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Background The purpose of this study was to analyze the association between the preoperative and postoperative use of antidepressant and benzodiazepine and all-cause mortality in elderly hip fracture patients. Methods Patients who underwent surgical treatment for hip fracture over 65 years old were classified into Past-user, Current-user, and Non-users for each period according to use history for antidepressants or benzodiazepines. And, for the subgroup analysis, patients were classified by presence of past history for psychiatric medication. A multivariable-adjusted Cox proportional hazards model was used to investigate the effects of antidepressants and benzodiazepines on all-cause mortality. Results A total of 15,576 patients were included in this study. Past users of antidepressants and benzodiazepines were 5699 (36.59%) patients and 11,319 (72.67%) patients, respectively. Current users of antidepressants and benzodiazepines were 2888 (18.54%) patients and 6287 (40.36%) patients, respectively. There were no statistically significant differences in the adjusted hazard for death compared to the non-users for both the past and the current users (p > 0.05). In the subgroup analysis, there were 12,502 once-users and 3074 never-users according to psychiatric medication. Current uses of antidepressants and benzodiazepine in the once-user did not increase adjusted hazard for death compared to the non-users (p>0.05). However, current uses of antidepressants by never-users increased the adjusted hazard for death compared to the non-user (adjusted hazard ratio, 1.31; 95% CI, 1.08–1.59; p = 0.007). Conclusions No association was observed between the uses of antidepressants and benzodiazepines after hip fracture and mortality risk in elderly patients who received psychiatric medication before hip fracture. However, the use of these medications was associated with increased all-cause mortality risk in patients who had no history of psychiatric medication before hip fracture. Level of evidence III, retrospective cohort study.

Background Amidst rapid population aging, South Korea enacted the Well-dying Act, late among advanced countries, but public opinion on the act is not still clear. Against this background, this study aims to: 1) investigate factors affecting elderly individuals’ attitude toward life-sustaining treatment, and 2) examine whether attitude toward life-sustaining treatment is related to their perceived life satisfaction. Methods Data from the 2020 Survey of Living Conditions and Welfare Needs of Korean Older Persons were used. There were 9,916 participants (3,971 males; 5,945 females). We used multivariable-adjusted Poisson regression models with robust variance to examine the association between perceived life satisfaction and attitude toward life-sustaining treatment and calculate prevalence ratios (PR) and 95% confidence intervals (CI). Results After adjusting potential confounders, the probabilities that the elderly who were dissatisfied with their current life would favor life-sustaining treatment were 1.52 times (95% CI: 1.15–1.64) and 1.28 times (95% CI: 1.09–1.51) higher for men and women, respectively, than the elderly who were satisfied. In addition, attitudes in favor of life-sustaining treatment were observed prominently among the elderly with long schooling years or high household income, when they were dissatisfied with their life. Conclusions Our results suggested that for the elderly, life satisfaction is an important factor influencing how they exercise their autonomy and rights regarding dying well and receiving life-sustaining treatment. It is necessary to introduce interventions that would enhance the life satisfaction of the elderly and terminally ill patients and enable them to make their own decisions according to the values of life.

Objective: This study examined the relationship between the flexibility of work schedule arrangements and well-being among full-time workers prior to and after the coronavirus disease (COVID-19) outbreak in South Korea. Methods: Data from the fifth 2017 and sixth 2020–2021 Korean Working Conditions Survey, including a final sample of 45,137 participants (22,460 males; 22,677 females), were used. Multiple logistic regression was performed to establish the association between schedule arrangement types and the 5-item World Health Organization Well-Being Index. Results: The study found an association between flexible schedule arrangements and good well-being in 2017: “little flexibility” (odds ratio (OR), 1.33; 95% confidence interval (CI), 1.27–1.48), “moderate flexibility” (OR, 1.48; 95% CI, 1.28–1.71), and “high flexibility” (OR, 1.35; 95% CI, 1.06–1.72). During COVID-19, only workers with “high flexibility” were likely to have good well-being (OR, 1.49; 95% CI, 1.18–1.88), while the association between well-being and “low flexibility” (OR, 1.06; 95% CI, 0.96–1.17) and “moderate flexibility” types (OR, 0.66; 95% CI 0.59–0.75) decreased. This study found that flexible working hours may contribute to better well-being among full-time workers. However, the impact of the COVID-19 pandemic on working conditions and employee well-being should be addressed while setting working hours.

