A mapping should not silently increase clinical certainty
WHO’s documentation guidance says concepts should reflect the granularity supported by current clinical knowledge, with symptom-level documentation retained when a disease is not confirmed. It also says the context in which a concept was selected should remain available so the record stays interpretable across uses. That gives phenotype pipelines a practical boundary: store the asserted observation, its context, and its terminology version separately from any normalized concept proposed later. Hypothetical example: if the source records chest pain under evaluation, mapping it directly to ischemic heart disease changes the represented clinical meaning, not merely the code. Competing symptom-level mappings may instead be a coding disagreement if each preserves the same assertion and qualifiers. Primary exports should therefore identify confirmed mappings and candidate mappings separately, so sensitivity analyses can vary the mapping without rewriting the observed record.