To examine and quantify the risk of cognitive impairment across a variety of occupations including unpaid work in a middle-age population using the dataset of a nationally representative longitudinal survey. A total of 20,932 observations of 5865 subjects aged 45–64 were obtained from six waves of the Korean Longitudinal Study of Aging (2006–2016). A dichotomous outcome variable was constructed on the basis of the Korean Versions of the Mini-Mental State Examination scores, and occupations were grouped into 10 occupation categories, including unpaid housekeepers. Socio-demographics, lifestyle, and medical conditions were used as covariates in mixed logistic regression models. Adjusted odds ratios and predicted probabilities of cognitive impairment were computed and adjusted for a complex survey design. In longitudinal models with all studied covariates, the risk of cognitive impairment differed significantly across occupation categories, but the association of occupation with the risk of cognitive impairment was the same between genders. In terms of the predicted probability, the risk of cognitive impairment in the unpaid housekeepers’ category (11.2%, 95% confidence interval (CI): 10.4% to 11.9%) was the highest among occupation categories, being three times higher than in the professionals’ and related workers’ category (3.7%, 95% CI: 1.6% to 5.7%). Public policies based on studies of the risk of cognitive impairment across different occupations in the middle-age population should be designed so as to prevent cognitive impairment in the middle-age population as well as their older life stages, particularly targeting high-risk groups such as people engaged in unpaid domestic and care activities.

ObjectivesTo identify gender-specific associations between education and income in relation to obesity in developed countries by considering both the interaction-effect terms of the independent variables and their main-effect terms.DesignA cross-sectional study. Education and income levels were chosen as socioeconomic status indicators. Sociodemographics, lifestyles and medical conditions were used as covariates in multivariable logistic regression models. Adjusted ORs and predicted probabilities of being obese were computed and adjusted for a complex survey design.SettingData were obtained from the Fifth Korea National Health and Nutrition Examination Survey (2010–2012).ParticipantsThe sample included 7337 male and 9908 female participants aged ≥19 years.Outcome measureObesity was defined as body mass index of ≥25, according to a guideline for Asians.ResultsIn models with no interaction-effect terms of independent variables, education was significantly associated with obesity in both men and women, but income was significant only in women. However, in models with the interaction-effect terms, education was significant only in women, but income was significant only in men. The interaction effect between income and education was significant in men but not in women. Participants having the highest predicted probability of being obese over educational and income levels differed between the two types of models, and between men and women. A prediction using the models with the interaction-effect terms demonstrated that for all men, the highest level of formal education was associated with an increase in their probability of being obese by as much as 26%.ConclusionsThe well-known, negative association between socioeconomic status and obesity in developed countries may not be valid when interaction effects are included. Ignoring these effects and their gender differences may result in the targeting of wrong populations for reducing obesity prevalence and its resultant socioeconomic gradients.

BackgroundThe health benefits of marriage have been demonstrated mainly by studies on Western populations. This study aims to test whether the benefits are also valid in East Asian populations.Methodology/Principal FindingsIndividuals (n = 8,538) from China, Japan, Taiwan, and the Republic of Korea were sampled from the 2006 East Asian Social Survey. The association between self-rated health status and two marriage-related independent variables was analyzed using multivariate logistic regression models. In a two-level analysis for individuals from all countries, married individuals were more likely to report very good or good health compared to their never-married counterparts [odds ratio (OR) 1.56; 95% confidence interval (95% CI) 1.16−2.10]. However, the addition of marital satisfaction disintegrated the significant association of marriage with self-rated health. Married individuals in satisfying marriages were more likely to report very good or good health compared with never-married individuals (OR 1.85; 95% CI 1.37−2.50). In contrast, married individuals in dissatisfying marriages were as likely to report very good or good health as never-married individuals (OR 0.78; 95% CI 0.50−1.24). In a one-level analysis for each country, the importance of marital satisfaction varied greatly across countries. Unlike in other countries, in Japan, married individuals in dissatisfying marriages were about half as likely to report very good or good health as never-married individuals (OR 0.51, 95% CI 0.31−0.83), thereby showing no significant benefits from marriage with regard to self-rated health.Conclusion/SignificanceThe present study of East Asian countries suggests that marital satisfaction is of greater importance in determining self-rated health than marriage itself, and that the importance of marital satisfaction varies across countries. Further research is required to better understand the relationship between marital satisfaction and self-rated health in different socio-cultural settings, and to establish effective social policies aiming at improving public health.

BackgroundAlthough Asian societies are remarkably different from Western societies in terms of sociocultural characteristics, little is known about the gender differences in the health effects of marriage and marital satisfaction in Asian countries.Methodology/Principal FindingsUsing a randomly sampled dataset from the 2006 East Asian Social Survey comprising 8528 individuals from China, Japan, Taiwan, and South Korea, this study performs analyses using a multivariate logistic regression model to predict the probability for a man or a woman to report poor health. Our results differ quite significantly from those of most studies focusing on Western countries. Considering marital satisfaction, there may be no health benefits from marriage for a specific gender in a given country, because the health loss associated with a dissatisfied marriage usually supersedes the health benefits from marriage. Moreover, women may reap greater health benefits from marriage than men. Additionally, those most likely to report poor health are found to be married and dissatisfied men or women, rather than never-married individuals.Conclusion/SignificanceThe present study argues the need to design and carry out a gender- and country-specific social health policy approach to target individuals suffering from poor health, thereby reducing the gender differences in health status.