NHANES 2025-2026: Protocol Changes From Prior Round

Attachment 3

NHANES 2025-2026: Protocol Changes From

Prior Round

Attachment 3: NHANES 2025-2026: Protocol Changes From Prior Round  

	2021-2023 NHANES	2025-2026 NHANES
Sample Design	No oversampling by race, ethnicity or income PSUs are counties 15 PSUs No maximum number of people per dwelling unit	Oversampling by age and race PSUs are PUMAs 20 PSUs Maximum three people per dwelling unit
Dwelling Unit Eligibility Screening	Multimode screening of dwelling units by web, mail, telephone and in person	In-person screening
Home Interview & Environmental Sample Collection	Conducted in person or by telephone Audio-recorded verbal informed consent Emancipated minors were eligible with proper documentation SPs ages 16-17 years of age were interviewed directly No environmental specimen collection	Conducted in person Video informed consent presentation, with hardcopy “Home Interview Study Statement,” and audio-recorded documentation of consent Minors who do not have an adult who can give permission for them to participate (including emancipated minors) are not eligible to participate All information on SPs under age 18 are collected by proxy Environmental specimen collection of tap water from dwelling unit
MEC Examination	SPs provided copies of MEC Consent Brochure, Health Measurements List, and Child Assent Flyer (if applicable) Signed, electronic consents collected for MEC exam participation and future studies Exams included: Blood Pressure Body Measures (anthropometry) DXA – Body composition Liver elastography Phlebotomy Urine collection ACASI Balance	SP provided copies of MEC Consent Booklet, Detailed List of NHANES Blood and Urine Laboratory Tests, Child Assent Flyer (if applicable). SPs watch Informed Consent Video Signed, electronic consents collected for MEC exam participation, and future studies Exams included: Blood Pressure Body Measures (anthropometry) DXA – Hip & spine Phlebotomy Urine collection ACASI Oral Health Visual Acuity Ophthalmology Respiratory–Spirometry HPV–Oral rinse and genital swab Hearing
Biospecimen Storage	No DNA storage	No DNA storage
Dietary Interviews	Completed by telephone after MEC exam Included the 30-days Dietary Supplements and Antacids module. FCBS phone follow-up module completed after second dietary interview Informed Consent completed as part of MEC Informed Consent process	Completed by telephone either before or after MEC exam Included the 30-days and the 24-hour Dietary Supplements and Antacids module. FCBS phone follow-up module completed after first dietary interview Informed Consent completed by telephone prior to administration of dietary interviews

Note: ACASI = audio computer-assisted self-interview; FCBS = Flexible Consumer Behavior Survey; MEC = Mobile Examination Center; PSU = Primary Sampling Unit; PUMA = Public Use Microdata Area; SP = Survey Participant.

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