Kyunghee Jung-Choi

Hidden female smokers in Asia: a comparison of self-reported with cotinine-verified smoking prevalence rates in representative national data from an Asian population

Background The low smoking prevalence in Asian women may be due to under-reporting. We therefore investigated gender difference in self-reported and cotinine-verified smoking prevalence rates in Korea Methods We analysed data from 5455 individuals (2387 men and 3068 women) in the 2008 Korean National Health and Nutrition Examination Survey. A urniary cotinine concentration of 50 ng/ml was the cut-off distinguishing smokers from non-smokers. Sensitivity analysis was done using different cut-offs of 25, 75 and 100 ng/ml. Results Cotinine-verified smoking rates were 50.0% for men and 13.9% for women, or 5.3% point and 8.0% point higher in absoulte terms, respectively, than the self-reported rates for men and women. Ratios of cotinine-verified to self-reported smoking rates were 2.36 for women and 1.12 for men. Of the 1620 cotinine-verified smokers, 12.1% of men and 58.9% of women classified themselves as non-smokers. Women who live with a spouse or parents tend to under-report their smoking more than those who live alone or with others. Conclusion Since the number of self-reported female smokers was less than half of cotinine-verified smokers, current anti-smoking policies based on self-reported smoking prevalence rates in Korea should be further directed towards hidden female smokers. Also, biochemical verification needs to be considered with national tobacco surveys in Asian countries.

Socioeconomic inequalities in suicidal ideation, parasuicides, and completed suicides in South Korea

As a result of unprecedented increase in suicides over the last decade, Korea now ranks at the top of OECD countries in suicide statistics (26.1 deaths per 100,000 population in 2005). Our study sought to document socioeconomic inequalities in self-destructive behaviors including suicidal ideation, parasuicide, and completed suicide. For prevalence of suicidal ideation and parasuicide, we used four waves of data from the Korea National Health and Nutrition Examination Survey (1995, 1998, 2001, and 2005). For suicide mortality, we abstracted suicide cases from the National Death Registration records, and linked them with population denominators from the national census in 1995, 2000, and 2005. We examined variation in self-destructive behaviors according to level of educational attainment (at the individual level), as well as area-level characteristics including level of deprivation and degree of urbanicity. Age-standardized rates were calculated through direct standardization using the 2005 census population as the standard. Inequalities were measured by the relative index of inequality and the slope index of inequality. The age-standardized prevalence of suicidal ideation decreased across consecutive surveys in both genders (18.0-13.5% for men, 27.5-22.9% for women). Parasuicides similarly decreased over time. By contrast, completed suicides increased over time (20.9-42.8 per 100,000 for men and 8.9-20.9 for women). The most prominent increases in completed suicides were observed among the elderly in both genders. Lower education, rural residence, and area deprivation was each associated with higher suicide rates. Both absolute as well as relative inequalities in suicide by socioeconomic position widened over time. Our findings suggest that the current suicide epidemic in Korea has social origins. In addition to clinical approaches targeted to the prevention of suicides in high risk individuals, social policies are needed to protect disadvantaged populations at risk of self-destructive behaviors.

The contribution of material, psychosocial, and behavioral factors in explaining educational and occupational mortality inequalities in a nationally representative sample of South Koreans: Relative and absolute perspectives

The contributions of material, psychosocial, and behavioral factors in explaining socioeconomic inequalities in health have been explored in many Western studies. Most prior investigations have looked at relative abilities to explain such inequalities. In addition, little research focuses on Asian countries, despite the fact that the prevalence and socioeconomic distribution of risk factors for mortality are different there. This study examined relative and absolute abilities of material, psychosocial, and behavioral pathways to explain educational and occupational inequalities in mortality in a nationally representative sample from South Korea. The 1998 and 2001 National Health and Nutrition Examination Survey data were pooled and linked to national mortality data. Of 8366 men and women over 30 years of age, 310 died between 1999 and 2005. Nine pathway variables were examined: three material factors (income, health insurance, and car ownership status), three psychosocial factors (depression, stress, and marital status), and three behavioral factors (smoking, alcohol consumption, and physical exercise). The relative risk and relative index of inequality were used as measures of relative inequality, and risk differences and the slope index of inequality were used as measures of absolute inequality. Material factors explained a total of 29.0% of the excess in relative risk for education and 50.0% of the excess in relative risk for occupational class. Material factors explained 78.6% of the excess in absolute mortality difference for education and 41.1% for occupational class. Psychosocial factors for both education and occupational class had a relative and absolute explanatory power of less than 15%. Behavioral factors showed a relative explanatory power of about 15%, but absolute explanatory power reached 84.0% for education and 105.4% for occupational class. However, the number of deaths used to calculate the absolute explanatory power was small. Results of this study suggest that absolute socioeconomic mortality inequalities could be substantially reduced if behavioral risk factors were reduced in the whole population.

