Identifying patients transferred from another healthcare facility

[Bright381]

Hi,

I'm working on identifying patients who were transferred from another hospital or healthcare facility, as I want to focus specifically on those who began their care in the Emergency Department (ED).

Initially, I assumed this information would be captured in the admission_location column of the hosp.admissions table. However, this field appears to be unreliable. For instance, in the ed.triage table, some patients (with admission_location suggesting they were not transferred) have "transfer" listed in their chiefcomplaint, and discharge summaries confirm that at least some of these patients were indeed transferred from another facility.

Do you have any suggestions or recommended methods for reliably identifying transferred patients in MIMIC-IV—ideally without having to manually review each discharge note?

Thanks!