Background/Aims: Current evidence suggests that liver cirrhosis (LC) causes severe psychological stress and depression, which are risk factors for suicide. Although previous studies reported the association between LC and suicidal thoughts, little is known of its effect on suicidal deaths. Therefore, this study was undertaken to investigate the effect of new-onset LC on suicide.Methods: From the National Health Insurance Service-National Sample Cohort of South Korea, 5,809 incident LC patients and 11,618 risk-set controls matched by propensity score were selected for follow-up. The incidence rate of suicide was estimated using a generalized estimating equation with a Poisson distribution. Effect size was presented as a hazard ratio (HR) using Cox’s proportional hazards model.Results: The incidence rate of suicide was 143.3 cases per 100,000 person years (95% confidence interval [CI], 100.2–205.1) among the LC cohort. The LC patients were 2.37 times more likely to commit suicide compared with matched controls (HR, 2.37; 95% CI, 1.44–3.88). Increased suicide risk was evident within the first 2 years of the follow-up period (HR, 2.59; 95% CI, 1.20–5.60) and among the 18–49-year-old age group (HR, 3.72; 95% CI, 1.45–9.56).Conclusions: Our study found increased risk of suicide in patients with new onset LC, especially during the early period following diagnosis and in younger patients. To decrease this suicide risk, a regular and continuous social support system is required.

Background Studies investigating the association between migraine and dementia have reported inconsistent findings. This study aimed to evaluate whether patients with migraine have an increased risk of dementia compared to individuals without migraine. Methods We obtained data from the 2002–2019 Korean National Health Insurance Health Screening Cohort. Non-migraine controls were selected using a 1:1 risk-set matching with a time-dependent propensity score. The main outcome was the development of all-cause dementia, and the secondary outcome was the development of each cause of dementia (Alzheimer’s, vascular, mixed or other specified, and unspecified dementia). The incidence rate of dementia was calculated using Poisson regression, and the association between migraine and dementia was evaluated using Cox proportional hazards regression. Results Among 88,390 participants, 66.1% were female, and the mean baseline age was 55.3 ± 9.4 years. During the study period, dementia cases were identified in 4,800 of the 44,195 patients with migraine and 3,757 of the 44,915 matched controls. The incidence rate of dementia was 139.6 (95% confidence interval [CI], 135.7–143.5) and 107.7 (95% CI, 104.3–111.1) cases per 10,000 person-years in patients with migraine and matched controls, respectively. Patients with migraine had a 1.30 (hazard ratio [HR], 1.30; 95% CI, 1.25–1.35), 1.29 (HR, 1.29; 95% CI, 1.23–1.35), 1.35 (HR, 1.35; 95% CI, 1.19–1.54), 1.36 (HR, 1.36; 95% CI, 1.00–1.83), and 1.30 (HR, 1.30; 95% CI, 1.17–1.45) times higher risk of developing all-cause dementia, Alzheimer’s dementia, vascular dementia, mixed or other specified dementias, and unspecified dementia than their matched controls, respectively. Conclusion Our results suggest that migraine is associated with an increased risk of subsequent dementia. Further research is warranted to confirm these findings and to reveal the underlying mechanisms.

Background Parkinson’s disease (PD) is an increasingly common neurodegenerative disease in an aging society. Whether PD is associated with an increased suicide risk is unclear. Thus, we investigated the effect of new-onset PD on suicide. Methods Using the National Health Insurance Service Senior Sample Cohort of South Korea, 17,143 incident PD patients and 17,143 risk set controls, matched by propensity score, were selected for follow-up. The incidence rate of suicide and 95% confidence interval (CI) were calculated based on a generalized linear model of the Poisson distribution. Effect sizes were expressed as hazard ratios (HRs) using the Cox proportional hazards model with a robust variance estimator that incorporated clustering within matched pairs. Results The incidence rate of suicide was 206.7 cases per 100,000 person-years (95% CI, 172.8–246.9) among the PD cohort. Compared to the matched controls, patients with PD were 2.64 times (HR, 2.64; 95% CI, 1.31–5.30) more likely to commit suicide during the first 180 days of follow-up and 2.47 times (HR, 2.47; 95% CI, 1.42–4.28) within the first 365 days of follow-up. During the entire follow-up period, patients with PD were 2.26 times more likely to commit suicide than were their matched controls (HR, 2.26; 95% CI, 1.67–3.06). Conclusion Our findings indicated an increased risk of suicide in patients with new-onset PD, regardless of the period after diagnosis. Incorporating mental health care with social and environmental interventions into primary care and PD-specialized care can help reduce suicide risk in people with PD, improving suicide prevention, identification, and risk assessment.

