The aim of this study was to examine the relationship between types and amount of social activity and health-related quality of life according to gender and age group. This study used data from the Community Health Survey (CHS), which was collected in 2011 and consisted of 229,226 participants aged 19 or older. A linear mixed effects model was used to evaluate the factors influencing health-related quality of life among individuals tracked in the CHS and, in particular, to analyze the associations between the amount and types of social activities participated in and the EuroQol EQ-5D assessment. We found that the average quality of life increased according to the amount of social activities individuals participated in (zero = 89.30, one = 93.28, two = 95.25, three = 96.27, four = 96.85). When people participated in one social activity, social activity was more strongly associated with EQ-5D in the elderly age group (males: 19–34 years = 0.195, 35–49 years = 0.642, 50–64 years = 1.716, ≥65 years = 4.408; females: 19–34 years = 0.170, 35–49 years = 0.502, 50–64 years = 1.411, ≥65 years = 4.180). More participation was positively associated with higher EQ-5D (one = 1.939, two = 2.377, three = 2.439, four = 2.515, p for trend < 0.0001). In females, those who participated in relationship organizations had a higher EQ-5D than those who participated in other types of social activities (Females ≥65 age group; Relationship = 4.373, Leisure = 2.620, Religion = 1.842, Charity = 1.544). There was a positive association between the increase in the number of social activities and increase in health-related quality of life, especially when evaluated in terms of type of social activities and health-related quality of life according to gender and age group.

Objective: To examine the association between the level of Internet addiction and suicidal ideation and suicide attempts in South Korean adolescents, focusing on the roles of family structure and household economic status. Methods: Data from 221 265 middle and high school students taken from the 2008–2010 Korea Youth Risk Behavior Web-based Survey were used in this study. To identify factors associated with suicidal ideation/attempts, multiple logistic regression analysis was performed. The level of Internet use was measured using the simplified Korean Internet Addiction Self-assessment Tool. Results: Compared with mild users of the Internet, high-risk users and potential-risk users were more likely to report suicidal ideation (nonuser, odds ratio [OR] 1.10, 95% confidence interval [CI] 1.05 to 1.15; potential risk, OR 1.49, 95% CI: 1.36 to 1.63; high risk OR 1.94, 95% CI 1.79 to 2.10) or attempts (nonuser, OR 1.33, 95% CI 1.25 to 1.42; potential risk, OR 1.20, 95% CI 1.04 to 1.38; high risk, OR 1.91, 95% CI 1.71 to 2.14). The nonuser group also had a slightly higher risk of suicidal ideation/attempts compared with mild users. This association appeared to vary by perceived economic status and family structure. Conclusions: Our study suggests that it is important to attend to adolescents who are at high risk for Internet addiction, especially when they do not have parents, have stepparents, or perceive their economic status as either very low or very high.

Addressing the gender gap issue is a key to the reduction of the health gap between and within nations. This study aimed to describe gender differences in SRH of populations in South Korea and the United States (U.S.). Data on 33,240 eligible participants from the KNHNES and 39,646 participants from the NHNES was included in the study. Multiple logistic regression analysis was performed to identify gender differences in SRH. SRH was rated as poor in 18.8% and 16.3% of the participants in South Korea and in the U.S. The results of this study indicated that South Korean women had a higher risk of poor SRH, differed from women in the U.S. The 20–39 age group had a higher risk for poor SRH in both South Korea and the U.S. It suggested that South Korea's traditional gender roles negatively affect women. Thus, the welfare of South Korean should be improved to reduce these between-country health gaps by applying health-related laws to differentiation of beneficiaries’ gender and age group. Se abordan las diferencias de género como clave para la reducción de la brecha de salud. Este estudio se plantea describir las diferencias de género en salud autoinformada en Corea del Sur y Estados Unidos. Un total de 33.240 participantes de los KNHNES y 39.646 de la NHNES se incluyeron en el estudio. Se realizó un análisis de regresión logística múltiple para identificar las diferencias de género en salud autoinformada. Ésta fue calificada como pobre por el 18,8% y 16,3% de los participantes en Corea del Sur y en los Estados Unidos, respectivamente. Los resultados indicaron que las mujeres de Corea del Sur tienen mayor riesgo de mala salud autoinformada, difiriendo de las mujeres estadounidenses. El grupo de edad 20-39 años tuvo un mayor riesgo de mala salud autoinformada, tanto en Corea del Sur como en Estados Unidos. Se sugiere que los roles de género tradicionales de Corea del Sur afectan negativamente a las mujeres. Por lo tanto, el bienestar de Corea del Sur debe ser mejorado para reducir estas brechas de salud entre países mediante la aplicación de leyes que tengan en cuenta el género y el grupo de edad de los beneficiarios.

Secondhand Smoking (SHS) has been suggested as a major health problem in the world and is known to cause various negative health effects that have in turn caused the deaths of almost 600,000 people per year. Evidence has suggested that SHS may have an effect on health problems and such findings have influenced the implementation of smoking-free areas. However, few studies have investigated the effects of SHS on stress which is considered major risk factor for mental health. Thus, the purpose of our study was to investigate the association between exposure to SHS and stress. We performed a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey (2007–2012). In our study, a total of 33,728 participants were included to evaluate the association between SHS exposure and stress based on smoking status. Association between SHS exposure and stress was examined using logistic regression models. A total of 12,441 participants (42.9 %) were exposed to SHS in the workplace or at home. In our study, exposure to SHS was significantly associated with higher stress compared to non-exposure, regardless of smoking status (smoker odds ratio [OR]: 1.22; ex-smoker OR: 1.25; never-smoker OR: 1.42). Our results showed that the effect of SHS on stress was greater when exposure took place both at home and in the workplace in smokers and never-smokers. Exposure to SHS in the workplace and at home is considered to be a risk factor for high stress in both smokers and never-smoker. Therefore, strict regulations banning smoke which can smoking ban reduce SHS exposure are recommended in order to improve the populations’ health.