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

13015

Study Description
Data Dictionary

3. In the past 30 days, how often were you not able to leave the house when you wanted to because of a problem with transportation? (transprob)

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

Overview

Valid: 56

Range: -

Format:

Questions and instructions

Question pretext

[modea1a] <> '0'

Categories

Value	Category	Cases
1	Often	16	28.6%
2	Sometimes	8	14.3%
3	Never	15	26.8%
8	Prefer not to answer	17	30.4%

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.

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