BACKGROUND Pain and kyphotic deformity after spinal fractures can result in a decrease in a patient's physical function and quality of life. Furthermore, physical illness, such as respiratory compromise, or mental illness, including depression, may be exacerbated by a spinal fracture. Complications caused by spinal fractures and old age are risk factors for suicide, but studies on these patients are rare. QUESTIONS/PURPOSES (1) What is the incidence rate of death by suicide after a spinal fracture in patients older than 65 years? (2) How much does the risk of death by suicide increase in patients older than 65 years who have spine fractures compared with well-matched controls? (3) How does this risk change as a function of increasing time after injury? METHODS Spinal fractures in patients older than 65 years and matched controls were selected from the National Health Insurance Service-Senior cohort (NHIS-Senior) of South Korea. The NHIS-Senior consists of 558,147 people selected by 10% simple random sampling method from a total of 5.5 million people 60 and older in 2002; all people were followed through 2015. A total of 31,357 patients with spine fractures and their 62,714 matched controls remained in the study. The mean follow-up time was 4.3 ± 3.0 years (135,229 person-years) in the spine fracture group and 4.6 ± 3.0 years (290,096 person-years) in the matched control group. We matched the groups for demographic factors such as age, gender, Charlson Comorbidity Index score, medication history, medical history, preoperative disability, number of hospital admissions, as well as socioeconomic factors such as household income level, residential district, and type of national health insurance using a 1:2 risk set propensity score matching by a nearest-neighbor matching algorithm with a maximum caliber of 0.1 of the hazard components. The incidence rate of suicide and the 95% confidence interval were calculated based on a generalized linear model with a Poisson distribution. The effect size was presented as a hazard ratio (HR) using Cox's proportional hazard model with robust variance estimator that accounts for clustering within matched pairs. RESULTS The overall risk of death by suicide throughout the surveillance period, expressed as an incidence rate, was 116 per 100,000 person-years in spinal fracture (157 deaths by suicide over 135,229 person-years). Throughout the entire surveillance period, the risk of death by suicide was greater among patients with spinal fractures than it was in the control group (HR 1.8 [95% CI 1.5 to 2.2]; p < 0.01). This difference was greatest in the first 365 days after the fracture (HR 2.5 [95% CI 1.6 to 3.8]; p < 0.01) (45 deaths by suicide, incidence rate: 156 per 100,000 person-years in spinal fracture). The risk of suicide death in patients with spine fracture from 365 days to the last follow-up was also higher than that of matched controls (HR 1.6 [95% CI 1.3 to 2.1]; p < 0.01). CONCLUSIONS Considering the substantially increased risk of death by suicide in patients with spine fractures who are older than 65 years, surgeons should consider offering psychiatric evaluation and management more frequently, particularly in patients with chronic pain, functional disability, and depressive mood. Future studies should investigate the underlying causes of suicide, such as deteriorating socioeconomic support or depression, and whether early initiation of psychological support after injury can reduce the suicide rate. LEVEL OF EVIDENCE Level III, prognostic study.

Summary: Background/Objective: The purpose of this study is to analyze the effect of surgical methods on mortality and the relative risk of patients who underwent internal fixation (IF) or hemiarthroplasty (HA) after being diagnosed as a pertrochanteric fracture over 65 years old in a Korean nationwide cohort with a single insurance medical system. Methods: The Korean National Health Insurance Service-Senior cohort (NHIS-Senior, NHIS-2018-2-111) was used in this study. The eligibility criteria for incident hip fracture patients were the following: (1) first-time admission to acute care hospitals (index admission) with pertrochanteric fracture (ICD-10 S721), (2) three years of hip fracture-free period, (3) recipients of typical surgeries including IF, HA, (4) age between 65 and 99. Results: a total of 7223 patients were enrolled in the cohort. There were 1662 patients (23%) in the HA group and 5561 patients (77%) in the IF group. Mortality rates of the IF group and HA group were 13.46 and 17.94 cases per 100 person-years, respectively. In the multivariable-adjusted Cox proportional hazard model, the HA group had 1.22 times more hazard of all-cause mortality than IF group (aHR 1.22, 95% CI 1.13–1.32). In subgroup analysis, aged 65–79 and female patients showed a prominent association between surgery type and mortality (aHR 1.52, 95% CI 1.29–1.79). Conclusions: In patients with pertrochanter fracture over 65 years, 1.22-fold mortality rate was observed when HA was performed compared to that of IF, and the difference in mortality was particularly prominent within 1-year after surgery. Keywords: Hemiarthroplasty, Internal fixation, Mortality, Pertrochanter fracture, Treatment

Heavy alcohol drinking has been reported to be associated with hypertension. Moreover, when drinking alcohol, individuals may experience symptoms such as facial flushing. Therefore, this study aimed to examine the association between changes in facial flushing and hypertension across different drinking behavior patterns in South Korean adults. Data from the Korea Community Health Survey conducted in 2019 were used, and 118 129 (51 047 men and 67 082 women) participants were included. The participants were divided into five groups based on the change in facial flushing (non-drinking, non-flushing to non-flushing, flushing to flushing, non-flushing to flushing, flushing to non-flushing). The risk of hypertension in each facial flushing group was analyzed by multiple logistic regression. Men in the non-flushing to flushing group had a significantly higher association with hypertension than other groups (men: odds ratio (OR) 1.42, confidence interval (CI) 1.14-1.76). According to the level of alcohol use disorder, the non-flushing to flushing group showed a significantly increased odds of hypertension compared to all levels of drinking (men: mild drinking: OR 1.95, CI 1.40-2.71; moderate drinking: OR 2.02, CI 1.41-2.90; women: moderate drinking: OR 1.71, CI 1.16-2.52; heavy drinking: OR 1.90, CI 1.19-3.04). This study found a significant association between changes in facial flushing and hypertension among adults in South Korea. In particular, individuals who changed from non-flushing to flushing reactions had an increased association with hypertension than the other groups. Compared to people at the same drinking level, people with non-flushing to flushing reactions were highly associated with hypertension at moderate drinking level.

