Not Clinically Significant (NCS) is a term used to indicate that a findingósuch as a lab value, vital sign change, or clinical observationódoes not have meaningful medical impact based on predefined criteria.
In clinical trials, NCS determinations are typically guided by protocol definitions, clinical judgment, and thresholds set in statistical or medical monitoring plans. Consistent use of NCS classifications helps standardize safety narratives and supports clear interpretation of results. Even when findings are labeled NCS, documentation should remain complete and traceable to support monitoring and audit expectations. Proper classification supports accurate safety assessment and avoids under- or over-reporting clinically meaningful changes.