Trial Outcomes & Findings for The Effect of Low-Level Laser Stimulation on Hearing Thresholds (NCT NCT01820416)
NCT ID: NCT01820416
Last Updated: 2017-06-01
Results Overview
Hearing status, as assessed by the Connected Sentence Test (CST). Difference scores (post-test - pretest) are reported. The CST approximates everyday conversation. Scoring is based on the number of correctly repeated key words. Higher numbers indicate better scores. The minimum score is 0 (0%) and the maximum is 100 (100%). When comparing test-retest scores for an individual, Cox et al. (1988) suggest that changes of 15% or more (based on 100 key words) are indicative of significant changes. We subtracted the post-test from the pre-test, so that negative difference scores indicate worse performance, and positive difference scores indicate better performance. Difference scores with an absolute value smaller than 15 are interpreted as no significant change. In addition, pre- and post-test performance was assessed for groups using t-tests on the difference scores.
TERMINATED
NA
35 participants
7-10 days after baseline measures recorded
2017-06-01
Participant Flow
Participant milestones
| Measure |
Low-Level Laser Therapy
Low-level laser applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Low-level Laser Therapy: Portable unit containing two laser diodes producing 532 and 635 nm wavelengths. Both diodes produced energy levels of 7.5 mw (class IIIb). Beams from both diodes were dispersed through lenses to create parallel line-generated beams, rather than spots. The 532 nm light was constant, and the 635 nm light was pulsed, with frequencies of 15 and 33 Hz. The pulsing alternated between frequencies every 30 seconds.
|
Disabled Laser
Low-level laser device with laser diodes disabled. Also applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Placebo Comparator: Disabled Laser: Portable unit containing two DISABLED laser diodes. Same protocol was followed as for the Experimental (radiation) group, except that the disabled diodes produced no radiation.
|
Control
Visit laboratory using same schedule as experiment and placebo. No Low-level laser or any treatment applied. Used to assess normal test-retest variability.
|
|---|---|---|---|
|
Overall Study
STARTED
|
12
|
12
|
11
|
|
Overall Study
COMPLETED
|
9
|
10
|
11
|
|
Overall Study
NOT COMPLETED
|
3
|
2
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Race and Ethnicity were not collected from any participant.
Baseline characteristics by cohort
| Measure |
Low-Level Laser Therapy
n=12 Participants
Low-level laser applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Low-level Laser Therapy: Portable unit containing two laser diodes producing 532 and 635 nm wavelengths. Both diodes produced energy levels of 7.5 mw (class IIIb). Beams from both diodes were dispersed through lenses to create parallel line-generated beams, rather than spots. The 532 nm light was constant, and the 635 nm light was pulsed, with frequencies of 15 and 33 Hz. The pulsing alternated between frequencies every 30 seconds.
|
Disabled Laser
n=12 Participants
Low-level laser device with laser diodes disabled. Also applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
|
Control
n=11 Participants
Visit laboratory using same schedule as experiment and placebo. No Low-level laser or any treatment applied. Used to assess normal test-retest variability.
|
Total
n=35 Participants
Total of all reporting groups
|
|---|---|---|---|---|
|
Age, Continuous
|
51.33 years
STANDARD_DEVIATION 15.37 • n=12 Participants
|
55.58 years
STANDARD_DEVIATION 11.42 • n=12 Participants
|
47.09 years
STANDARD_DEVIATION 16.71 • n=11 Participants
|
51.46 years
STANDARD_DEVIATION 14.57 • n=35 Participants
|
|
Sex: Female, Male
Female
|
6 Participants
n=12 Participants
|
5 Participants
n=12 Participants
|
5 Participants
n=11 Participants
|
16 Participants
n=35 Participants
|
|
Sex: Female, Male
Male
|
6 Participants
n=12 Participants
|
7 Participants
n=12 Participants
|
6 Participants
n=11 Participants
|
19 Participants
n=35 Participants
|
|
Race and Ethnicity Not Collected
|
—
|
—
|
—
|
0 Participants
Race and Ethnicity were not collected from any participant.
|
|
Region of Enrollment
United States
|
12 participants
n=12 Participants
|
12 participants
n=12 Participants
|
11 participants
n=11 Participants
|
35 participants
n=35 Participants
|
PRIMARY outcome
Timeframe: 7-10 days after baseline measures recordedHearing status, as assessed by the Connected Sentence Test (CST). Difference scores (post-test - pretest) are reported. The CST approximates everyday conversation. Scoring is based on the number of correctly repeated key words. Higher numbers indicate better scores. The minimum score is 0 (0%) and the maximum is 100 (100%). When comparing test-retest scores for an individual, Cox et al. (1988) suggest that changes of 15% or more (based on 100 key words) are indicative of significant changes. We subtracted the post-test from the pre-test, so that negative difference scores indicate worse performance, and positive difference scores indicate better performance. Difference scores with an absolute value smaller than 15 are interpreted as no significant change. In addition, pre- and post-test performance was assessed for groups using t-tests on the difference scores.
Outcome measures
| Measure |
Low-Level Laser Therapy
n=9 Participants
Low-level laser applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Low-level Laser Therapy: Portable unit containing two laser diodes producing 532 and 635 nm wavelengths. Both diodes produced energy levels of 7.5 mw (class IIIb). Beams from both diodes were dispersed through lenses to create parallel line-generated beams, rather than spots. The 532 nm light was constant, and the 635 nm light was pulsed, with frequencies of 15 and 33 Hz. The pulsing alternated between frequencies every 30 seconds.
|
Disabled Laser
n=10 Participants
Low-level laser device with laser diodes disabled. Also applied for approximately 4 minutes to the area around the pinna, the back of the neck, and the top of the head.
Placebo Comparator: Disabled Laser: Portable unit containing two DISABLED laser diodes. Same protocol was followed as for the Experimental (radiation) group, except that the disabled diodes produced no radiation.
|
Control
n=11 Participants
Visit laboratory using same schedule as experiment and placebo. No Low-level laser or any treatment applied. Used to assess normal test-retest variability.
|
|---|---|---|---|
|
Change in Speech Perception
|
-1.571 difference scores
Standard Deviation 6.949
|
2.286 difference scores
Standard Deviation 8.46
|
-2.8 difference scores
Standard Deviation 5.329
|
Adverse Events
Low-Level Laser Therapy
Disabled Laser
Control
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Shawn S Goodman
Dept. of Communication Sciences & Disorders, University of Iowa
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place