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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.

4variables selected
Praxis harmonization guidance available

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

4 variable assessments

AAXRMDES
Evidence developinglow confidence

Laboratory

Room Description

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
ACD080
Compatible with harmonizationmoderate confidence

Questionnaire

In what country was {your/SP's} mother born?

Source releases
3
Available cycles
1999-2000 · 2001-2002 · 2003-2004
Dataset
Acculturation

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

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

Praxis harmonization actions
  • Apply cycle-specific eligibility rules and restrict the pooled analytic population to a defensible common target population.
  • Verify merge grain, companion variables, and component-specific analytic guidance for the new file context.
Supporting CDC/NCHS evidence
Remove from studyVariable historyCDC source
ARXO2WD
Evidence developinglow confidence

Examination

OCCIPUT-TO-WALL DISTANCE IN CENTIMETERS

Source releases
1
Available cycles
2009-2010
Dataset
Arthritis Body Measures

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
AUQ031
Compatible with harmonizationmoderate confidence

Examination

In the past 24 hours, have you been exposed to noise so loud that you would have had to raise your voice to speak to someone an arm's length away?

Source releases
2
Available cycles
2017-2018 · 2017-2020
Dataset
Audiometry

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: 2017-2018 → 2017-2020

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.
Supporting CDC/NCHS evidence
Remove from studyVariable historyCDC source