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

12052

Study Description
Data Dictionary

28a. Cognitive impairment due to substance use or abuse (primary/contributing/non-contributing) (impsubif)

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

Overview

Valid: 58

Range: -

Format:

Questions and instructions

Question pretext

[loc_impsub(1)] = 1

Categories

Value	Category	Cases
1	Primary	16	27.6%
2	Contributing	22	37.9%
3	Non-contributing	20	34.5%

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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