Validating the Digital Health Literacy Instrument in Relation to COVID-19 Information (COVID-DHL-K) among South Korean Undergraduates.

Digital health literacy is crucial in accessing and applying health information in the COVID-19 pandemic period. Young college students are exposed daily to digital technologies, and they have further increased the use of digital information during the COVID-19 period. This study aimed to adapt DHLI into Korean and to assess the psychometric properties, during the COVID-19 pandemic period. A cross-sectional, nationwide, and web-based survey was conducted among 604 Korean undergraduates from 23 December 2020 to 8 January 2021. On the basis of the Digital Health Literacy Instrument (DHLI) by the Global COVID HL Network, the Korean questionnaire was developed by group translation, expert reviews, and forward-backward translation for validation. The scale reliability and validity were examined using Cronbach's alpha and confirmatory factor analysis. Results support the theoretical and empirical four-factor structure (search, express, evaluate, use) in the coronavirus-related DHL among Korean University students. Internal reliability of the overall scale was high (Cronbach's α = 0.908). The four-factor model was supported by confirmatory factor analysis (GFI = 0.972, CFI = 0.984, TLI = 0.978, RMSEA = 0.045). This study revealed that the COVID-DHL-K is a valid and reliable measure with appropriate psychometric characteristics.

Who Benefits from the Fixed Copayment of Medical and Pharmaceutical Expenditure among the Korean Elderly?

The Korean National Health Insurance system imposes a 30% coinsurance for outpatient medical care and prescription drugs; however, at the age of 65, the coinsurance model changes to a copayment model that offers lower fees for the elderly. Thus, this study aimed to investigate the influence of the copayment model for outpatient visits and prescription drugs on healthcare utilization among the Korean elderly. We compared total outpatient visits, total prescriptions, and out-of-pocket expenses between a case group with copayment reduction (65 years or older) and a control group without any reduction (64 years or younger). We obtained secondary data collected from seven waves of the Korea Health Panel Survey (2010-2016). Outpatient visits increased exclusively in the case group among those with lower income. After adjusting for covariates, the results of the difference-in-differences analysis showed that, compared to the control group, there was a significant increase in outpatient visits among individuals with lower income in the case group. Our study shows that cost sharing changes affect Korean patients with different income levels in different ways.

Caregiving for Community-Dwelling Older Persons in South Korea: Current Formal and Informal Care Use and Expectation.

The aim of this study is to examine formal and informal care use among community-dwelling older Korean adults. Older adults aged between 65 and 85 (N = 516) in mid-size city, selected using the probability proportional sampling method, were interviewed in person. One third reported having at least one caregiver. Compared to respondents who did not use any informal/formal care, those who used any formal or informal care were older and were more likely to be prefrail or frail and experienced at least one hospitalization or emergency department use in the past year. Living alone or being experienced with any hospitalization was associated with formal care use. Most care recipients received informal care from families, specifically spouses. Among participants who received no formal/informal care, 19% of them expected to receive formal care support in the future. Substantial support programs for informal caregivers are needed to address the increase in demand and expectation for long-term care.

Attitudes of Korean smokers towards smoke-free public places: findings from the longitudinal ITC Korea Survey, 2005-2010.

