Gender differences in the association between long work hours, weekend work, and insomnia symptoms in a nationally representative sample of workers in Korea.

Objectives: Long work hours and weekend work can negatively impact worker sleep; however, gender differences in these relationships have not been sufficiently studied. We explored the association between long work hours, weekend work, and insomnia symptoms, as well as the moderating effect of gender on this association.

Methods: A nationwide sample of 42,476 Korean workers (52.8% women) was analyzed. The main exposure variables were weekly work hours and monthly weekend days worked. Insomnia symptoms were measured using the Minimal Insomnia Symptom Scale. Logistic regression was used to estimate odds ratios (ORs) and confidence intervals (CIs).

Results: Among the study sample, 10.5% worked ≥55hours weekly and 9.6% worked ≥5 weekend days monthly. The OR (95% CI) of an association between long work hours and insomnia symptoms was 1.72 (1.48-2.00) for 49-54hours, and 2.01 (1.71-2.37) for ≥55hours among men and 1.26 (1.03-1.55) for 49-54hours, and 1.03 (0.83-1.27) for ≥55hours among women. The OR (95% CI) of an association between monthly weekend days worked and insomnia symptoms was 1.68 (1.50-1.90) for 1-4days and 1.92 (1.62-2.29) for ≥5days among men and 1.20 (1.05-1.36) for 1-4days and 1.54 (1.28-1.86) for ≥5days among women.

Conclusion: Long work hours and weekend work are associated with insomnia symptoms, and this association is more pronounced among men than women. Policy interventions are warranted to reduce the burden of long work hours and weekend work.