This study identified the acceptance of disability’s impact on self-esteem among adults with disabilities in South Korea. This is a four-year follow-up study that obtained data from the Panel Survey of Employment for Persons with Disabilities from 2017 to 2020. In total, 3329 individuals participated. Logistic regression examined the acceptance of disability’s effect on self-esteem. These variables were categorized based on the acceptance of disability (high→high, low→high, high→low, and low→low) and self-esteem (low and not low). Compared to the participants with a consistently high acceptance of disability, those with constantly low acceptance were 2.35 times (95% CI 1.81–3.04) more likely to have low self-esteem. When the acceptance of disability was low→high and high→low, the low self-esteem probability was 1.23 and 1.66 times, respectively. Low self-esteem was prominent for the following: men, 50–64-year olds, married, urban, economic activists, the mid–low household income category, and those with sensory disability. Acceptance of disability can adversely affect self-esteem when it is consistently low or changes from high to low. Among socio-economic factors, there were several risk factors that could make individuals more vulnerable to low self-esteem. Therefore, it is necessary to help people accept their disabilities to maintain healthy self-esteem levels.

OBJECTIVE : This study aimed to investigate the relationship between long working hours and chronic kidney disease (CKD) according to diabetic status. METHODS : 12,703 full-time employees without diabetes and 2,136 with diabetes were included in this study. Participants were grouped according to working hours: ≤40, 41-52, and > 52 h/week. Multiple logistic regression was used to evaluate the association between working hours and CKD prevalence. RESULTS : Participants with diabetes who worked 41-52 h/week showed 1.85 times higher odds of CKD (95% CI 1.15-2.96; P = 0.0112) compared with those who worked ≤40 h/week after adjusting for covariates. An interaction between diabetes and long working hours was observed (P for interaction = 0.0212) in the model. CONCLUSION : Long working hours are associated with CKD in participants with diabetes. An interaction between long working hours and diabetes leading to CKD development may exist.

Background The purpose of this study was to compare the mortality rate between patients undergoing hemiarthroplasty (HA) and those undergoing total hip arthroplasty (THA) in two age groups: patients aged 65–79 years (non-octogenerian) and patients aged ≥ 80 years (octogenarian). Methods We identified elderly (aged ≥ 65 years) femoral neck fracture patients who underwent primary THA or HA from January 1, 2005 to December 31, 2015 in South Korea using the Health Insurance and Review and Assessment database; the nationwide medical claim system of South Korea. We separately compared the mortality rate between the HA group and THA group in two age groups. A generalized estimating equation model with Poisson distribution and logarithmic link function was used to calculate the adjusted risk ratio (aRR) of death according to the type of surgery. Results The 3,015 HA patients and 213 THA patients in younger elderly group, and 2,989 HA patients and 96 THA patients in older elderly group were included. In the younger elderly group, the mortality rates were similar between the two groups. In older elderly group, the aRR of death in the THA group compared to the HA group was 2.16 (95% confidence interval [CI], 1.20–3.87; P = 0.010) within the in-hospital period, 3.57 (95% CI, 2.00–6.40; P < 0.001) within 30-days, and 1.96 (95% CI, 1.21–3.18; P = 0.006) within 60-days. Conclusions In patients older than 80 years, THA was associated with higher postoperative mortality compared to HA. We recommend the use of HA rather than THA in these patients., Graphical Abstract

Several studies have shown that the use of sulfonylureas in patients with type 2 diabetes mellitus (T2DM) is associated with a higher risk of hepatocellular carcinoma (HCC). In this study, we investigated the effects of individual sulfonylureas on HCC development using the National Health Insurance Service-National Sample Cohort in South Korea. Among 47,738 subjects aged 40 years or older who had newly diagnosed with diabetes, 241 incident HCC cases and 1205 matched controls were identified. Adjusted odds ratios (ORs) as estimates of the relative risk of HCC were calculated using logistic regression analysis. Compared to patients never treated with a sulfonylurea, those treated with a sulfonylurea had a 1.7-fold increased risk of HCC development. Of the different types of sulfonylureas, the exclusive use of glimepiride was associated with a significantly elevated risk of HCC (OR = 1.89, 95% CI = 1.02–3.47) compared to those who were never treated with sulfonylureas. No significant associations were observed between exclusive gliclazide use and incident HCC (OR = 2.04, 95% CI = 0.75–5.52). In conclusion, the association between the use of sulfonylureas and risk of HCC was different according to the type of sulfonylurea, in patients with new-onset T2DM. Further prospective studies are warranted to confirm these results and translate them into clinical practice.

