Jinwook Bahk

Working Hours and Depressive Symptomatology among Full-Time Employees: Results from the Fourth Korean National Health and Nutrition Examination Survey (2007-2009)

OBJECTIVE This study aimed to examine the distribution of working hours and the association between working hours and depressive symptomatology using representative data from a national, population-based survey. METHOD Data came from the fourth Korean National Health and Nutrition Examination Survey (2007-2009), which employed a systematic, stratified cluster-sampling method. We used logistic regression procedures to estimate the importance of weekly working hours as a predictor of depressive symptomatology. RESULTS The prevalence of depressive symptomatology was 10.2%. The work week, which averaged 48.3 hours for the sample as a whole, was longer for men (49.8 hours) than women (45.3 hours), and 12.1% of respondents were engaged in shift work. In logistic regression analyses, compared to those working < 52 hours per week, the odds ratios (OR) of working hours as a predictor of depressive symptomatology were 1.19 [95% confidence interval (95% CI) 0.77-1.85] for those working 52-59 hours per week and 1.62 (95% CI 1.20-2.18) for those working ≥ 60 hours per week, after adjustment for demographic characteristics, health behaviors, socioeconomic status, employment status, and work schedules. It showed a positive dose-response relationship between working hours and depressive symptomatology (P = 0.0059). CONCLUSIONS Working hours in Korea are long. There is an association between working hours and depressive symptomatology, and there seems be a trend in working hours and depressive symptomatology.

Impact of unintended pregnancy on maternal mental health: a causal analysis using follow up data of the Panel Study on Korean Children (PSKC)

BackgroundPregnancy intention is important for maternal and child health outcomes. The purpose of this study was to examine the causal relation between pregnancy intention and maternal depression and parenting stress in Korean women who gave birth during 2008.MethodsThis study is a retrospective evaluation of prospectively collected data from the Panel Study on Korean Children from 2008 to 2010. Causal analyses were conducted using propensity score matching and inverse probability of treatment weighted methods. In addition, mediation analyses were performed to test mitigating effects of marital conflict, fathers’ participation in childcare, and mothers’ knowledge of infant development on the relation between unintended pregnancy and adverse maternal mental health.ResultsResults showed that the overall effect of an unintended pregnancy on maternal depression and parenting stress was statistically significant. An unintended pregnancy was associated with 20–22% greater odds of maternal depression, 0.28–0.39 greater depression score, and 0.85–1.16 greater parenting stress score. Relations between pregnancy intention and maternal depression, maternal depression score and parenting stress score were moderately explained by marital conflict and fathers’ participation in childcare.ConclusionsUnintended pregnancy contributed to increased risks of maternal depression and parenting stress. Efforts to increase fathers’ participation in childcare and decrease marital conflict might be helpful to mitigate adverse impacts of unintended pregnancy on perinatal maternal mental health.

Age- and cause-specific contributions to income difference in life expectancy at birth: findings from nationally representative data on one million South Koreans

BACKGROUND Income is not frequently used to monitor health equity on a national level largely due to the lack of public data on income. Information on income allows policy makers to identify the economically disadvantaged population in a country directly. We examined differences in life expectancy (LE) at birth by income and quantified age- and cause-specific contributions to the LE differences using national health insurance data. METHODS Data from a nationally representative sample of 1 097 333 South Koreans (2% of the total population) collected between 2002 and 2010 (39 737 deaths) were used. National health insurance premiums were used to estimate income level. Age- and cause-specific contributions to differences in LE at birth by income were estimated using Arriagas decomposition method. RESULTS LE at birth gradually increased with income in both genders. Interquintile income LE differences were 7.93 years in males and 3.82 years in females. Most of LE differentials were attributed to differences in mortality in middle-aged and older adults. Suicide and cerebrovascular accidents were the two leading causes of death contributing the most to income LE differences in both males and females. The top 10 causes of death accounted for over 50% of the total LE differences by income in both genders. Alcohol-related causes of death explained the majority of the gender differences in the income LE differentials. CONCLUSIONS Income differentials in LE at birth according to national health insurance premiums and data linkage systems could provide a valuable opportunity for monitoring and prioritizing population health inequalities in South Korea.

