Occupational carpal tunnel syndrome in Washington state, 1984-1988

Background: There are no published population-based studies of occupational carpal tunnel syndrome (OCTS) using a strict case definition. Most studies are either industry specific or present patient self-report of symptoms. Methods: We conducted a population-based incidence study of OCTS using the Washington State Workers' Compensation database. Incident OCTS claims were identified with paid bills for physician reported ICD codes 354.0 and 354.1. Results: There were 7,926 incident OCTS claims identified for the years 1984-1988, which yields an industry-wide incidence rate of 1.74 claims/1,000 FTEs. The mean age (37.4 years) and female/male ratio (1.2:1) in this population differ from those reported in nonoccupational carpal tunnel studies (mean age, 51 years; female/male ratio, 3:1). The female-specific OCTS incidence rate increased significantly during the study period. The highest industry specific OCTS rates were found in the food processing, carpentry, egg production, wood products, and logging industries. Conclusion: Demographic differences and industry-specific rates consistent with workplace exposures suggest that OCTS is distinct from CTS occurring in nonoccupational settings. Workers' compensation data proved useful in identifying high risk industries.