Objective: This study aimed to explore the associations between smartphone overdependence (smartphone addiction) and suicidal ideation and attempts among Korean adolescents to acknowledge the risk of smartphone overuse. Methods: Data were obtained from the results of the 2020 Korea Youth Risk Behavior Web-based Survey. Smartphone addiction was categorized into three groups: adolescents who scored less than 23 were categorized as the general user group and formed the reference, those with scores of 23–30 were categorized as the potential-risk user group, and those with scores higher than 31 were categorized under the high-risk user group. Suicidal ideation and suicide attempt were identified as dependent variables in the present study. Multiple logistic regression was used to analyze the relationship between SA and suicidal ideation and suicide attempt status among Korean adolescents. Results: This study included 41,173 general users of smartphones, 12,142 potential-risk users, and 1633 high-risk users from among 54,948 adolescents who were middle- and high-school students. Adolescents with potentially risky smartphone use showed a higher likelihood of suicidal ideation (OR: 1.50, CI: 1.42–1.60). Similarly, adolescents with high-risk smartphone use showed a significant risk of suicidal ideation (OR: 2.49, CI: 2.21–2.81) and suicide attempt (OR: 1.87, CI: 1.48–2.37) compared to the adolescents who were general users. Conclusion: Our study results encourage parents and social workers to acknowledge that adolescents’ smartphone addiction leads to a higher risk to their mental health, wherein they may engage in suicidal ideation and even resort to a suicide attempt.

Background The purpose of study was to investigate the incidence rate of suicide in elderly patients with osteoporotic fractures in a nested case-control model and to analyze the change in the risk of suicide death over time after each osteoporotic fracture. Methods We used the National Health Insurance Service-Senior cohort of South Korea. Suicide cases and controls were matched based on sex and age at the index date. Controls were randomly selected at a 1:5 ratio from the set of individuals who were at risk of becoming a case at the time when suicide cases were selected. Conditional logistic regression analysis was performed to evaluate the association between each type of osteoporotic fracture and the risk of suicide death. Results Three thousand seventy suicide cases and 15,350 controls were identified. Patients with hip fracture showed an increased risk of suicide death within 1 year of fracture (adjusted odds ratio [aOR] = 2.64; 95% confidence interval [CI], 1.57–4.46; P < 0.001) compared to controls. However, the increased risk of suicide death in patients with hip fracture lasted up to 2 years (aOR = 1.59; 95% CI, 1.04–2.41; P = 0.031). Spine fracture increased the risk of suicide deaths for all observation periods. There was no evidence that humerus fracture increased the risk of suicide death during the observational period. Radius fracture increased only the risk of suicide death within 2 years of fracture (aOR = 1.43; 95% CI, 0.74–2.77; P = 0.282). Conclusion There were noticeable differences in both degree and duration of increased suicide risks depending on the type of osteoporotic fracture. Mental stress and suicide risk in elderly patients after osteoporotic fracture should be assessed differently depending on the types of fracture., Graphical Abstract

Background The purpose of our study was to assess the use of opioids before and after hip fracture in elderly patients in order to determine the effect of opioid use on all-cause mortality, and to analyze how the history of opioid use before fracture increases the risk of sustained use following hip fracture using a Korea nationwide cohort. Methods Our study identified hip fracture patients from the Korean National Health Insurance Service-Senior cohort. The index date was defined as 90-days after admission to the acute care hospital that fulfilled the eligibility criteria of elderly hip fracture. Patients were classified into past user, current user, and sustained user according to the use of opioid at each period based on the time of admission and index date. The opioids were classified into strong opioids and tramadol. A generalized estimating equation model with a Poisson distribution and logarithmic link function was performed to estimate the adjusted rate ratios (aRRs) and 95% confidence intervals (CIs) to assess the association between past use and sustained use. A multivariable-adjusted Cox proportional hazard model was used to investigate the effects of strong opioid and tramadol use on all-cause mortality. Results A total of 12,927 patients were included in our study. There were 7,384 (57.12%) opioid past-users, 11,467 (88.71%) opioid current-users, and 7,172 (55.48%) sustained users. In comparison of the death risk according to current use or the defined daily dose of the opioids or past opioid use, there were no significant differences in the adjusted hazard ratio for death in all groups, compared to the current non-users (P > 0.05). Among survivors 1 year after hip fracture, opioid past-use increased the risk of opioid sustained use by 1.52-fold (aRR; 95% CI, 1.45–1.8; P < 0.001). Conclusion Current use and past use of opioid did not increase all-cause mortality after hip fracture in elderly patients over 65 years of age. Past use of opioid before hip fracture increased risk of sustained use of opioid compared to the current opioid used without past use., Graphical Abstract

Background Rheumatoid arthritis (RA) has extra-articular manifestations of cardiovascular diseases and is associated with a high mortality rate in Western populations. This study aimed to investigate the risk of acute coronary syndrome (ACS) and atrial fibrillation (AF) associated with RA in a Korean population.Methods and Results:Patients were selected from a senior cohort from the Korean National Health Insurance Service in 2002, and followed until 31 December 2015. Patients with newly developed ACS and AF were identified and compared with controls for a 10-year period using time-dependent propensity and risk-set matching. A total of 4,217 incident RA patients and their 8,432 controls comprised the incident RA and matched cohorts, respectively. ACS was identified during 24,642 person-years [incidence rate (IR) 402 per 10,000 person-years, 95% confidence interval (CI) 330-489] among the RA cohort. In the matched cohort, 141 ACS patients were identified during 50,011 person-years (IR 282 per 100,000 person-years, 95% CI 239-333). RA patients were 1.43-fold more likely to develop ACS than the matched controls [hazard ratio (HR) 1.43, 95% CI 1.10-1.84], but showed similar occurrence risk of AF (HR 1.06, 95% CI 0.83-1.35). Conclusions A higher risk for ACS and a similar risk for AF were found by risk-set matched analysis in a senior RA cohort compared with the control, using Korean nationwide long-term data.