OBJECTIVE: Prior to December 2012, restaurants in South Korea were required to implement only partial smoking bans. This study documents the changes in Korean smokers' attitudes towards smoking bans between 2005 and 2010 and explores the effects of anti-smoking advertising as a correlate of support for total smoking bans in public places. DESIGN: Longitudinal cohort study of Korean adult smokers. SETTING: The data were derived from three waves (2005, 2008 and 2010) of the International Tobacco Control (ITC) Korea Survey. PARTICIPANTS: The ITC Korea Survey respondents were a probability-based, nationally representative sample of Korean smokers aged 19 and older. The current analysis includes 995 smokers who participated in Wave 1 (2005), 1737 smokers who participated in Wave 2 (2008) and 1560 smokers who participated in Wave 3 (2010). PRIMARY AND SECONDARY OUTCOME MEASURES: Changes in respondents' awareness of secondhand smoke (SHS) harm, attitudes towards smoking bans and personal rules for smoking in private homes and/or vehicles were analysed. Correlates of support for smoking bans in public places were examined using generalised estimating equation regression models. RESULTS: More than 80% of Korean smokers are aware of the harms of SHS. The proportion of smokers who support smoke-free restaurants or smoke-free bars increased twofold between 2005 and 2010. Smokers who were aware of the dangers of SHS were more likely to support a total smoking ban in workplaces. Noticing anti-smoking advertising or information was not significantly associated with support for a total smoking ban in public places. CONCLUSIONS: Korean smokers became more supportive of smoking bans in public places between 2005 and 2008. These results show that smokers' attitudes towards smoking bans can change with the implementation of smoke-free policies, even in a country that has a high prevalence of smokers.

The impact of differential cost sharing of prescription drugs on the use of primary care clinics among patients with hypertension or diabetes.

OBJECTIVES: Since 2011, the Korean government has implemented differential cost sharing to increase the utilization of primary care clinics for the management of chronic diseases. The objective of this study was to examine the impact of the prescription drug cost-sharing increase on outpatients' selection of the medical care institution. STUDY DESIGN: This was a pre-post comparison study. METHODS: Participants were 34,842 patients with hypertension and 13,886 patients with type 2 diabetes, who were all newly prescribed. Data were collected via national health insurance system claims. The change in the main medical care institution for disease management before and after the cost sharing policy was analyzed using logistic regression analysis. RESULTS: Nearly 18% of participants with hypertension and 22% of participants with diabetes used tertiary care or general hospital outpatient services before the policy was implemented. After the increased prescription drug coinsurance rate (by 10-20%), the likelihood of selecting primary care clinics or small hospitals was significantly higher among patients with hypertension within 1 year (odds ratio [95% confidence interval] = 1.29 [1.19-1.41]) than before. However, the policy effect was not significant among patients with diabetes. CONCLUSIONS: The cost sharing policy was effective in inducing patients with hypertension to manage their chronic disease in primary care institutions; however, this was not true for patients with diabetes. The assurance of high-quality disease management services and low out-of-pocket expenses may be needed to encourage patients with chronic diseases to use primary care clinics.

Weight control behaviors according to body weight status and accuracy of weight perceptions among Korean women: a nationwide population-based survey.

This study aimed to identify associations among self-perceived weight status, accuracy of weight perceptions, and weight control behaviors, including both healthy and unhealthy behaviors, in a large, nationally representative sample from an East Asian country. Data were collected from the 2016 Korean Study of Women's Health Related Issues, a population-based, nationwide survey. Accurate weight perceptions were investigated by comparing body mass index (BMI) categories, based on self-reported height and weight, and weight perceptions. Weight control behaviors over the previous 12 months were additionally surveyed. Odds ratios (ORs) and 95% confidence intervals (CIs) are presented as an index of associations. Among normal weight, overweight, and obese women, 12.8%, 44.3%, and 17.4% under-assessed their weight; 17.9% of normal weight women over-assessed their weight. Both weight status according to BMI category and weight perceptions were strongly associated with having tried to lose weight. Exercise and diet (ate less) were the most commonly applied weight control behaviors. Misperception of weight was related to more unhealthy weight control behaviors and less healthy behaviors: Women who under-assessed their weight showed a lower tendency to engage in dieting (OR = 0.57, 95% CI = 0.43-0.75) and a greater tendency to fast/skip meals (OR = 1.47, 95% CI = 1.07-1.99). Meanwhile, normal weight or overweight women who over-assessed their weight were more likely to have engaged in fasting/skipping meals or using diet pills (OR = 5.72, 95% CI = 2.45-13.56 for fasting/skipping meal in overweight women; OR = 1.62, 95% CI = 1.15-2.29 and OR = 3.16, 95% CI = 1.15-8.23 for using diet pills in normal and overweight women). Inaccuracy of weight perceptions in any direction (over/under) were related to more unhealthy weight control behaviors and less healthy weight control behaviors, especially in normal and overweight women.

