Data definition layer
Observation
Data dictionaries and data sets define what the system is capable of representing.
Pattern
Variation in data definitions across organizations leads to inconsistent implementation and behavior of clinical decision support (CDS) rules.
Insight
If a concept is not defined at the data dictionary level, it cannot be reliably captured, interpreted, or acted upon downstream.
Application
Data dictionary design must be treated as an architectural function within the data-to-outcome intelligence pipeline, as it directly constrains CDS logic, analytics, and clinical decision-making.
🔄 What This Means in Practice
• CDS inconsistencies may originate from data definition differences, not just logic errors
• Standard terminologies (SNOMED, RxNorm, LOINC) attempt to stabilize meaning—but rely on defined data structures
• Product and informatics teams should evaluate data definitions before building rules or alerts
• “Garbage in, garbage out” is incomplete — the issue may be what was never defined at all
ACS Perspective
From an Analyst Cognitive Stewardship™ perspective, system architecture directly shapes human reasoning.
If a system cannot represent a concept accurately, the analyst or clinician cannot reason about it accurately.
Data definition is therefore not just a technical layer—it is a cognitive constraint layer.
