Source fidelity
Original files, documentation, retrieval context, and SHA-256 hashes remain linked to every release.
Praxis Data Lab · NHANES Collection
Public health data, prepared with rigor.
Discover, inspect, and obtain research datasets with their provenance, survey design, documentation, and preparation decisions intact.
Independent from CDC/NCHS · Built for researchers, analysts, and public institutions
CollectionNHANES
Indexed eraContinuous NHANES · 1999–present
Preparation levelsSource · Standardized
Publication standardValidated · Reviewed
Praxis intelligence status
Evidence you can inspect. Freshness you can see.
Validated intelligence available
CDC/NCHS source watchdogContinuous source surveillance active
Praxis monitors CDC/NCHS sources every hour for changes. The latest validated intelligence is available and ready to use.
Last source check
Monitored source endpoints65
Latest surveillance resultMonitoring active
Source surveillanceEvery hour · HH:00 UTC
Change responseAutomatic refresh and validation before publication
Weekly full refreshMonday · 00:00 UTC
Next weekly refresh · your time
Last validated refresh · your time
SourceCDC/NCHS
Coverage99.44%
Harmonization enginev0.3.2
99.44%
Validated source coverageContinuous NHANES indexed against CDC/NCHS source evidence
1,796Continuous NHANES dataset releases indexed
58,780variable evidence records
69,813documented change events
47,797harmonization assessments
Praxis continuously monitors CDC/NCHS source indexes for changes. Source surveillance runs hourly, while the validated intelligence corpus is refreshed every Monday at 00:00 UTC and whenever a confirmed source update requires rebuilding. Published intelligence remains tied to the most recently validated release. Headline counts reflect that validated harmonization release and may change as source coverage and scientific validation improve. Times are shown in your local timezone. Current indexed harmonization coverage begins with Continuous NHANES in 1999; earlier NHES and periodic NHANES I–III historical surveys are not yet included in this corpus.
The Praxis standard
Every dataset should carry its evidence.
We reduce repetitive preparation work while keeping the source, transformations, limitations, and statistical responsibilities visible.
Explicit preparation
Source, standardized, curated derivative, and analysis-template levels are never collapsed into one ambiguous label.
Release accountability
Recipes, pipeline versions, validation outcomes, approvals, and prior versions remain inspectable.
Scientific restraint
No derivative is represented as statistically correct for every population, component, or research question.
Responsible research use
Prepared for access. Never stripped of context.
NHANES analyses may require component-specific eligibility rules, interview or examination weights, fasting or laboratory subsample weights, strata, PSUs, and multi-cycle adjustments.
Praxis makes those decisions easier to find. It does not replace study-specific statistical judgment.
Inspect the pilot catalog