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

14905

Study Description
Data Dictionary

2a6. If clinical trial, in which group was the participant? (1) (trialgrp1)

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

Overview

Valid: 60

Range: -

Format:

Questions and instructions

Question pretext

[trtbiomark]='1' and [caretrial1]>'1'

Categories

Value	Category	Cases
1	Active treatment	28	46.7%
2	Placebo	23	38.3%
9	Unknown	9	15%

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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