Large Swedish study finds Carpal tunnel syndrome symptoms in surprising group of workers

Researchers gathered data from 2,465 people via questionnaires, nerve tests or physical exams.

SEATTLE — Interesting and surprising results from a recent population study of 2,465 Swedish workers and their risk for carpal tunnel syndrome may end the debate regarding whether a positive connection exists between the condition and keyboard use.

Among persons of working age, a team of Swedish researchers found a 2.6% prevalence of carpal tunnel syndrome (CTS) in individuals who used a keyboard for their jobs more than 4 hours per day. However, they detected a much higher prevalence of 5.2% for those who did not use keyboards at work (P=.032).

"Intense keyboard use at work seems to be associated with a lower risk of CTS," said Isam Atroshi, MD, PhD, of Hässleholm, Sweden, who presented results of the study at the American Society for Surgery of the Hand 62nd Annual Meeting, here.

Researchers found a 2.9% CTS prevalence in workers who used a keyboard for 1 to 4 hours per day and 4.9% in those who used a keyboard less than 1 hour per day.

They initially identified subjects via a questionnaire that asked about work factors and pain and/or numbness. They then performed physical exams and nerve conduction studies to confirm and diagnose CTS in those who responded that they had symptoms and who were willing to enter the study.

The researchers defined CTS as the presence of symptoms of recurrent and verified pain, numbness and tingling, and abnormal nerve study results.

Atroshi said the study's weaknesses included its cross-sectional nature, which prevented showing a direct relationship between keyboard use and CTS. It also relied on self-reported data.

However, any outside activities or work that participants did, including side jobs, hobbies or keyboarding at home, were likely not a significant factor, he noted.

For more information:
Isam Atroshi, MD, PhD, has indicated his study received support from the Skane County Council's Research and Development Foundation and Kristianstad University, Sweden.
Atroshi I, Gummesson C, Ornstein E, et al. Carpal tunnel syndrome and keyboard use at work: Population-based study. #20. Presented at the 62nd Annual Meeting of the American Society for Surgery of the Hand. Sept. 27-29, 2007. Seattle.
Atroshi I, Gummesson C, Johnsson R, et al. Prevalence of carpal tunnel syndrome in a general population. JAMA. 1999; 282:153-158.