Praxis Data Lab · Study Builder
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.
Praxis found harmonization conditions for this study and has surfaced them below with the supporting source evidence.
4 variable assessments
Laboratory
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
Questionnaire
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: 2017-2018 → 2017-2020
Examination
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
Demographics
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: 2017-2020 → 2021-2023