maybe even a diagnostic time-out for all but the most straightforward patient.
This is a key element of patient safety. Unfortunately it is all but ignored by the leadership of hospital medicine, where patient safety is addressed primarily at the system level. Reducing diagnostic error is all about the individual patient.
But, in a way, diagnostic error is a system problem because of the element of time. The major performance incentives for hospitalists today---rapid ER throughput, shorter lengths of stay, early discharge time and the generation of RVUs---run counter to the objective of spending more time on the individual patient.