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.

2variables selected
Praxis harmonization guidance available

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

2 variable assessments

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

RIDRETH1
Compatiblehigh confidence

Demographics

Recode of reported race and ethnicity information.

Source releases
16
Available cycles
1999-2000 · 2001-2002 · 2003-2004 · 2005-2006 · 2007-2008 · 2009-2010 · 2009-2010 · 2009-2010 · 2009-2010 · 2009-2010 · 2011-2012 · 2013-2014 · 2015-2016 · 2017-2018 · 2017-2020 · 2021-2023
Dataset
Demographic Variables & Sample Weights

RIDRETH1 is retained as the longitudinal five-category race/Hispanic-origin recode, including after the expanded RIDRETH3 variable was introduced in 2011-2012. CDC/NCHS specifically retained RIDRETH1 to support comparison with earlier Continuous NHANES cycles.

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

Evidence signals: source-stated

Praxis harmonization actions
  • Use RIDRETH1 when a common five-category race/Hispanic-origin construct is required across earlier and later cycles. Apply survey-design requirements separately and do not substitute RIDRETH3 categories without an explicit recode.
Supporting CDC/NCHS evidence