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

AAXFLTYP

Evidence developinglow confidence

Laboratory

Type of Floor Covering

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 study Variable history CDC source

ALQ151

Compatible with harmonizationmoderate confidence

Questionnaire

Was there ever a time or times in {your/SP's} life when {you/he/she} drank {DISPLAY NUMBER} or more drinks of any kind of alcoholic beverage almost every day?

Source releases: 6
Available cycles: 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2017-2020 · 2021-2023
Dataset: Alcohol Use

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: 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.
Confirm that the construct and coding are unchanged before pooling or recoding.

Supporting CDC/NCHS evidence

Remove from study Variable history CDC 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 study Variable history CDC source

DMQADFC

Compatible with harmonizationmoderate confidence

Demographics

Did {you/SP} ever serve in a foreign country during a time of armed conflict or on a humanitarian or peace-keeping mission? (This would include National Guard or reserve or active duty monitoring or conducting peace keeping operations in Bosnia and Kosovo, in the Sinai between Egypt and Israel, or in response to the 2004 tsunami or Haiti in 2010.)

Source releases: 4
Available cycles: 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

Relevant boundaries: 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.

Supporting CDC/NCHS evidence

Remove from study Variable history CDC source