Trial Outcomes & Findings for Central Auditory Processing Deficits Associated With Blast Exposure (NCT NCT01567020)

NCT ID: NCT01567020

Last Updated: 2019-06-14

Results Overview

Tests to be administered: Dichotic Digits Test: Percentage of digits reported correctly from 0 (worst performance) to 100 (best performance) Gaps in Noise Test: Approximate threshold in milliseconds from 2 (best) to 20 (worst) Staggered Spondaic Words Test: Total number of errors from 0 (best) to 40 (worst) Masking Level Differences Test: Difference in threshold between diotic and dichotic stimuli in decibels from 0 (worst) to 24 (best) Frequency Pattern Test: Percentage of sequences reported correctly from 0 (worst performance) to 100 (best performance) Adaptive Tests of Temporal Resolution: Not reported due to software error in stimulus presentation

Recruitment status

COMPLETED

Target enrollment

105 participants

Primary outcome timeframe

six months

Results posted on

2019-06-14

Participant Flow

Participant milestones

Participant milestones
Measure
Control
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Overall Study
STARTED
28
46
20
11
Overall Study
COMPLETED
21
41
18
10
Overall Study
NOT COMPLETED
7
5
2
1

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Central Auditory Processing Deficits Associated With Blast Exposure

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Control
n=21 Participants
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
n=41 Participants
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
n=18 Participants
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
n=10 Participants
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Total
n=90 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
0 Participants
n=21 Participants
Age, Categorical
Between 18 and 65 years
21 Participants
n=5 Participants
41 Participants
n=7 Participants
18 Participants
n=5 Participants
8 Participants
n=4 Participants
88 Participants
n=21 Participants
Age, Categorical
>=65 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
2 Participants
n=4 Participants
2 Participants
n=21 Participants
Age, Continuous
31.4 years
STANDARD_DEVIATION 8.5 • n=5 Participants
38.4 years
STANDARD_DEVIATION 11.8 • n=7 Participants
40.4 years
STANDARD_DEVIATION 10.9 • n=5 Participants
56.4 years
STANDARD_DEVIATION 5.5 • n=4 Participants
38.82 years
STANDARD_DEVIATION 12.3 • n=21 Participants
Sex: Female, Male
Female
7 Participants
n=5 Participants
2 Participants
n=7 Participants
2 Participants
n=5 Participants
3 Participants
n=4 Participants
14 Participants
n=21 Participants
Sex: Female, Male
Male
14 Participants
n=5 Participants
39 Participants
n=7 Participants
16 Participants
n=5 Participants
7 Participants
n=4 Participants
76 Participants
n=21 Participants
Region of Enrollment
United States
21 Participants
n=5 Participants
41 Participants
n=7 Participants
18 Participants
n=5 Participants
10 Participants
n=4 Participants
90 Participants
n=21 Participants

PRIMARY outcome

Timeframe: six months

Population: Note that some of the participants finished all of the primary outcome measures but withdrew without finishing all of the secondary tests. They are thus listed as having withdrawn but are still included here for completeness.

Tests to be administered: Dichotic Digits Test: Percentage of digits reported correctly from 0 (worst performance) to 100 (best performance) Gaps in Noise Test: Approximate threshold in milliseconds from 2 (best) to 20 (worst) Staggered Spondaic Words Test: Total number of errors from 0 (best) to 40 (worst) Masking Level Differences Test: Difference in threshold between diotic and dichotic stimuli in decibels from 0 (worst) to 24 (best) Frequency Pattern Test: Percentage of sequences reported correctly from 0 (worst performance) to 100 (best performance) Adaptive Tests of Temporal Resolution: Not reported due to software error in stimulus presentation

