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.

Association of social deprivation and outdoor air pollution with pulmonary tuberculosis in spatiotemporal analysis.

The objective of this study was to identify the association between social deprivation, outdoor air pollution, and tuberculosis (TB) incidence rate or mortality rate. The study sample comprised 25 districts in Seoul, Korea. We used two public data derived from the Community Health Survey and Seoul Statistics. The geographic information system analysis and random effects Poisson regression were applied to explore the association of social deprivation and air pollution with TB incidence and mortality. An 1 ppb increase in sulfur dioxide (SO2) concentration was significantly associated with the risk of TB incidence (risk ratio [RR] = 1.046, 95% confidence interval [CI]: 1.028, 1.065). An 1 unit increase in the deprivation index was significantly related to a6% increase in the mortality of TB (RR = 1.063, 95% CI: 1.031, 1.097). : Our results imply that social deprivation and air pollution may affect the different TB outcomes. Effective policy-making for TB control should reflect the differing outcomes between TB incidence and mortality.

Perceived discrimination and low back pain among 28,532 workers in South Korea: Effect modification by labor union status.

OBJECTIVES: This study investigated the association between workplace discrimination and low back pain among Korean workers and explored the role of labor union in the association. METHODS: We analyzed a cross-sectional survey of 28,532 workers from the 3rd Korean Working Conditions Survey (2011), a nationally representative dataset in South Korea. Experience of workplace discrimination for five different reasons was assessed using the questions: "Over the past 12 months, have you ever experienced workplace discrimination based on your: (a) age, (b) education, (c) birth region, (d) sex, and (e) employment status?" Experience of low back pain within a 12 month period was measured using a yes/no question. Labor union membership was coded into three categories: (1) workers at workplaces without a labor union; (2) workers without union membership at workplaces with a labor union; (3) workers with union membership. RESULTS: In workplaces without a labor union, low back pain was statistically significantly associated with workplace discrimination based on age (OR: 2.02, 95% CI: 1.73, 2.35), education (OR: 1.45, 95% CI: 1.23, 1.71), birth region (OR: 1.42, 95% CI: 1.10, 1.84), sex (OR: 2.22, 95% CI: 1.81, 2.73), and employment status (OR: 2.33, 95% CI: 1.99, 2.72) after adjusting for covariates including physical work factors. However, no significant association was observed among workers at workplaces with a labor union regardless of workers' union membership. CONCLUSIONS: Workplace discrimination was associated with low back pain only in workplaces without a labor union. Presence of labor union at workplaces may have a protective effect on workers' low back pain against workplace discrimination.