eSource (electronic source data)

What does eSource (electronic source data) mean in clinical research?

FDA's guidance on electronic source data in clinical investigations, finalized in 2013, defines eSource as data initially recorded in electronic format. It can include information in original records and certified copies of original records of clinical findings, observations, or other activities captured before or during a clinical investigation and used to reconstruct and evaluate it.^⁠[1]

For recruitment, the eSource that matters most is usually the EHR. The documentation showing that a participant met each inclusion and exclusion criterion, such as a pathology report, a lab value or a medication history, lives there, and monitors will trace eligibility back to it during source data verification. If pre-screening relied on a note the monitor cannot find, the eligibility decision is hard to defend.

Practical note: record the source document behind each eligibility criterion at the time of pre-screening, so the coordinator, the investigator and the monitor all verify the same evidence. Identify shows the chart evidence for each criterion it evaluates, which shortens that check.