Explaining age-specific inequalities in mortality from all causes, cardiovascular disease and ischaemic heart disease among South Korean male public servants: relative and absolute perspectives

Objective: To examine age-specific patterns in the ability of major cardiovascular risk factors to explain relative and absolute socioeconomic inequalities in mortality from all causes, cardiovascular disease (CVD), and ischaemic heart disease (IHD). Design: Prospective cohort study. Setting: South Korea. Subjects: 575 377 male public servants aged 30–64 with 16 998 deaths between 1995 and 2003. Main outcomes: All-cause, CVD, and IHD mortality. Results: Four cardiovascular risk factors (cigarette smoking, blood pressure, fasting serum glucose, and serum total cholesterol) were significantly associated with mortality risk. Changing relationships in socioeconomic distribution of risk factors with age were observed. The magnitude of reduction in percent change in absolute risk was greater than that in relative risk. While the risk factors explained only 15.2% of excess RR for all-cause mortality in low-income men aged 30–44, the absolute excess risk of all-cause mortality was reduced by 48.3% when the risk factors were removed from the whole population. This pattern was generally true for all causes, CVD, and IHD, and true for all age groups and risk factors examined. Cigarette smoking and hypertension were the leading contributors in explaining relative and absolute inequality in mortality. Conclusion: Policy efforts to eliminate major cardiovascular risk factors in the general population may have a significant effect on reducing the absolute burden of socioeconomic inequality in mortality. Policy efforts to attenuate socioeconomic inequality in cardiovascular risk factors need to be directed to younger age groups in South Korea.

The impact of governmental antismoking policy on socioeconomic disparities in cigarette smoking in South Korea.

INTRODUCTION With enactment of the 1995 Health Promotion Act, the Korean government has developed numerous antismoking policies, including smoke-free buildings and zones, a public media campaign, and tobacco taxation. The present study examined whether governmental antismoking policy during the past decade was associated with reduced socioeconomic differentials in cigarette smoking in South Korea. METHODS Data from 99,980 men and 105,193 women aged 25-64 years were analyzed from four rounds of Social Statistical Surveys of Korea between 1995 and 2006. Socioeconomic position (SEP) indicators were education, occupational class, employment status, and household income. Age-adjusted prevalence of smoking was calculated. Prevalence ratios and the relative index of inequality (RII) were estimated using log-binomial regression analysis. RESULTS Absolute socioeconomic differentials in age-adjusted prevalence of smoking increased between 1995 and 2006. Increases were found in both men and women. Prevalence ratios and RIIs also showed widening relative inequalities in smoking in all four SEP indicators in men. For women, increases in RIIs for education and income were statistically significant. The magnitude of change in prevalence ratios and RIIs by SEP indicators between 1999 and 2003 was statistically significant, whereas the difference between 2003 and 2006 was not. DISCUSSION Despite reducing overall cigarette smoking rates in males, the governmental antismoking policies of South Korea did not reduce socioeconomic inequalities in smoking in both genders. However, the recent tobacco taxation policy is likely to dampen the ever-increasing trends in smoking inequalities. More progressive antismoking policies to reduce socioeconomic inequalities in smoking are warranted in South Korea.

Relationship between prolonged standing and symptoms of varicose veins and nocturnal leg cramps among women and men

The relationships between occupational characteristics and symptoms of varicose veins and nocturnal leg cramps and their gender differences were explored in a Korean population. The study population was 2165 workers from various occupations (55.6% female). Multiple logistic regression analyses were conducted to reveal factors related to symptoms of varicose veins and nocturnal leg cramps. The prevalence of varicose veins and nocturnal leg cramps was higher among women than men. The characteristics of standing work were different according to gender. In gender stratified analysis, the odds ratio of varicose veins was significantly high for prolonged standing for male and female workers. However, the odds ratio of nocturnal leg cramps was only significant among prolonged standing male workers. The models including gender, prolonged standing and occupations in this order presented that gender is not significantly associated with varicose veins after occupations were added to the model. Prolonged standing at work may be a more important risk factor for varicose veins and nocturnal leg cramps than biological differences between women and men. Therefore, effective interventions to interrupt or reduce prolonged standing at work should be implemented for the prevention of varicose veins and nocturnal leg cramps. Practitioner Summary: This paper shows associations between occupational characteristics and symptoms of varicose veins and nocturnal leg cramps and their gender differences. These findings will contribute to knowledge of gender-specific occupational risk factors for symptoms in the distal lower extremities.

