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

14512

4g1. Indicate the source(s) of exposure for repeated hits to the head (Select all that apply) (loc_imp)

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

Overview

Valid: 52

Range: -

Format:

Questions and instructions

Question pretext

[headimp]='1'

Categories

Value	Category	Cases
impamfoot	4g1a. American football	9	17.3%
impsoccer	4g1b. Soccer	5	9.6%
imphockey	4g1c. Ice Hockey	2	3.8%
impboxing	4g1d. Boxing or mixed martial arts	8	15.4%
impsport	4g1e. Other contact sport	5	9.6%
impipv	4g1f. Intimate partner violence	5	9.6%
impmilit	4g1g. Military service	7	13.5%
impassault	4g1h. Physical assault	10	19.2%
impother	4g1i. Other(SPECIFY) {impotherx}	1	1.9%

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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