Should investigators record the relationship of a Serious Adverse Event to the study drug in source documents? Or is it sufficient if the other facts of the event are recorded (Event description, severity, start and stop dates) and then for the investigator to document their medical judgement regarding the relationship on the SAE form or CRF itself?

I ask this question because I have encountered reluctance from some investigators to record this in the patient's medical records as they consider it to be a subjective rather than a factual statement. There is also the implication that there might be some impact on medical insurance where this is effective.

I would be interested to hear the opinions and experience of others on this issue. Thank you.