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
Variable history and harmonization report.
Review variable definitions, cycle chronology, survey design, laboratory methods, method-change boundaries, detection limits, and evidence-backed harmonization actions.
1matching variable codes
10 release records across 10 datasets and 10 cycles.
Search scope
Results for “DR1IP182”
Scientific safeguard
Qualified assessment is authoritative; chronology remains supporting evidence.
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
Qualified harmonization assessment and indexed evidence
Each variable first shows the current qualified assessment used by Study Builder, followed by cycle-specific source evidence and method chronology.
DR1IP182Compatible with harmonization
PFA 18:2 (Octadecadienoic) (gm)
- Observed years
- 2003–2023
- Release records
- 10
- Datasets
- 10
- Components
- Dietary
Qualified Praxis harmonization assessment
Compatible with harmonization · moderate confidence
No blocking method discontinuity is identified inside the selected cycle span, but one or more longitudinal changes require explicit harmonization conditions before pooling.
Evidence provenance: Praxis automated inference from indexed CDC/NCHS evidence
Relevant boundaries: 2003-2004 → 2005-2006 · 2005-2006 → 2007-2008 · 2007-2008 → 2009-2010 · 2009-2010 → 2011-2012 · 2011-2012 → 2013-2014 · 2013-2014 → 2015-2016 · 2015-2016 → 2017-2018 · 2017-2018 → 2017-2020 · 2017-2020 → 2021-2023
Praxis harmonization actions
- Verify merge grain, companion variables, and component-specific analytic guidance for the new file context.
- Review the adjacent codebooks/methods. Keep this boundary as documentation variation unless source evidence confirms a substantive method or instrument change.
- Select the weight appropriate to each cycle and subsample; when pooling cycles, construct the combined weight according to NHANES guidance rather than reusing a single-cycle weight unchanged.
Variable names / labels over time
- PFA 18:2 (Octadecadienoic) (gm) — 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2017-2020 · 2021-2023
Cycle-by-cycle release history
- 2003-2004: DR1IFF_C — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2005-2006: DR1IFF_D — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2007-2008: DR1IFF_E — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2009-2010: DR1IFF_F — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2011-2012: DR1IFF_G — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2013-2014: DR1IFF_H — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2015-2016: DR1IFF_I — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2017-2018: DR1IFF_J — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2017-2020: P_DR1IFF — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)
- 2021-2023: DR1IFF_L — PFA 18:2 (Octadecadienoic) (gm) — Dietary Interview - Individual Foods, First Day (Dietary)