Youngtae Cho

Comparative epidemiology of suicide in South Korea and Japan: Effects of age, gender and suicide methods

BACKGROUND Suicide is one of the leading causes of mortality in both South Korea and Japan. AIMS The study aims to compare the descriptive epidemiology of suicide over the last two decades (1985-2006) and to explore the conditions associated with the different distribution of suicides in both countries. METHODS Age-standardized suicide rates were obtained from the OECD Health Data 2009. Age-specific suicide rates for the age groups were calculated from the WHO Mortality Database. Suicide methods were identified based on ICD-10. RESULTS Through 1980-2000, Japan showed consistently higher suicide rates compared to Korea. However, from the mid-1990s, Korea showed an acute increase of suicides and finally surpassed Japan; the age-standardized suicide rate of Korea increased from 10.2 (per 100,000) in 1985 to 21.5 in 2006, while it slightly increased from 18.4 to 19.1 in Japan. The highest age-specific suicide rate was observed among Japanese men aged 45-64 years and Korean men aged over 64 years. The increase of elderly suicides among Korean women was notable. The gender ratio increased in Japan and decreased in Korea, respectively. The preferred suicide methods were hanging and pesticide poisoning in Korea and hanging in Japan. Because of the limited number of observations, hypothesis testing of specific risk factors was not possible. CONCLUSIONS Age and gender distribution of suicide rates differed considerably between the two countries. Welfare protection throughout the life course in both countries, and pesticide regulation in Korea would be helpful in reducing the burden of suicide mortality in both countries, even if the social values could not be changed in a short time.

Body Weight Perception, Unhealthy Weight Control Behaviors, and Suicidal Ideation Among Korean Adolescents

BACKGROUND This study examined the mediating function of body weight perception (BWP) in the relation between body mass index (BMI) and unhealthy weight control behaviors (UWCBs; eg, fasting, using diet pills, or laxatives), and between BMI and suicidal ideation. It also explored the correlation between exposure to multiple UWCBs and suicidal ideation among Korean adolescents. METHODS Data on BMI, BWP, UWCBs, and suicidal ideation were obtained from the 2006 Korean Youth Risk Behavior Web-based Survey, a school-based survey conducted on a nationally representative sample of students in grades 7-12 (36,463 boys and 33,433 girls). Data were analyzed using bivariate and multivariate logistic regression. RESULTS BMI was significantly associated with both UWCB and suicidal ideation among boys and girls, even after controlling for covariates. However, the significance and magnitude of the association between BMI and UWCB were considerably attenuated when BWP was added to the model. When BWP was included, the association between overweight BMI status and suicidal ideation became nonsignificant in both sexes, whereas the association between underweight BMI status and suicidal ideation remained significant among boys. Adolescent boys and girls engaging in multiple UWCBs were at greater risk for experiencing suicidal thoughts. CONCLUSIONS This study suggests that BWP represents a potential mediator between BMI and UWCB, and between BMI and suicidal ideation among both boys and girls. Thus, school programs addressing issues related to BWP should be developed and targeted at adolescents to reduce the potential risks for both UWCB and suicidal behavior.

Relationship Between Socioeconomic Variables and Obesity in Korean Adolescents

Background Despite the importance of obesity and its association with socioeconomic status, little is known about this condition in Korean adolescents. We examined the relationship between obesity in Korean adolescents and several socioeconomic variables and compared the association of obesity with conventional and subjective indicators of socioeconomic status. Methods The study comprised 60 643 Korean adolescents aged 12 to 18 years who participated in the 2007 Korea Youth Risk Behavior Web-Based Survey. The dependent variable, obesity, and the independent variables of parental education levels, family affluence scale, subjective family economic status, and subjective school achievement were collected by using a self-administered anonymous questionnaire. Data on behavioral and psychological characteristics were also collected and used as confounding factors. Multivariate logistic regression was conducted to identify associations between socioeconomic status and obesity. Results In the descriptive analysis, adolescents with low parental education, low family affluence level, low subjective family economic status, and low subjective school achievement were more likely to be obese. However, after controlling for other risk factors in multivariate analysis, only the associations with subjective family economic status and subjective school achievement remained statistically significant. Conclusions Our results provide further evidence that the prevalent pattern of obesity in Korean adolescents—i.e., the inverse relationship between obesity and socioeconomic status—is similar to that in developed countries. In addition, these findings support the hypothesis that, as compared with objective socioeconomic status, subjective social status is more closely related to obesity.