Outcome measures

Outcome measures
Measure
Control
n=22 Participants
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
n=42 Participants
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
n=14 Participants
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
n=11 Participants
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Number of Blast-exposed Veterans With Abnormal Abilities in One or More Behavioral Tests of Central Auditory Processing
Staggerred Spondaic Words (Total Errors)
2.1 units on a scale
Standard Deviation 1.8
7.9 units on a scale
Standard Deviation 7.7
5 units on a scale
Standard Deviation 6.04
4.1 units on a scale
Standard Deviation 2.4
Number of Blast-exposed Veterans With Abnormal Abilities in One or More Behavioral Tests of Central Auditory Processing
Dichotic Digits (RE)
99.1 units on a scale
Standard Deviation 1.23
95.2 units on a scale
Standard Deviation 5.5
96.6 units on a scale
Standard Deviation 3.3
97.5 units on a scale
Standard Deviation 3.2
Number of Blast-exposed Veterans With Abnormal Abilities in One or More Behavioral Tests of Central Auditory Processing
Gaps in Noise (RE)
4.7 units on a scale
Standard Deviation 1.1
6.4 units on a scale
Standard Deviation 2.2
5.6 units on a scale
Standard Deviation 1.7
4.7 units on a scale
Standard Deviation 1.5
Number of Blast-exposed Veterans With Abnormal Abilities in One or More Behavioral Tests of Central Auditory Processing
Frequency Pattern Test (RE)
95.5 units on a scale
Standard Deviation 8.6
86.8 units on a scale
Standard Deviation 15.5
84.3 units on a scale
Standard Deviation 21.1
90.3 units on a scale
Standard Deviation 10.8
Number of Blast-exposed Veterans With Abnormal Abilities in One or More Behavioral Tests of Central Auditory Processing
Masking Level Difference
13.4 units on a scale
Standard Deviation 2.9
12.1 units on a scale
Standard Deviation 2.5
12 units on a scale
Standard Deviation 2.4
9.8 units on a scale
Standard Deviation 2.8

SECONDARY outcome

Timeframe: six months

Population: Not all participants were available for further testing.

Hearing Health Inventory for Adults is a 25 item questionnaire that asks participants to rank how often auditory issues create problems in daily life. Scores range from 0 to 100, with higher scores indicating greater perceived levels of handicap.

Outcome measures

Outcome measures
Measure
Control
n=13 Participants
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
n=16 Participants
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Ratings of Self-reported Ability to Process Auditory Information in Various Settings
6.75 score on a scale
Standard Deviation 12.8
32.5 score on a scale
Standard Deviation 31.33

SECONDARY outcome

Timeframe: six months

Population: Not all participants were available for further testing.

The Functional Hearing Questionnaire (FHQ), developed for veterans with brain injuries was used to evaluate self perceived hearing difficulties. The FHQ is a nine item questionnaire that asks participants to rate their level of difficulty hearing in different circumstances on a four point scale. Scores range from 9 to 36, with higher scores indicating a greater level of difficulty.

Outcome measures

Outcome measures
Measure
Control
n=13 Participants
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
n=16 Participants
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Functional Hearing Ability in Multitalker Environments
15.2 scores on a scale
Standard Deviation 3.9
19.9 scores on a scale
Standard Deviation 6.1

SECONDARY outcome

Timeframe: six months

Population: This analysis was only conducted on a subset of the sample, as not all were available for further testing.

Average change in amplitude of the P2 component of the electrophysiological response to paired clicks. Habituation to the clicks is anticipated, resulting in a large percentage change in amplitude to the second click.

Outcome measures

Outcome measures
Measure
Control
n=16 Participants
Non-blast-exposed and non-TBI, aged younger than 50 Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Blast
n=13 Participants
Blast-exposed with or without a TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Non-Blast-Exposed TBI
Non-blast-exposed with TBI diagnosis Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Older
Non-blast-exposed and non-TBI, aged 50 or older Diagnostic: All participants will be evaluated with a battery of behavioral and electrophysiological measures to assess central auditory processing abilities.
Percent Change in P2 Component of Electrophysiological Response
65.74 Percent Change
Standard Deviation 13.8
51.87 Percent Change
Standard Deviation 16

Adverse Events

Control

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Blast

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Non-Blast-Exposed TBI

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Older

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Frederick Gallun

VA Portland Health Care System

Phone: 5032208262

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place