Interest in high protein diets has recently been increasing for reduction of weight or management of cardiometabolic risks. However, studies on high protein, low carbohydrate diet in Asians are limited. This study aimed to estimate whether the dietary ratio of protein (%) to carbohydrate (%) from total energy intake (p/c ratio) is associated with the risk of metabolic syndrome (MS) and its components in Korean adults using a long-term prospective cohort. A total of 6335 participants from the Korean Genome and Epidemiology Study, aged between 40 and 69 years, with no previous diagnosis of MS, cardiovascular diseases, or cancer at baseline (2001&ndash, 2002) were followed until 2013. Dietary intake was measured using a validated semiquantitative food-frequency questionnaire. MS components were measured at baseline and every 2 years. During a mean of 7.7 years of follow up, 1198 (36.1%) men and 1169 (38.8%) women developed MS. The multivariate adjusted hazard ratio (HR) of incident MS was 1.43 (95% confidence interval, 1.09&ndash, 1.89) for the highest compared lowest quintile of p/c ratio in men. When evaluating each component of MS, higher dietary p/c ratio was associated with an increased risk of high triglyceride and fasting glucose in men (HR for fifth vs. first quintile, 1.39 and 1.41 in Model 3, respectively). However, we observed no associations with incident MS and its components and dietary p/c ratio in women. In conclusion, we found that high dietary p/c ratio was associated with an increased risk of MS and its components (i.e., increased triglycerides and fasting glucose) in men. Our study suggested that even if the absolute amount of protein intake is not large, an increased p/c ratio may increase the risk of metabolic diseases.

Background The purpose of the present study was to evaluate the incidence rate (IR) of suicide in elderly patients with hip fracture on the basis of a nationwide cohort and to analyze the change in the hazard ratio for suicide after hip fracture over time in comparison with a control group. Methods Patients with hip fracture and their matched controls were selected from the National Health Insurance Service-Senior cohort (NHIS-Senior) of the Republic of Korea. The NHIS-Senior consists of 558,147 people selected by a 10% simple random-sampling method from a total of 5.5 million subjects ≥60 years of age in 2002. Risk-set matching (1:2) on the propensity score was performed with use of a nearest neighbor matching algorithm with a maximum caliper of 0.1 for the hazard components. The IR of suicide and 95% confidence interval (CI) were calculated on the basis of a generalized linear model with a Poisson distribution. The effect size was presented as a hazard ratio (HR) with use of the Cox proportional-hazard model with a robust variance estimator that accounts for clustering within matched pairs. Results A total of 11,477 patients with hip fracture and 22,954 matched controls were included. The mean duration of follow-up was 4.59 years, generating 158,139 person-years. During follow-up, a total of 170 suicides were identified. Comparisons at up to 180 days and 365 days showed that patients with hip fracture were at higher risk for suicide than matched controls (p = 0.009 and 0.004, respectively; stratified log-rank test). During the first 180 days of follow-up, 14 suicides were identified in patients with hip fracture during 11,152 person-years (IR, 266.1 per 100,000 person-years; 95% CI, 157.6 to 449.4). Patients with hip fracture were 2.97 times more likely to kill themselves than their matched controls during the same period (HR = 2.97; 95% CI, 1.32 to 6.69). Conclusions Hip fracture in elderly patients increased suicide risk within a year. A new approach to psychiatric evaluation and management is needed in elderly patients with hip fracture. Level of evidence Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

This study aimed to investigate the prevalence ofThis retrospective nationwide study identified subjects from the Korean National Health Insurance Service-Senior cohort. The subjects of this study were patients who were over 65 years old and underwent surgical treatment for hip fractures from January 1, 2002, to December 31, 2015. The total number of patients included in this study was 10,158. The diagnostic code used in this study was A047 of the International Classification of Diseases, 10th revision for identifying CDC. Procedure codes forThe prevalence of CDC during the hospitalization period in the elderly patients with hip fractures was 1.43%. Compared to the non-CDC group, the CDC group had a 2.57-fold risk of 30-day mortality after discharge, and a 1.50-fold risk of 1-year mortality after discharge (The prevalence of CDC after hip fracture surgery in elderly patients was 1.43%. CDC after hip fracture in the elderly patients significantly increased the all-cause mortality rate after discharge.

