Detailed Explanation
Source documents constitute the original records where clinical trial data are first recorded, serving as the foundational evidence that supports all data entered into case report forms and included in regulatory submissions. These documents provide the verifiable trail of evidence that enables regulatory authorities, auditors, and monitors to confirm that the data underlying efficacy and safety conclusions accurately represent what was observed during the trial. The integrity of clinical trial data ultimately depends on the quality, completeness, and accessibility of source documents.