Why some, but not all, countries have banned asbestos

Abstract Background: Out of 143 countries that consumed asbestos between 2003 and 2007, only 44 have banned asbestos. This study tried to explain why some countries have banned asbestos while others have not, based on a synthesis that asbestos ban policy of a country will rely on a process of cognition of threats and exploration of safer alternatives. Method: As we hypothesized that increased social cost of mesothelioma, capacity of health-related infrastructures, and policy diffusion from adjacent countries were related to asbestos ban adoption, published databases of asbestos ban years, mesothelioma mortality, country rankings in health care and human rights standings, and distribution of banning countries over 14 regions were analyzed accordingly. Results: The average mesothelioma death rate was significantly higher for countries with asbestos bans than in those with no ban (4·59 versus 1·83/million). No-ban countries had less well-developed health-related infrastructures. Among European countries, there was a tendency toward geographical diffusion of asbestos ban policy from Nordic to Western and then other European countries over the years. Even though aberrant cases were also noted where bans were instituted even without mesothelioma database, these were rather exceptions than rules. Conclusion: Risk cognition is a complex process, but the presence of well-functioning health infrastructures, as well as the increased social cost of mesothelioma, that can make the plight of asbestos victims visible to the eyes of public and policy makers, may have contributed to this process. Asbestos ban policy from adjacent countries might have facilitated the adoption of alternative solutions.

Income Differences in Smoking Prevalences in 245 Districts of South Korea: Patterns by Area Deprivation and Urbanity, 2008-2014

Objectives The aim of this study was to measure income differences in smoking prevalence at the district level and to investigate correlations among area deprivation, smoking prevalence, and income differences in smoking prevalence, stratified by urbanity. Methods Data were pooled from the Community Health Survey data of South Korea between 2008 and 2014. The age-standardized prevalence of smoking and its interquintile income differences were calculated. We conducted correlation analyses to investigate the association of the deprivation index with smoking prevalence and interquintile differences in smoking prevalence. Results Across 245 districts, the median prevalence of smoking in men was 45.9% (95% confidence interval [CI], 43.4 to 48.5%), with an interquartile range (IQR) of 4.6% points. In women, the median prevalence was 3.0% (95% CI, 2.4 to 3.6%) and IQR was 1.6% points. The median interquintile difference in smoking prevalence was 7.4% points (95% CI, 1.6 to 13.2% points) in men and 2.7% points (95% CI, 0.5 to 4.9% points) in women. The correlation coefficients for the association between the deprivation index and smoking prevalence was 0.58, 0.15, -0.22 in metropolitan, urban, and rural areas, respectively, among men, and 0.54, -0.33, -0.43 among women. No meaningful correlation was found between area deprivation and interquintile difference in smoking prevalence. The correlation between smoking prevalence and interquintile difference in smoking prevalence was more evident in women than in men. Conclusions This study provides evidence of geographical variations in smoking prevalence and interquintile difference in smoking prevalence. Neither smoking prevalence nor the deprivation index was closely correlated with interquintile income difference in smoking prevalence. Measuring inequalities in smoking prevalence is crucial to developing policies aimed at reducing inequalities in smoking.

Trends in Measures of Childhood Obesity in Korea From 1998 to 2012.

Background During the last several decades, the number of children who are overweight or obese has reached alarming levels worldwide. The purpose of the present study was to examine trends in measures of childhood obesity among Korean children aged 2–19 from 1998 to 2012. Methods Height, weight, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Age-adjusted means of WC and BMI were compared between years. We used three international criteria (International Obesity Task Force [IOTF], World Health Organization [WHO], United States Centers for Disease Control and Prevention [CDC]) and a Korean national reference standard (Korea Centers for Disease Control and Prevention [KCDC]) to calculate age-standardized prevalence of childhood overweight and obesity. Results Despite differences in absolute prevalence of childhood overweight and obesity according to the four different criteria, the time trends of prevalence were generally similar across criteria. The prevalence of childhood overweight and obesity generally stabilized from 2001–2012 in both boys and girls. WC decreased from 2001–2012 in both boys and girls aged 2–19. Conclusions Further studies exploring the factors causing plateaued trends of childhood obesity measures are needed to implement effective policies for reducing the prevalence of childhood overweight and obesity.

Trends in childhood obesity and central adiposity between 1998-2001 and 2010-2012 according to household income and urbanity in Korea.

