Association between handedness and occupational accidents: a prospective cohort study

This study aimed to investigate the association between handedness and the incidence of occupational accidents among Japanese workers.

A prospective cohort study was conducted from March to December 2023. Among 9451 workers at the baseline, 6156 responded to the follow-up. Participants who reported working fewer than 20 days per month and those with weekly working hours of less than 30 hours were excluded from the analysis, leaving 4016 participants for final analysis. We assessed handedness using the FLANDERS Handedness Questionnaire at baseline and occupational accident experiences at follow-up. We used adjusted Poisson regression analysis to calculate the incidence rate ratio (IRR) of occupational accidents among participants. The multivariate-adjusted model was adjusted for covariates: age, sex, education, industry, working hours, work style (day, shift, night, others), and sleeping time. The IRR and 95% CI were subsequently calculated.

Of the participants, 3646 were right-handed, 193 mixed-handed, and 177 left-handed. Occupational accidents were reported by 181(5.0%) of right-handed, 19 (9.8.%) of mixed-handed, and 11 (6.2%) of left-handed participants. Compared with right-handed participants, the IRR for occupational accidents was significantly elevated in mixed-handed participants (IRR = 1.84; 95% CI, 1.17-2.88). However, no significant difference was observed in left-handed participants (IRR = 1.13; 95% CI, 0.63-2.04).

Mixed-handedness is associated with a higher incidence of occupational accidents. In contrast, left-handedness does not confer additional risk.