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.
Source-linked evidence · Hourly surveillance · Validated publication
CollectionNHANES
Indexed eraContinuous NHANES · 1999–present
Preparation levelsSource · Standardized
Publication standardValidated · Reviewed
Praxis intelligence status
Evidence you can inspect. Updates you can trust.
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
1,800Continuous NHANES dataset releases indexed
58,817variable evidence records
69,851documented change events
47,829harmonization assessments
Headline counts reflect the latest validated intelligence release. Harmonization assessments combine variable-level and cycle-boundary assessments; they do not represent unique variables. Times are shown in your local timezone. Read the source, coverage, and research-use notice. Inspect the first public Validation Record.
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.
Statistical context
Survey design, eligibility, weighting, subsample, and cycle requirements remain visible for study-specific decisions.
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 brings those requirements into view so researchers can evaluate them with greater clarity and confidence.
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