Abstract
ObjectivesThe aim was to examine exposure–response relations between occupational hand exposures and carpal tunnel syndrome (CTS) and to compare the relation between surgery-treated and non-surgery-treated CTS. The secondary aim was to study sex-specific differences in exposure–response relations.MethodsWe conducted a nationwide register-based cohort study of all persons born in Denmark (1945–1994). During follow-up (2010–2013), we identified first-time events of CTS. Occupational hand exposure estimates the year before each follow-up year were obtained by linking individual occupational codes with a job exposure matrix. We used multivariable logistic regression equivalent to discrete survival analysis based on sex and surgery. The excess fraction of cases was calculated.ResultsFor both sexes, exposure–response relations were found for all occupational hand exposures. Among men, we found ORadjof 3.6 (95% CI 3.2 to 3.8) for hand-related force, 2.9 (95% CI 2.5 to 3.2) for repetitive hand movements, 3.8 (95% CI 2.7 to 5.2) for non-neutral hand posture and 2.5 (95% CI 2.2 to 2.7) for hand-arm vibration in the highest exposure groups. For combined exposure (hand load), ORadjwas 3.5 (95% CI 3.1 to 4.0). Slightly higher ORsadjwere generally found for surgery-treated CTS compared with non-surgery-treated CTS for both sexes. When comparing sex, somewhat higher ORsadjwere found among men. The excess fraction was 42%.ConclusionsOccupational hand exposures carried a 3-5-fold increased risk of CTS with slightly higher risks for surgery-treated compared with non-surgery-treated CTS. Even though CTS occurs more frequently among women, somewhat higher exposure–response relations were found for men compared with women. In the general working population, a substantial fraction of first-time CTS could be related to occupational hand exposures.