Association between intimate partner violence and mental health among Korean married women.

OBJECTIVES: Intimate partner violence (IPV) has only attracted limited attention in Korea despite numerous studies in Western countries that indicate IPV is associated with depressive symptoms. This study examined the association of IPV with depressive symptoms and suicidal ideation as moderated by the perceived gender roles of married women in South Korea. STUDY DESIGN: We analyzed a data set of 4659 married females from the 8th wave of the Korea Welfare Panel Study. Participants were categorized into three groups of non-IPV, non-physical IPV, and physical IPV. The presence of depressive symptoms and suicidal ideation was then used to predict mental health outcomes. METHODS: Logistic regression helped to investigate the association of IPV and mental health. Furthermore, an interactive regression of IPV and perceived gender roles was also done. RESULTS: Each type of IPV (non-physical and physical) was significantly associated with depressive symptoms (Odds ratios [ORs]: 1.65 and 4.34; 95% confidence interval [CIs]: 1.28-2.13 and 2.71-7.28, respectively) and suicidal ideation (ORs: 1.40 and 3.84; 95% CIs: 1.06-1.85 and 2.32-6.36, respectively) after adjusting for covariates. In addition, women who experienced IPV and reported having traditional gender roles were also more likely to report depressive symptoms (OR: 4.59; 95% CI: 2.90-7.28) and suicidal ideation (OR: 7.28; 95% CI: 3.56-14.87). CONCLUSIONS: Research findings indicate an increasingly marked pattern of work-family conflict in regard to the relationship between traditional gender roles and the effect of IPV on the mental health of women. Policy efforts are needed to reduce IPV as a mental health risk factor and address paternalistic traditions deeply rooted in Korean society that place women in an inferior family status.

Development of a transformation model to derive general population-based utility: Mapping the pruritus-visual analog scale (VAS) to the EQ-5D utility.

RATIONALE, AIMS, AND OBJECTIVES: Although nonpreference-based disease-specific measures are widely used in clinical studies, they cannot generate utilities for economic evaluation. A solution to this problem is to estimate utilities from disease-specific instruments using the mapping function. This study aimed to develop a transformation model for mapping the pruritus-visual analog scale (VAS) to the EuroQol 5-Dimension 3-Level (EQ-5D-3L) utility index in pruritus. METHODS: A cross-sectional survey was conducted with a sample (n = 268) drawn from the general population of South Korea. Data were randomly divided into 2 groups, one for estimating and the other for validating mapping models. To select the best model, we developed and compared 3 separate models using demographic information and the pruritus-VAS as independent variables. The predictive performance was assessed using the mean absolute deviation and root mean square error in a separate dataset. RESULTS: Among the 3 models, model 2 using age, age squared, sex, and the pruritus-VAS as independent variables had the best performance based on the goodness of fit and model simplicity, with a log likelihood of 187.13. The 3 models had similar precision errors based on mean absolute deviation and root mean square error in the validation dataset. No statistically significant difference was observed between the mean observed and predicted values in all models. CONCLUSIONS: In conclusion, model 2 was chosen as the preferred mapping model. Outcomes measured as the pruritus-VAS can be transformed into the EQ-5D-3L utility index using this mapping model, which makes an economic evaluation possible when only pruritus-VAS data are available.

Oral Bisphosphonates and Upper Gastrointestinal Cancer Risks in Asians with Osteoporosis: A Nested Case-Control Study Using National Retrospective Cohort Sample Data from Korea.

