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

14192

Study Description
Data Dictionary

1i2. Prior to 12 months ago (substpast)

Data file: UDSv4TemplateForXMLD_2026-04-14_0731.REDCap.xml

Overview

Valid: 58

Range: -

Format:

Questions and instructions

Categories

Value	Category	Cases
0	No	23	39.7%
1	Yes	33	56.9%
9	Unknown	2	3.4%

Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.

Back to Catalog