The effects of actual and perceived body weight on unhealthy weight control behaviors and depressed mood among adult women in Seoul, Korea.

OBJECTIVES This study was conducted to examine the mediating function of body weight perception (BWP) on the relationship between body mass index (BMI) and unhealthy weight control behaviors (UWCB: e.g., fasting, or taking diet pills or laxatives) and between BMI and depressed mood, and to explore the effect of distorted BWP on UWCB and depressed mood among adult women. METHODS A regionally representative sample of 8,581 women aged 20-64 years residing in Seoul, the capital of Korea, completed the 2001 Seoul Citizens Health Indicator Survey which provides self-reported information about height, weight, BWP, UWCB, depressed mood, demographic/ socioeconomic characteristics, and health-related behaviors. Data were analyzed using bivariate and multivariate logistic regression. RESULTS BMI was significantly associated both with UWCB and depressed mood, even controlling for all covariates. However, the magnitude and significance of each association was considerably attenuated when BWP was taken into account, indicating that BWP functioned, in part, as a mediator between BMI and UWCB and between BMI and depressed mood, respectively. Among the combinations of BMI and BWP, women who perceived themselves to be heavier than their actual BMIs appeared more likely to use UWCB, whereas women who had a distorted BWP, either underestimation or overestimation as compared with their BMIs, tended to be at greater risk for depressed mood than those who had an undistorted BWP. CONCLUSIONS These findings suggest that how women perceive their body weight may be an important predictor and/or mediator of UWCB and depressed mood among adult Korean women.

Review Article: Freedom to Lead a Life We Have Reason to Value? A Spotlight on Health Inequity in the Asia Pacific Region:

The Asia Pacific region is home to more than 60% of the world’s population. Life expectancy at birth differs between countries by as much as 27 years. This article suggests that asymmetric economic growth, unplanned urbanization, marked environmental change, unequal improvements in daily living conditions, and the unequal distribution and access to quality health care have contributed to health inequities in the Asia Pacific region. Contextually specific evidence and action are needed. This requires ongoing monitoring of health inequities and systematic evaluation of societal changes and their impact on health inequities. It requires better understanding of how to translate theoretical and empirical demonstrations of the social and environmental impact on health inequities into evidence-informed policies and programs, in diverse geopolitical, socioeconomic, and sociocultural contexts across the Asia Pacific region and the range of associated complex policy processes. A spotlight is needed on health inequities and their causes else the status quo will persist.

Estimating Influenza Outbreaks Using Both Search Engine Query Data and Social Media Data in South Korea.

Background As suggested as early as in 2006, logs of queries submitted to search engines seeking information could be a source for detection of emerging influenza epidemics if changes in the volume of search queries are monitored (infodemiology). However, selecting queries that are most likely to be associated with influenza epidemics is a particular challenge when it comes to generating better predictions. Objective In this study, we describe a methodological extension for detecting influenza outbreaks using search query data; we provide a new approach for query selection through the exploration of contextual information gleaned from social media data. Additionally, we evaluate whether it is possible to use these queries for monitoring and predicting influenza epidemics in South Korea. Methods Our study was based on freely available weekly influenza incidence data and query data originating from the search engine on the Korean website Daum between April 3, 2011 and April 5, 2014. To select queries related to influenza epidemics, several approaches were applied: (1) exploring influenza-related words in social media data, (2) identifying the chief concerns related to influenza, and (3) using Web query recommendations. Optimal feature selection by least absolute shrinkage and selection operator (Lasso) and support vector machine for regression (SVR) were used to construct a model predicting influenza epidemics. Results In total, 146 queries related to influenza were generated through our initial query selection approach. A considerable proportion of optimal features for final models were derived from queries with reference to the social media data. The SVR model performed well: the prediction values were highly correlated with the recent observed influenza-like illness (r=.956; P<.001) and virological incidence rate (r=.963; P<.001). Conclusions These results demonstrate the feasibility of using search queries to enhance influenza surveillance in South Korea. In addition, an approach for query selection using social media data seems ideal for supporting influenza surveillance based on search query data.