BACKGROUND: Bisphosphonate can irritate the gastrointestinal mucosa and increase the risk of esophageal or gastric cancer. The relatively high prevalence of upper gastrointestinal cancers and the widespread use of bisphosphonate in Korea call for further investigation. We conducted a case-control study to evaluate the risk of esophageal or gastric cancer after exposure to oral bisphosphonates in Korean patients with osteoporosis. METHODS: We used the National Health Insurance Service-National Sample Cohort database of Korea from 2002 to 2013. Among osteoporotic patients (>40 years), cases were defined as incident diagnosis of esophageal or gastric cancer between 2006 and 2013. For each case, four controls were matched for age, sex, and income level by type of insurance. We categorized bisphosphonate use as non-user, recent user, past user, and past and recent user, depending on prescription in two periods (1 to 2 years and 2 to 4 years prior to the index date). We also assessed the duration of bisphosphonate use by measuring cumulative duration of exposure (CDE). To examine the association between oral bisphosphonates and esophageal or gastric cancer, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis, adjusting for concomitant diseases. RESULTS: A total of 1,708 cases and 6,832 controls were identified. The aORs (95% CIs) of recent, past, and continuous bisphosphonate use compared to non-users were 1.18 (0.93-1.51), 1.04 (0.83-1.29), and 1.25 (0.95-1.58)), respectively. In addition, no significant association was observed by CDE, even when different outcome definitions were applied. CONCLUSIONS: This study did not prove an increased risk of esophageal or gastric cancer risk associated with bisphosphonate use, with respect to both risk windows and duration of exposure, in an Asian population-based, real-world setting.

What cigarette price is required for smokers to attempt to quit smoking? Findings from the ITC Korea Waves 2 and 3 Survey.

OBJECTIVES: We assess the cigarette price that would motivate smokers to quit. We also explore the factors associated with the required price, including exposures to non-tax tobacco control policies. METHODS: Cross-sectional analysis was conducted on data from 1257 male smokers, who participated in either Wave 2 or 3 of the ITC Korea Survey. Information was obtained on what cigarette price per pack would make them try to quit ('price to quit'). Tobit regression on log-transformed price and logistic regression on non-quitting were conducted to identify associated factors. RESULTS: The median price to quit was KRW5854 (US$5.31)/pack, given the current price of KRW2500 (US$2.27)/pack. Younger age, higher education, lack of concern about the health effects of smoking, lack of quit attempts and more cigarettes consumed per day were related to a higher price needed for a quit attempt. Exposures to combinations of non-tax policies were significantly associated with lower price levels to be motivated to quit. CONCLUSIONS: Considering the large price increase required for quit attempts, tax policy needs to be combined with other policies, particularly for certain groups, such as heavy smokers. Strengthening non-tax policies is likely to facilitate greater responsiveness to tax policy.

Living arrangements, chronic diseases, and prescription drug expenditures among Korean elderly: vulnerability to potential medication underuse.

BACKGROUND: Insufficient social security combined with family structure changes has resulted in a poverty of the elderly. The objective of this study was to examine an association of living arrangements of the elderly with chronic disease prevalence and prescription drug use. METHODS: 2008 Korea Health Panel Survey (KHPS) data were used in this study. Information on living arrangements, socio-demographics, health behaviors, chronic disease prevalence and healthcare expenditures including out-of-pocket (OOP) prescription drug expenditures for elderly aged 65 or older were collected from self-reported diaries and receipts. OOP prescription drug expenditure as a total cost that subject paid to a pharmacy for prescription drugs was examined. Logistic regression was used to identify differences in major chronic disease prevalence by living arrangements. The association of living arrangements with prescription drug use was analyzed using generalized linear model with a log link and a gamma variance distribution. RESULTS: Proportions of elderly living alone, elderly living with a spouse only, and elderly living with adults aged 20-64 were 14.5%, 48.3%, and 37.2%, respectively. Elderly living alone showed 2.43 odds ratio (OR) (95% confidence interval (CI) = 1.66-3.56) for having major chronic diseases prevalence compared to elderly living with adults. Despite a higher major chronic disease prevalence, elderly living alone showed lower OOP prescription drug expenditures (Cost Ratio = 0.80, 95% CI = 0.67-0.97) after adjusting for the number of major chronic diseases. Total OOP prescription drug expenditures were significantly lower in patients with a low income level versus high income level. CONCLUSIONS: Even though elderly living alone had a higher risk of chronic disease, they spent less on OOP prescription drug expenditures. Optimal drug use is important for elderly with chronic diseases to achieve good health outcomes and quality of life. Public health policies should be supplemented to optimize medical treatment for vulnerable elderly living alone.

