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

ACD010C
Compatible with harmonizationmoderate confidence

Questionnaire

What language(s) {do you/does SP} usually speak at home?

Source releases
7
Available cycles
1999-2000 · 2001-2002 · 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2021-2023
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 · 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 → 2021-2023

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.
  • Confirm that the construct and coding are unchanged before pooling or recoding.
Supporting CDC/NCHS evidence
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
INDFMPIR
Compatible with harmonizationmoderate confidence

Demographics

Poverty income ratio (PIR) - a ratio of family income to poverty threshold

Source releases
12
Available cycles
1999-2000 · 2001-2002 · 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2017-2020 · 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 · 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 · 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.
  • 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.
  • Confirm that the construct and coding are unchanged before pooling or recoding.
Supporting CDC/NCHS evidence