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The Effect of Alternative Keyboards on Discomfort and Typing Kinematics

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ClinicalTrials.gov Identifier: NCT00801983
Recruitment Status : Completed
First Posted : December 4, 2008
Results First Posted : August 22, 2014
Last Update Posted : August 22, 2014
Sponsor:
Collaborator:
National Institute for Occupational Safety and Health (NIOSH/CDC)
Information provided by (Responsible Party):
Nancy Baker, University of Pittsburgh

Study Type Interventional
Study Design Allocation: Randomized;   Intervention Model: Crossover Assignment;   Masking: None (Open Label);   Primary Purpose: Prevention
Condition Pain
Intervention Device: Alternative Keyboard
Enrollment 85
Recruitment Details  
Pre-assignment Details  
Arm/Group Title Group A (Typical/Alternative) Group B (Alternative/Typical)
Hide Arm/Group Description Subject receives typical keyboard for 5-6 months first and alternative keyboard second for 5-6 months (total 12 months in study Subject receives alternate keyboard for 5-6 months first and typical keyboard second for 5-6 months (total 12 months in study
Period Title: Period 1
Started 44 41
Completed 40 33
Not Completed 4 8
Reason Not Completed
Lost to Follow-up             2             0
Withdrawal by Subject             2             8
Period Title: Period 2
Started 40 33
Completed 38 32
Not Completed 2 1
Reason Not Completed
Withdrawal by Subject             2             1
Arm/Group Title Group A Group B Total
Hide Arm/Group Description Subject receives typical keyboard first (0-6 months) and alternative keyboard second (7-12 months). In this crossover design all subjects received both standard and alternative keyboard, each group just received the keyboards in a different order Subject receives alternative keyboard first (0-6 months) and typical keyboard second (7-12 months). In this crossover design all subjects received both standard and alternative keyboard, each group just received the keyboards in a different order Total of all reporting groups
Overall Number of Baseline Participants 40 37 77
Hide Baseline Analysis Population Description
GEE analyses allows a subjects inclusion even if they did not complete the full trial. Although we had a total of 15 subjects not complete the full trial we had sufficient data on 77 subjects to complete the GEE statistical analyses. With the crossover design we compared 77 subjects using the standard keyboard to 77 subjects using the alternative
Age, Continuous  
Mean (Standard Deviation)
Unit of measure:  Years
Number Analyzed 40 participants 37 participants 77 participants
43.3  (12.9) 45.6  (11.9) 44.4  (12.4)
Sex: Female, Male  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 40 participants 37 participants 77 participants
Female
36
  90.0%
35
  94.6%
71
  92.2%
Male
4
  10.0%
2
   5.4%
6
   7.8%
Race (NIH/OMB)  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 40 participants 37 participants 77 participants
American Indian or Alaska Native
0
   0.0%
0
   0.0%
0
   0.0%
Asian
1
   2.5%
0
   0.0%
1
   1.3%
Native Hawaiian or Other Pacific Islander
0
   0.0%
0
   0.0%
0
   0.0%
Black or African American
3
   7.5%
5
  13.5%
8
  10.4%
White
36
  90.0%
31
  83.8%
67
  87.0%
More than one race
0
   0.0%
1
   2.7%
1
   1.3%
Unknown or Not Reported
0
   0.0%
0
   0.0%
0
   0.0%
Ethnicity (NIH/OMB)  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 40 participants 37 participants 77 participants
Hispanic or Latino
1
   2.5%
0
   0.0%
1
   1.3%
Not Hispanic or Latino
39
  97.5%
37
 100.0%
76
  98.7%
Unknown or Not Reported
0
   0.0%
0
   0.0%
0
   0.0%
Region of Enrollment  
Measure Type: Number
Unit of measure:  Participants
United States Number Analyzed 40 participants 37 participants 77 participants
40 37 77
Avg Computer Use  
Mean (Standard Deviation)
Unit of measure:  Hrs/day
Number Analyzed 40 participants 37 participants 77 participants
6.3  (1.1) 6.1  (1.5) 6.2  (1.3)
Typing Speed  
Measure Type: Number
Unit of measure:  Participants
Number Analyzed 40 participants 37 participants 77 participants
Slow 7 3 10
Moderately Fast 16 14 30
Fast 11 12 23
Don't know 6 8 14
Baseline Discomfort  
Measure Type: Number
Unit of measure:  Participants
Number Analyzed 40 participants 37 participants 77 participants
Neck (Yes) 36 36 72
Back (Yes) 33 33 66
Right arm hand (Yes) 33 36 69
Left Arm hand (Yes) 22 24 46
1.Primary Outcome
Title Musculoskeletal Discomfort
Hide Description

Discomfort Survey (WDS) was used to assess symptoms and activity limitations. Participants reported on their work schedule, medication used for pain control, and discomfort in their neck/shoulder, back, and bilateral lower arms (elbows, forearms, wrists, and hands) using an 11-point numerical rating scale (0 = no discomfort/no limitations; 10 = unbearable discomfort/major limitations).

We had to dichotomize the data during analysis due to severe skew towards not discomfort (0). Thus the final outcome was discomfort -yes or no

Time Frame 6 months and 12 months
Show Outcome Measure DataHide Outcome Measure Data
Hide Analysis Population Description
[Not Specified]
Arm/Group Title Typical Keyboard Alternative Keyboard
Hide Arm/Group Description:
MSD reported when a subject was typing on a typical keyboard (regardless of order)
MSD reported when a subject was typing on an alternative keyboard (regardless of order)
Overall Number of Participants Analyzed 77 77
Measure Type: Number
Unit of Measure: percentage of subjects with MSD
20 20
Show Statistical Analysis 1 Hide Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Typical Keyboard, Alternative Keyboard
Comments Subjects were compared across keyboard types - The percentage of subjects with MSD when using the alternative keyboard were compared to the % of subjects with MSD when they were using the typical keyboard
Type of Statistical Test Superiority or Other
Comments [Not Specified]
Statistical Test of Hypothesis P-Value >.05
Comments [Not Specified]
Method GEE
Comments [Not Specified]
Time Frame [Not Specified]
Adverse Event Reporting Description [Not Specified]
 
Arm/Group Title Typical Keyboard Alternative Keyboard
Hide Arm/Group Description MSD reported when a subject was typing on a typical keyboard (regardless of order) MSD reported when a subject was typing on an alternative keyboard (regardless of order)
All-Cause Mortality
Typical Keyboard Alternative Keyboard
Affected / at Risk (%) Affected / at Risk (%)
Total   --/--   --/-- 
Show Serious Adverse Events Hide Serious Adverse Events
Typical Keyboard Alternative Keyboard
Affected / at Risk (%) Affected / at Risk (%)
Total   0/85 (0.00%)   0/85 (0.00%) 
Show Other (Not Including Serious) Adverse Events Hide Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events 0%
Typical Keyboard Alternative Keyboard
Affected / at Risk (%) Affected / at Risk (%)
Total   0/85 (0.00%)   0/85 (0.00%) 
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
Name/Title: Dr. Nancy Baker
Organization: University of Pittsburgh
Phone: 412 383-6607
Responsible Party: Nancy Baker, University of Pittsburgh
ClinicalTrials.gov Identifier: NCT00801983     History of Changes
Other Study ID Numbers: 08030467
R01OH008961 ( U.S. NIH Grant/Contract )
First Submitted: December 3, 2008
First Posted: December 4, 2008
Results First Submitted: May 19, 2014
Results First Posted: August 22, 2014
Last Update Posted: August 22, 2014