The utility score of epilepsy with partial seizure measured by TTO, VAS, and EQ-5D in the general Korean population.

PURPOSES: This study aimed to measure utilities, which are quantitative terms incorporating preferences, for various health states of epilepsy with partial seizure in the general population in South Korea. It also aimed to find socio-demographic characteristics associated with the utility scores. METHODS: Utility scores using Time Trade-Off (TTO), Visual Analog Scale (VAS), and EuroQol five Dimension (EQ-5D) were obtained from 300 people aged 16 and over by face-to-face interviews. We measured utilities for three hypothetical health states of epilepsy for which scenarios were defined based on the frequency of partial seizure: seizure-free, seizure reduction, and withdrawal. We compared utilities with varying seizure frequency using a repeated-measures ANOVA, and analyzed the association between utilities and socio-demographic characteristics using a generalized estimating equation (GEE). RESULTS: The mean utility scores for withdrawal state, seizure reduction state, and seizure-free state were 0.303, 0.493, and 0.899, respectively, when measured by TTO. VAS yielded the mean utility scores of 0.211, 0.424, and 0.752 for respective health states, and corresponding scores with EQ-5D were 0.261, 0.645, and 0.959. The utility scores for the three health states were statistically different in TTO, VAS, and EQ-5D. The withdrawal state had the lowest utility scores. There were differences in mean utilities for the three health states across the three methods. Utilities by EQ-5D tended to have higher values than those by TTO and VAS. Utilities by VAS had the lowest values. In GEE analysis, the severity of epilepsy and household income were significantly related to utility scores. CONCLUSION: The withdrawal state of epilepsy had the lowest utility value and the seizure-free state had the highest by all three techniques of utility measurement used. There were significant differences in utilities between one severity level of epilepsy and another. Utility was associated with household income and the severity of disease. Utility scores for distinct epilepsy states obtained in this study could facilitate health economic analyses of epilepsy treatments and thus help decision making in resource allocation.

Poor health in the Korean older population: age effect or adverse socioeconomic position.

The objective of this study was to examine the impact of socioeconomic status and age on poor health among elderly people. Data were taken from the 2006 baseline survey of the Korean Longitudinal Study of Aging (KLoSA). We compared self-rated poor health, depressive symptoms, chronic disease, and disability in middle-aged (age 45-64), old (age 65-74), and very old (age 75-105) individuals. Logistic regression models were used to assess the effect of a poor social environment on health. Elderly Koreans generally had poor socioeconomic status and reported a high prevalence of poor health compared with middle-aged people. Respondents aged 65-74 years old and those aged 75+ were approximately three and four times more likely, respectively, to report self-rated poor health than middle-aged people. These differences were reduced by 41-71% after controlling for education, employment, and income. Elderly persons were also more likely to report depression, chronic disease, or disability, and the differences between age groups were reduced after adjustment for socioeconomic status, but to a lesser extent than was self-rated poor health. Our results indicate that a substantial portion of the gap in health status between middle-aged and older Koreans may be accounted for by the typically low socioeconomic status of elderly people. Income security and health-related interventions are required to improve the health of the elderly cohort who are confronted with the synergistic effects of aging and low socioeconomic status on health.

Area deprivation, individual socioeconomic position and smoking among women in South Korea.

