Association between extremely long working hours and musculoskeletal symptoms: A nationwide survey of medical residents in South Korea.
OBJECTIVES It has been reported that South Korea ranked as one of the longest-working nations among OECD countries. This study sought to examine the association between long working hours and musculoskeletal pain among Korean medical residents. METHODS We analyzed a cross-sectional survey of 1,077 medical residents in South Korea. Working hours per week were categorized as follows: <60, 60-79, 80-99, and ≥100. Musculoskeletal pains (ie, upper limb, lower limb, and low back pain) over the past 3 months were categorized into three groups: no pain, pain without interfering with work, and pain interfering with work. Multinomial logistic regression was used to examine the association between long working hours and musculoskeletal pains after adjusting for covariates. RESULTS We found that the average working hours of medical resident was 85.6 hours per week in South Korea. Compared to the medical residents working <60 hours, those working ≥100 hours per week were more likely to have upper limb pain (PR: 1.77, 95% CI: 1.37, 2.30) interfering with work or low back pain (PR: 2.15, 95% CI: 1.51, 3.06) interfering with work, whereas no statistically significant association was observed in the analysis of lower limb pain. CONCLUSIONS This study suggests that extremely long working hours are associated with upper limb and low back pain interfering with their work among Korean medical residents.