Public trauma after the Sewol Ferry disaster: the role of social media in understanding the public mood

The Sewol ferry disaster severely shocked Korean society. The objective of this study was to explore how the public mood in Korea changed following the Sewol disaster using Twitter data. Data were collected from daily Twitter posts from 1 January 2011 to 31 December 2013 and from 1 March 2014 to 30 June 2014 using natural language-processing and text-mining technologies. We investigated the emotional utterances in reaction to the disaster by analyzing the appearance of keywords, the human-made disaster-related keywords and suicide-related keywords. This disaster elicited immediate emotional reactions from the public, including anger directed at various social and political events occurring in the aftermath of the disaster. We also found that although the frequency of Twitter keywords fluctuated greatly during the month after the Sewol disaster, keywords associated with suicide were common in the general population. Policy makers should recognize that both those directly affected and the general public still suffers from the effects of this traumatic event and its aftermath. The mood changes experienced by the general population should be monitored after a disaster, and social media data can be useful for this purpose.

Social inequalities in life expectancy and mortality during the transition period of economic crisis (1993-2010) in Korea

BackgroundsThis study examines social inequalities in life expectancy and mortality during the transition period of the Korean economic crisis (1993–2010) among Korean adults aged 40 and over.MethodsData from the census and the national death file from the Statistics Korea are employed to calculate life expectancy and age-specific-death-rates (ASDR) by age, gender, and educational attainment for five years: 1993, 1995, 2000, 2005, and 2010. Absolute and relative differences in life expectancy and Age-Specific Death Rates by educational attainment were utilized as proxy measures of social inequality.ResultsClear educational gradient of life expectancy was observed at age 40 by both sexes and across five time periods (1993, 1995, 2000, 2005, and 2010). The gradient became notably worse in females between 1993 and 2010 compared to the trend in males. The educational gradient was also found for ASDR in all five years, but it was more pronounced in working age groups (40s and 50s) than in elderly groups. The relative disadvantage of ASDR among working age Korean adults, both males and females, became substantially worse over time.ConclusionsSocial inequalities in life expectancy and ASDR of the working age group across socioeconomic status over time were closely related to the widening of the social difference created by the macroeconomic crisis and the expansion of neo-liberalism in Korea.

Is Acculturation Always Adverse to Korean Immigrant Health in the United States

This study examined the association between individuals’ proportion of life spent in the United States and the health status and health behaviors among Korean immigrants aged 25 and above. The analysis is stratified by level of education to test whether a higher proportion of time spent in the United States is associated with poorer health among both less educated and highly educated Korean immigrants. California health interview survey data from 2005 to 2007 were used to estimate logistic regression models of health and health behaviour among Korean immigrants, stratified by educational attainment. The health and health behaviour of less educated Korean immigrants tended to be worse among those with a higher proportion of residence in the United States. However, more highly educated Korean immigrants tended to exhibit lower odds of being unhealthy and lower odds of poor health behavior with a higher proportion of life spent in the United States. Acculturation is not always associated with poorer immigrant health outcomes. A higher proportion of life spent in the United States tends to be associated with more favorable health and health behavior among highly educated Korean immigrants.

Policy approaches to address the social and environmental determinants of health inequity in Asia-pacific.

Asia Pacific is home to over 60% of the world’s population and the fastest growing economies. Many of the leadership in the Asia Pacific region is becoming increasingly aware that improving the conditions for health would go a long way to sustaining economic prosperity in the region, as well as improving global and local health equity. There is no biological reason why males born in Cambodia can expect to live 23 years less than males born in Japan, or why females born in Tuvalu live 23 years shorter than females in New Zealand or why non-Indigenous Australian males live 12 years longer than Indigenous men. The nature and drivers of health inequities vary greatly among different social, cultural and geo-political contexts and effective solutions must take this into account. This paper utilizes the CSDH global recommendations as a basis for looking at the actions that are taking place to address the structural drivers and conditions of daily living that affect health inequities in the Asia Pacific context. While there are signs of action and hope, substantial challenges remain for health equity in Asia Pacific. The gains that have been made to date are not equally distributed and may be unsustainable as the world encounters new economic, social and environmental challenges. Tackling health inequities is a political imperative that requires leadership, political courage, social action, a sound evidence base and progressive public policy.