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Praxis Data Lab

Praxis Data Lab · Study Builder

Build your NHANES study with harmonization intelligence.

Combine variables from the indexed Continuous NHANES catalog, choose the cycles you need, and see how Praxis connects source history, methods, cycle boundaries, and cross-code lineage into a study-specific harmonization view.

3variables selected
Praxis harmonization guidance available

Praxis found harmonization conditions for this study and has surfaced them below with the supporting source evidence.

3 variable assessments

AAXBDPLW
Evidence developinglow confidence

Laboratory

Impermeable Pillow Cover

Source releases
1
Available cycles
2005-2006
Dataset
Allergens - Household Dust

No normalized longitudinal change evidence is available for this variable. Absence of events must not be interpreted as proof of cross-cycle equivalence.

Evidence provenance: Praxis automated inference from indexed CDC/NCHS evidence

Remove from studyVariable historyCDC source
DMDMARTL
Compatible with harmonizationmoderate confidence

Demographics

Marital Status

Source releases
10
Available cycles
1999-2000 · 2001-2002 · 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018
Dataset
Demographic Variables & Sample Weights

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

Evidence signals: source-derived · automated-difference

Relevant boundaries: 1999-2000 → 2001-2002 · 2001-2002 → 2003-2004 · 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

Praxis harmonization actions
  • Verify merge grain, companion variables, and component-specific analytic guidance for the new file context.
  • 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.
  • Apply cycle-specific eligibility rules and restrict the pooled analytic population to a defensible common target population.
  • Confirm that the construct and coding are unchanged before pooling or recoding.
Supporting CDC/NCHS evidence
Remove from studyVariable historyCDC source
RIDRETH3
Compatiblehigh confidence

Demographics

Recode of reported race and Hispanic origin information, with Non-Hispanic Asian Category

Source releases
18
Available cycles
2011-2012 · 2011-2012 · 2011-2012 · 2011-2012 · 2011-2012 · 2013-2014 · 2013-2014 · 2013-2014 · 2013-2014 · 2013-2014 · 2015-2016 · 2015-2016 · 2015-2016 · 2015-2016 · 2015-2016 · 2017-2018 · 2017-2020 · 2021-2023
Dataset
Demographic Variables & Sample Weights

RIDRETH3 was introduced in 2011-2012 as an expanded race/Hispanic-origin recode that distinguishes Non-Hispanic Asian participants following the revised NHANES sampling design. It is a stable construct within its released era, but it is not simply a renamed RIDRETH1.

Evidence provenance: CDC/NCHS source-confirmed evidence · Praxis deterministic adjudication

Evidence signals: source-stated

Praxis harmonization actions
  • Pool RIDRETH3 within 2011-2012 and later calibrated cycles when the expanded categories are analytically appropriate. Treat RIDRETH1 and RIDRETH3 as parallel construct variants; use an explicit common recode when combining analyses across their differing category schemes.
Supporting CDC/NCHS evidence
Remove from studyVariable historyCDC source