BACKGROUND: The objective of this study was to examine how area deprivation and individual socioeconomic position affect smoking among women using national survey data. METHODS: Smoking and individual sociodemographic characteristics were gathered from the Third Korea National Health and Nutrition Examination Survey, 2005. The Carstairs index was derived for each area using the 2005 census data. The data were analysed using multilevel logistic regression models. RESULTS: After adjusting for age and marital status, low education and manual jobs were significantly associated with a higher likelihood of smoking. In addition, the effect of manual jobs on smoking was modified by area deprivation. When individual occupation and area deprivation were examined together, results indicated that women with manual occupation had much greater odds of smoking when they lived in the least-deprived areas (OR, 4.03; CI, 2.00 to 8.14) than did women with manual job who lived in the middle- or most-deprived areas (OR, 2.19; CI, 1.15 to 4.16), compared to the reference group (housewives in the middle- or most-deprived areas). CONCLUSION: The results of the present study show that among Korean women, manual work is associated with smoking, and the association is strongest among those living in the least-deprived areas. This interaction between manual work and area deprivation resulted in a higher smoking prevalence among women in affluent urban areas.

[Assessment of applicability of standardized rates for health state comparison among areas: 2008 Community Health Survey].

OBJECTIVES: This study shows the issues that should be considered when applying standardized rates using Community Health Survey(CHS) data. METHODS: We analyzed 2008 CHS data. In order to obtain the reliability of standardized rates, we calculated z-score and rank correlation coefficients between direct standardized rate and indirect standardized rate for 31 major indices. Especially, we assessed the change of correlations according to population composition (age and sex), and characteristics of the index. We used Mantel-Haenszel chi-square to quantify the difference of population composition. RESULTS: Among 31 major indices, 29 indices' z-score and rank correlation coefficients were over 0.9. However, regions with larger differences in population composition showed lower reliability. Low reliability was also observed for the indices specific to subgroups with small denominator such as 'permanent lesion from stroke', and the index with large regional variations in age-related differences such as 'obtaining health examinations'. CONCLUSIONS: Standardized rates may have low reliability, if comparison is made between areas with extremely large differences in population composition, or for indicies with large regional variations in age-related differences. Therefore, the special features of standardized rates should be considered when health state are compared among areas.

Effect of Cimetidine and Phenobarbital on metabolite kinetics of Omeprazole in rats.

Omeprazole (OMP) is a proton pump inhibitor used as an oral treatment for acid-related gastrointestinal disorders. In the liver, it is primarily metabolized by cytochrome P-450 (CYP450) isoenzymes such as CYP2C19 and CYP3A4. 5-Hyroxyomeprazole (5-OHOMP) and omeprazole sulfone (OMP-SFN) are the two major metabolites of OMP in human. Cimetidine (CMT) inhibits the breakdown of drugs metabolized by CYP450 and reduces the clearance of coadministered drug resulted from both the CMT binding to CYP450 and the decreased hepatic blood flow due to CMT. Phenobarbital (PB) induces drug metabolism in laboratory animals and human. PB induction mainly involves mammalian CYP forms in gene families 2B and 3A. PB has been widely used as a prototype inducer for biochemical investigations of drug metabolism and the enzymes catalyzing this metabolism, as well as for genetic, pharmacological, and toxicological investigations. In order to investigate the influence of CMT and PB on the metabolite kinetics of OMP, we intravenously administered OMP (30 mg/kg) to rats intraperitoneally pretreated with normal saline (5 mL/kg), CMT (100 mg/kg) or PB (75 mg/kg) once a day for four days, and compared the pharmacokinetic parameters of OMP. The systemic clearance (CLt) of OMP was significantly (p<0.05) decreased in CMT-pretreated rats and significantly (p<0.05) increased in PB-pretreated rats. These results indicate that CMT inhibits the OMP metabolism due to both decreased hepatic blood flow and inhibited enzyme activity of CYP2C19 and 3A4 and that PB increases the OMP metabolism due to stimulation of the liver blood flow and/or bile flow, due not to induction of the enzyme activity of CYP3A4.