Critically important in some circumstances. I spent 3 hours yesterday obtaining conclusive evidence that a patient had a specific type of valve replacement surgery, because their treatment (years after the surgery for a totally unrelated issue) depended on this and various providers had documented conflicting data previously.

It turned my 15 hour workday into an 18 hour workday, but I could not have slept without knowing the answer to this question because of the degree of impact it had on this patient.