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

BMXBMI
Compatiblehigh confidence

Examination

Body Mass Index (kg/m**2)

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
Body Measures

CDC/NCHS documentation supports continuity of the core NHANES anthropometry protocol across Continuous NHANES. BMI remains the derived construct of weight in kilograms divided by standing height in meters squared. Indexed differences for this variable are limited to dataset context and documentation wording, not a confirmed measurement or calculation discontinuity.

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

Evidence signals: source-stated

Praxis harmonization actions
  • Pool BMI across calibrated cycles without a method adjustment when no substantive variable-level change is present. Continue to apply cycle-appropriate NHANES weights, eligibility restrictions, and ordinary analytic guidance.
Supporting CDC/NCHS evidence