Uniform Data Set version 4
UDSv4 - Template

United States

Reference ID

USDv4

Producer(s)

National Alzheimer’s Coordinating Center (NACC) and the NIA-funded ADRC network

Collections

Clinical Trial

Metadata

DDI/XML JSON

Created on

Jul 02, 2026

Last modified

Jul 07, 2026

Page views

11404

Variable Groups

Variable group: A2 Co-participant demographics

Variables 20

a2_coparticipant_demographi
cs_complete

a2not

0d2. If 'A2 Co-Participant Demographics' not submitted, specify reason

frmdatea2

0a. A2 Co-Participant Demographics - Form date

incntfrq

IVP Q4a1./FVP Q5a1. What is the approximate frequency of all types of contact?

incntmdx

Other (SPECIFY):

incntmod

IVP Q4./FVP Q5. What is the primary mode of contact with the participant?

incnttim

IVP Q4a2./FVP Q5a2. What is the average amount of time spent in contact with the participant during each encounter? (Please include an average of all encounter types)

initialsa2

0b. A2 Co-Participant Demographics - Examiner's initials

inknown

IVP Q2./FVP Q3. How long has the co-participant known the participant? (If the co-participant has known the participant for less than 1 year, use 0.)

inlivwth

IVP Q3./FVP Q4. Does the co-participant live with the participant?

inmemten

IVP Q8./FVP Q9. Compared to 10 years ago, would you say that the participant's memory is much worse, a little worse, the same, a little better, or much better?

inmemtroub

IVP Q7./FVP Q8. About how often does the participant have trouble remembering things?

inmemwors

IVP Q6./FVP Q7. Do you feel like the participant's memory is becoming worse?

inrelto

IVP Q1./FVP Q2. What is the co-participant's relationship to the participant?

inrely

IVP Q5./FVP Q6. Is there a question about the co-participant's reliability?

langa2

0c. A2 Co-Participant Demographics - Language

modea2

0d. A2 Co-Participant Demographics - In-person, remote, or not completed?

newinf

1. Is this a new co-participant (i.e., one who was not a co-participant at any past UDS visit)?

rmmodea2

0d1a. What modality was used to collect this remote 'A2 Co-Participant Demographics' form?

rmreasa2

0d1. If 'A2 Co-Participant Demographics' form was completed remotely, specify reason

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