Computer use and carpal tunnel syndrome: a 1-year follow-up study.
BACKGROUND
Computer use is increasingly common among many working populations, and concern exists about possible adverse effects of computer use, such as carpal tunnel syndrome (CTS).


OBJECTIVE
To estimate the prevalence and incidence of possible CTS and to evaluate the contribution of use of mouse devices and keyboards to the risk of possible CTS.


METHODS
A 1-year follow-up study with questionnaires conducted in 2000 and 2001 at 3500 workplaces in Denmark, followed on each of the 2 occasions by a clinical interview on symptom distribution and frequency.


METHODS
The questionnaire was sent to 9480 members of a trade union, with an initial response rate of 73% (n = 6943), and 82% (n = 5658) at follow-up.


METHODS
At baseline, there were 3 outcome measures: tingling/numbness in the right hand once a week or more as reported in the questionnaire; tingling, numbness, and pain in the median nerve in the right hand confirmed by clinical interview; and tingling, numbness, and pain in the median nerve in the right hand at night confirmed by clinical interview. At 1 year of follow-up the main outcome of interest was onset of symptoms among participants who had no or minor symptoms at baseline.


RESULTS
The overall self-reported prevalence of tingling/numbness in the right hand at baseline was 10.9%. The interview confirmed that prevalence of tingling/numbness in the median nerve was 4.8%, of which about one third, corresponding to a prevalence of 1.4%, experienced symptoms at night. Onset of new symptoms in the 1-year follow-up was 5.5%. In the cross-sectional comparisons and in the follow-up analyses, there was an association between use of a mouse device for more than 20 h/wk and risk of possible CTS but no statistically significant association with keyboard use.


CONCLUSIONS
The occurrence of possible CTS in the right hand was low. The study emphasizes that computer use does not pose a severe occupational hazard for developing symptoms of CTS.
Andersen
Johan Hviid
JH
Department of Occupational Medicine, Herning Hospital, Herning, Denmark. hecjha@ringamt.dk
Thomsen
Jane Froelund
JF
Overgaard
Erik
E
Lassen
Christina Funch
CF
Brandt
Lars Peter Andreas
LP
Vilstrup
Imogen
I
Kryger
Ann Isabel
AI
Mikkelsen
Sigurd
S
D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000453:epidemiology* / Q000209:etiology; D003201:Computers / Q000706:statistics & numerical data*; D006804:Ergonomics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D014584:User-Computer Interface