BackgroundThis study examined trends in body mass index (BMI), waist circumference (WC), and childhood overweight and obesity prevalence between 1998–2001 and 2010–2012 according to household income and urbanity among nationally representative Korean children and adolescents aged 10-19.MethodsThe repeated cross-sectional data from Korean National Health and Nutrition Examination Surveys in 1998-2001 and 2010-2012 were used. Gender specific trends in age-adjusted means of WC and BMI by household equivalized income and urbanity were compared between years. The age-standardized prevalence of childhood overweight and obesity was calculated using three international criteria (International Obesity Task Force, World Health Organization, US Centers for Disease Control and Prevention) and a Korean national reference standard.ResultsAmong boys, overall BMI and overweight prevalence increased between 1998–2001 and 2010–2012, while overall WC decreased. Clear gender differences were found in the relationship of childhood obesity metrics with household income and urbanity and the time trends of those relationships. Positive relationships between these parameters were found for boys while negative relationships appeared for girls. In addition, compared with the childhood obesity prevalence among boys in rural areas, the prevalence among boys in urban areas were slightly lower in 1998–2001 but became greater in 2010–2012.ConclusionsThis study revealed gender difference in the association of childhood obesity with household income and urbanity and its time trends. The long-term gender-specific monitoring of socioeconomic and urban-rural differences in childhood obesity measures is warranted in South Korea.

Ergonomics Job Hazard Evaluation of Building Cleaners

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.

Rising trends and inequalities in cesarean section rates in Pakistan: Evidence from Pakistan Demographic and Health Surveys, 1990-2013.

Despite global efforts to improve maternal health, many developing countries including Pakistan have failed to achieve the target of a 75% reduction in maternal deaths by 2015. Addressing socioeconomic inequalities in access to emergency obstetric care is crucial for reducing the maternal mortality rate. This study was done to examine the time trends and socioeconomic inequalities in the utilization of cesarean section (C-section) in Pakistan during 1990–2013. We used data from the Pakistan Demographic and Health Surveys (PDHS) conducted during 1990 to 2013. All these surveys are nationally representative surveys of ever-married women aged 15–49 years with a sample size of 6611, 10,023, and 13,558 women in 1990–1991, 2006–2007, and 2012–2013, respectively, with an overall response rate of over 90%. The unit of analysis for this study was women with their most recent live birth in the five years preceding the surveys. Bivariate analyses and multivariable logistic regression models were employed to investigate the prevalence of cesarean sections according to selected sociodemographic characteristics of women. C-section rates were found to have increased during this period, with an especially significant rise from 2.7% in 1990–1991 to 15.8% in 2012–2013 with lower utilization among the non-educated women (7.5%), compared with the women with higher education (40.3%). C-section rates ranged from 5.5% in the poorest women to 35.3% in the richest women. Only 11.5% of the rural women had a C-section compared to 25.6% of the urban women. A greater likelihood of having a cesarean section was observed in the richest, highly educated, and urban-living women while there was no significant difference observed in cesarean section rates between the private and public sectors in all three surveys. To improve maternal health, routine monitoring and evaluation of the provision of emergency obstetric services are needed to address the underuse of C-section in poor and rural areas and overuse in rich and urban areas.

Prevalence of Overweight and Income Gaps in 245 Districts of Korea: Comparison Using the National Health Screening Database and the Community Health Survey, 2009–2014

Background We compared age-standardized overweight prevalence and their income gaps at the level of district in Korea using the National Health Screening Database (NHSD) and the Community Health Survey (CHS). Methods We analyzed 39,093,653 subjects in the NHSD and 926,580 individuals in the CHS between 2009 and 2014. For the comparison of body mass index (BMI) distributions, data from 26,100 subjects in the Korea National Health and Nutrition Examination Survey (KNHANES) were also analyzed. We calculated the age-standardized overweight prevalence and its interquintile income gap at the district level. We examined the magnitudes of the between-period correlation for age-standardized overweight prevalence. The differences in overweight prevalence and its income gap between the NHSD and the CHS were also investigated. Results The age-adjusted mean BMI from the CHS was lower than those from the NHSD and the KNHANES. The magnitudes of the between-period correlation for overweight prevalence were greater in the NHSD compared to the CHS. We found that the district-level overweight prevalence in the NHSD were higher in all districts of Korea than in the CHS. The correlation coefficients for income gaps in overweight prevalence between the two databases were relatively low. In addition, when using the NHSD, the district-level income inequalities in overweight were clearer especially among women than the inequalities using the CHS. Conclusion The relatively large sample size for each district and measured anthropometric data in the NHSD are more likely to contribute to valid and reliable measurement of overweight inequality at the district level in Korea.