Data intelligence · automation · analyticsA Praxis Global Institute platform
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

AAXBDMAT
Evidence developinglow confidence

Laboratory

Impermeable Mattress 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
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
DMQMILIZ
Compatible with harmonizationmoderate confidence

Demographics

{Have you/Has SP} ever served on active duty in the U.S. Armed Forces, military Reserves, or National Guard? (Active duty does not include training for the Reserves or National Guard, but does include activation, for service in the U.S. or in a foreign country, in support of military or humanitarian operations.)

Source releases
5
Available cycles
2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2021-2023
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

Relevant boundaries: 2011-2012 → 2013-2014 · 2013-2014 → 2015-2016 · 2015-2016 → 2017-2018 · 2017-2018 → 2021-2023

Praxis harmonization actions
  • Verify merge grain, companion variables, and component-specific analytic guidance for the new file context.
Supporting CDC/NCHS evidence
Remove from studyVariable historyCDC source
HRQ010
Evidence developinglow confidence

Laboratory

Has your hair been given a permanent or been treated with a hair dye or a hair straightener within the last month?

Source releases
1
Available cycles
1999-2000
Dataset
Mercury - Hair

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