Harmonization summary
1 label-stable codes
- Label changes detected
- 0
- Multiple dataset contexts
- 0
- Unique codes
- 1
- Enriched codes in this report
- 0
Praxis Data Lab · Variable History
Review variable definitions, cycle chronology, survey design, laboratory methods, method-change boundaries, detection limits, and evidence-backed harmonization actions.
12 release records across 12 datasets and 12 cycles.
Search scope
Harmonization summary
Scientific safeguard
Praxis separates source-stated method or instrument changes from automated differences in CDC/NCHS method text. The qualified harmonization assessment below is the researcher-facing conclusion; method chronology explains the underlying evidence and does not override that adjudication.
Variable-by-variable chronology
Each variable first shows the current qualified assessment used by Study Builder, followed by cycle-specific source evidence and method chronology.
Compatible · high confidence
CDC/NCHS documentation supports continuity of the core NHANES anthropometry methods across Continuous NHANES, including waist circumference. Indexed differences for this variable are limited to dataset context and documentation wording, not a confirmed waist-measurement discontinuity.
Evidence provenance: CDC/NCHS source-confirmed evidence · Praxis deterministic adjudication