Background The purpose of this study was to analyze the all-cause mortality rate over time after elderly hip fracture in end-stage renal disease (ESRD) patients with dialysis, using a Korean nationwide claims database. Methods This retrospective nationwide study identified subjects from the Korean National Health Insurance Service-Senior cohort (NHIS-Senior). The NHIS-Senior (total of 588,147 participants) was constructed by 10% random sampling and was designed to represent the elderly living in Korea. Subjects were patients aged 65–99 years who underwent surgical treatment for femoral neck fractures or intertrochanteric fractures. A generalized estimating equation model with Poisson distribution and logarithmic link function was used to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) to measure associations between renal dialysis and cumulative mortality in various time frames. Results The total number of patients included in this study was 16,818. These patients were divided into two groups: 116 (0.69%) in the dialysis group and 16,702 (99.31%) in the no-dialysis group. The mean length of hospital stay was 43.87 ± 48.45 days in the dialysis group and 36.29 ± 37.49 days in the no-dialysis group (P = 0.095). The effect of renal dialysis on all-cause mortality was 2.29-fold (aRR; 95% CI, 1.29–4.06; P = 0.005) within 30 days and 1.72-fold (aRR; 95% CI, 1.34–2.21; P < 0.001) within 1-year after hip fracture compared to the no-dialysis group. And, the effect of renal dialysis of in-hospital mortality was 2.72-fold (aRR; 95% CI, 1.71–4.33; P < 0.001) compared to the no-dialysis group. Conclusion Elderly patients who underwent dialysis have very high mortality rates after hip fracture. Therefore, it is considered that postoperative care through multidisciplinary management and understanding of pathophysiology for the ESRD patients is necessary., Graphical Abstract

Although evidence is emerging that autoimmunity may be associated with neurodegeneration in glaucoma (beyond intraocular pressure-mediated damage), there is limited evidence connecting rheumatoid arthritis (RA), the most common autoimmune disease, with the risk of developing primary open-angle glaucoma (POAG).To investigate whether RA is associated with increased risk of POAG among Korean older adults.A nationwide propensity-matched cohort study was conducted using data from the Korean National Health Insurance Service-Senior cohort from 2002 to 2013. Data analysis was performed from November 2020 to July 2021.New onset RA.The main outcome was development of POAG. The Kaplan-Meier method was used to calculate the cumulative incidence of POAG, and the incidence rate of POAG was estimated using a Poisson regression. A Cox proportional hazards regression model was used to investigate associations between RA and risk of POAG.Among 10 245 participants, 7490 (73.1%) were women, and the mean (SD) age was 67.70 (4.84) years. A total of 2049 patients with incident seropositive RA and 8196 time-dependent, propensity score-matched, risk-set controls were included. POAG developed in 86 of 2049 patients with RA and 254 of 8196 matched controls. The cumulative incidence of POAG was higher in the RA cohort than in the matched controls. In the RA cohort, the incidence rate of POAG was 981.8 cases per 100 000 person years (95% CI, 794.3-1213.7 cases per 100 000 person years), whereas in the matched controls, the incidence rate was 679.5 cases per 100 000 person years (95% CI, 600.8-768.3 cases per 100 000 person years). Patients with RA were more likely to develop POAG than the matched controls (hazard ratio [HR], 1.44; 95% CI, 1.13-1.84). Increased POAG risk in the RA cohort was predominantly observed 2 years into the follow-up period (HR, 1.83; 95% CI, 1.28-2.61) and in those aged 75 years or older (HR, 2.12; 95% CI, 1.34-3.35).These findings suggest that RA is associated with a higher risk of developing POAG, especially within 2 years after diagnosis or among patients aged 75 years or older. There may be a common pathophysiological pathway between RA and POAG that is possibly immune mediated, and the nature of this association warrants further investigation.

Background & Aims Statins are widely used to treat hypercholesterolemia. Statins may prevent hepatocellular carcinoma (HCC), but have not yet been fully studied, particularly in patients at high risk. Therefore, we investigated the risk of HCC after statin use in the whole general population and evaluated the effects of preexisting diabetes mellitus (DM) and liver cirrhosis (LC) on that risk. Methods A nationwide, nested case-control study was conducted with data from the National Health Insurance Service Physical Health Examination Cohort 2002–2013 in the Republic of Korea. Individuals diagnosed with HCC were matched to controls based on the time of the follow-up, sex, and age at index date. Odds ratios (ORs) and 95% confidence intervals (CIs) for HCC associated with statin use were analyzed by multivariable conditional logistic regression analyses. In total, 1,642 HCC cases were matched to 8,210 control individuals from 514,866 participants. Results Statin use was associated with reduced risk of HCC development (adjusted OR [AOR] 0.44; 95% CI 0.33–0.58) compared with nonusers. The reduction in risk was significant in the presence (AOR 0.28; 95% CI 0.17–0.46) and absence of DM (AOR 0.53; 95% CI 0.39–0.73) and in the presence (AOR 0.39; 95% CI 0.26–0.60) and absence of LC (AOR 0.42; 95% CI 0.32–0.57). Statin use also significantly reduced the risk of HCC among patients with DM, without chronic complications (AOR 0.19; 95% CI 0.08–0.46) or with chronic complications (AOR 0.34; 95% CI 0.19–0.64), compared to nonusers. Conclusions Statin use may have a beneficial inhibitory effect on HCC development, particularly in patients with DM or LC, at high risk of HCC. Lay summary In this longitudinal nationwide population-based nested case-control study, the association between statin use and the risk of HCC was investigated in Asian populations. Herein, we noted a beneficial effect of statin use on the development of HCC in the general population and individuals at high risk of HCC ( i.e. those with diabetes or liver cirrhosis).