Socioeconomic differentials in cause-specific mortality among 1.4 million South Korean public servants and their dependents

Background A growing number of investigations have explored the contribution of cause of death to socioeconomic inequalities in mortality in Europe and North America, but few such studies have been performed on Asian populations. Objectives To analyse the socioeconomic inequality of cause-specific death rates from both an absolute and relative perspective, and to evaluate the contribution of cause of death to total mortality inequality in South Korea. Methods Data were obtained from public servant health insurance beneficiary records. 1 403 297 subjects aged 35–64 years were followed for 9 years. Health insurance premium levels were used as a socioeconomic position indicator. The outcome variables were all-cause, 11 broad causes and 41 specific causes of death. Mortality differentials were examined using cause-specific age-adjusted mortality, relative indices of inequality, and slope inequality indices. Results Graded inverse associations between income and mortality were found for most, but not all, specific causes of death. The major contributors to income differentials in total mortality in men were liver disease (15.4%), stroke (12.8%), land transport accidents (10.0%), lung cancer (7.1%) and liver cancer (7.0%). In women, stroke (30.7%), diabetes (9.1%), land transport accidents (6.6%), liver cancer (6.0%) and liver disease (5.1%) were important. Conclusions The contribution of the cause of death to socioeconomic inequality in mortality in South Korea differed from Western countries. To develop a policy to reduce the magnitude of socioeconomic inequality, an understanding of the major causes of death that contribute to mortality inequality is required.

Body Weight at Birth and at Age Three and Respiratory Illness in Preschool Children

OBJECTIVES The purpose of this study was to examine the associations of current body weight and body mass index (BMI) at age three and birth weight in developing chronic respiratory illness in childhood and identify possible interaction underlying its mechanism. METHODS The study was carried out with 422 children who were enrolled in a hospital-based birth cohort. Birth related anthropometric data were collected at birth. At age 3 years, the presence of respiratory symptoms was evaluated by using the Korean version of core questionnaire for wheezing and asthma from the International Study of Asthma and Allergies in Childhood (ISAAC). Physical examination was carried out to measure the childs weight and height. RESULTS Children in the lowest birth weight tertile (aOR = 3.97, 95% CI = 0.94-16.68) or highest BMI tertile (aOR = 3.68, 95% CI = 1.24-10.95) at three years of age were at an increased risk of chronic respiratory illness. Children who were initially in the lowest birth weight tertile but now belong in the highest weight tertile had higher risk of chronic respiratory illness compared to those who had remained in the middle tertile (OR=16.35, 95% CI=1.66-160.57). CONCLUSIONS Children with lower birth weight or higher BMI were at an increased risk of chronic respiratory illness. In addition, children who were initially in the lowest birth weight tertile but are now in the highest weight tertile had higher risk of chronic respiratory illness compared to those who remained in the middle tertile.

Changes in contribution of causes of death to socioeconomic mortality inequalities in Korean adults.

Objectives This study aimed to analyze long-term trends in the contribution of each cause of death to socioeconomic inequalities in all-cause mortality among Korean adults. Methods Data were collected from death certificates between 1990 and 2004 and from censuses in 1990, 1995, and 2000. Age-standardized death rates by gender were produced according to education as the socioeconomic position indicator, and the slope index of inequality was calculated to evaluate the contribution of each cause of death to socioeconomic inequalities in all-cause mortality. Results Among adults aged 25-44, accidental injuries with transport accidents, suicide, liver disease and cerebrovascular disease made relatively large contributions to socioeconomic inequalities in all-cause mortality, while, among adults aged 45-64, liver disease, cerebrovascular disease, transport accidents, liver cancer, and lung cancer did so. Ischemic heart disease, a very important contributor to socioeconomic mortality inequality in North America and Western Europe, showed a very low contribution (less than 3%) in both genders of Koreans. Conclusions Considering the contributions of different causes of death to absolute mortality inequalities, establishing effective strategies to reduce socioeconomic inequalities in mortality is warranted.

Prevention of Work-Related Musculoskeletal Disorders

Editorial Work-related musculoskeletal disorders (WMSDs) constitute a major component of occupational diseases (ODs), accounting for approximately 38.1% of all ODs in Europe [1] and approximately 70% of all compensated ODs in Korea [2]. According to a recent European Union report, WMSDs tend to be underreported and are tending to increase among women, young, and migrant workers. The costs for upper extremity WMSDs alone rage from 0.5 to 3.8% of gross national product [3]. In the United States, costs for compensation, wage loss, and production loss range from 45–54 billion US dollors [4]. Research to prevent these highly costly WMSDs is being conducted in various fields including epidemiology, physiology, ergonomics, biomechanics, molegular biology, and genetics and to tackle such issues as return to work, rehabilitation, policy and compensation. One of the most important avenues of communication for these research efforts is the Intenational Conference on Prevention of Work-related Musculoskeletal Disorders (PREMUS). There are 35 active scientific committees in the International Commission on Occupational Health, and the Musculoskeletal Disorder Committee has held an international conference every 3 years under the name of PREMUS. The most recent PREMUS conference was held in Busan, Korea on July 7–11, 2013. It was the first time that PREMUS was organized outside of North America or Europe. Attending pariticipants were 290 scholars from 30 conutries all over the world, including 11 Asian countries. Among the many papers presented at the conference, 10 describing the spectrum of WMSDs research around world were chosen to public in AOEM. The study by Nur Azmar et al. shows the prevalence and psychosocial risk factors for WMSDs among Malaysian