We investigated the differences among the patients who were diagnosed with carpal tunnel syndrome according to the frequency of exposure to wrist-burdening work by using carpal tunnel syndrome surveillance system.

The study subjects were a total of 855 patients from 1,017 patients who were diagnosed with carpal tunnel syndrome in 9 university hospitals from May, 2001 to October, 2004, and we excluded 161 patients who had no clear information for their occupational status. The subjects were classified into three groups according to four types of wrist-burdening work: 1) repetitive use of wrists, 2) inappropriate posture of the hand, 3) use of vibrating tools, and 4) overpressure work on the hand or palm, - as defined in the operational definition by the National Institute for Occupational Safety and Health (NIOSH). The subjects with two or more types of wrist-burdening work were classified as 'high risk group', the subjects with one type of wrist-burdening work were classified as 'intermediate risk group', and the subjects with none of the types of wrist-burdening work were classified as 'low risk group'. We used chi-square test, Fisher's exact test and ANOVA for comparing the characteristics according to the 3 subgroup.

The mean age in the high risk group was the lowest(53 years), and there was a significant difference among the groups for the mean age(p<0.05). The high risk group included the most males with 39(22.0%). The subjects in the high risk group had significantly more jobs in agriculture·forestry·fisheries, factory work, and simple labor and less comorbidities, including diabetes and rheumatoid arthritis(p<0.05). The subjects in the intermediate risk group had a higher proportion of service workers. There were significant differences for the symptoms of carpal tunnel syndrome according to the frequency of exposure to wrist-burdening work. The subjects in the high risk group showed the highest proportion of work-related aggravation of symptoms with 88(76.5%) and the highest mean number of days absent from work(6 days) as related to carpal tunnel syndrome.

Worker in agriculture·forestry·fisheries, factory work, and simple labor showed significantly more frequent carpal tunnel syndrome, and so management strategies are needed to prevent them from developing carpal tunnel syndrome.