Although many studies have identified factors associated with mood disorder, the association between high-density lipoprotein cholesterol (HDL-C) and mood disorder is still controversial. The aim of our study was to evaluate the association between low HDL-C and onset of mood disorder in Korea based on different cut-off levels.We used National Health Examinations Service cohort data from 2009 to 2013. We used time-dependent Cox regression analysis to evaluate the association between low level of HDL-C and onset of mood disorder. Hazard ratios (HRs) for onset of mood disorder were estimated for 1- to 2-year time intervals, starting at the first health examination and accounting for the duration until the next health examination.A total of 400,803 participants (male: 220,573; female: 180,230) were included in our study. A total of 4576 (2.07%) males and 7598 (4.22%) females developed mood disorder. Based on dyslipidemia (40mg/dL), low level of HDL-C was associated with the risk of mood disorder in both male and female, however, only females showed statistically significant (HR: 1.097, 95% CI: 1.012-1.189). Based on quartile-based approach, females with low levels of HDL-C (47mg/dL) and males with high levels of HDL-C (≥ 59mg/dL) were associated with subsequent risk of mood disorder.Our findings suggest that level of HDL-C is associated with potential risk factors in mood disorder. However, a flexible threshold value in HDL-C level would be needed to evaluate the subsequent risk of mood disorder. Thus, further studies are needed to help improve the mental health in susceptible individuals.

Sarcopenia, or loss of muscle mass, occurs with aging and results in frailty, disability, cardiovascular disease, and insulin resistance. Recently, researchers have asserted that sarcopenia is not an inevitable process, but is a modifiable condition. Adequate sleep duration is also important to maintain good physical and mental health. Therefore, the aim of our study was to examine the association between sleep duration and sarcopenia in Korean adults.Data from 16,148 participants (7,158 men and 8,990 women) were analyzed from the 2008-2011 Korean National Health and Nutrition Examination Survey (KNHANES). We defined sarcopenia as one standard deviation below the sex-specific means of the appendicular skeletal muscle/height-squared values of a young reference group. Participants were categorized into 5 groups according to sleep duration. The odds ratios (OR) and 95% confidence intervals (95% CI) for sarcopenia according to sleep duration were calculated using multiple logistic regression analysis.The prevalence of sarcopenia was 14.3% in the total population (males 18.7%, females 9.7%). Compared to the 7 hours of sleep group, the OR (95% CI) for sarcopenia of the long sleep duration group (9 hours or more) was 1.589 (1.100-2.295) after controlling for confounding factors. From the results of subgroup analysis, high-risk groups for sarcopenia are as follows: 40-64 years old (OR = 1.868), normal body mass index (OR = 1.516), smoking (OR = 2.219), no regular exercise (OR = 1.506) in long sleepers.Long sleep duration (9 hours or longer) is independently associated with sarcopenia in Korean adults.

Background The purposes of this study were 1) to investigate the incidence of pneumonia during hospitalization in elderly hip fracture patients, 2) to evaluate the effect of pneumonia on 30 day to 1 year mortality and 3) to analyze the impact of age and gender on the mortality rate in the pneumonia patients using a nationwide cohort of Korea. Methods The Korean National Health Insurance Service (NHIS) database included approximately 5.5 million Korean enrollees > 60 years of age. A total of 588,147 participants were randomly selected for senior cohort using 10% simple random sampling. We identified senile (> 65 years old) patients who underwent hip fracture surgery from January 2005 to December 2014 and those who developed pneumonia during hospitalization from the NHIS-Senior cohort. The index date of hip fracture occurrence was defined as the date of admission to the acute care hospital. The last date of follow-up was defined as the date of death or 31 December 2015, whichever came first. A multivariable-adjusted Cox proportional hazards model was used to investigate the effects of pneumonia on all-cause mortality. Results During the enrollment period, a total of 14,736 patients, who were older than 65 years, underwent hip fracture surgeries. Among them, 1,629 patients (11.05%) developed pneumonia during the hospitalization. The pneumonia incidence was 16.39% (601/3,666) in men patients and 9.29% (1,028/10,042) in women patients. Compared to 13,107 non-pneumonia patients, adjusted relative risk (aRR) of death in pneumonia patients was 2.69 (95% confidence interval [CI], 2.14–3.38; P < 0.001) within postoperative 30-day, 3.40 (95% CI, 3.01–3.83; P < 0.001) within postoperative 90-day, 2.86 (95% CI, 2.61–3.15; P < 0.001) within postoperative 180-day and 2.31 (95% CI, 2.14–2.50; P < 0.001) within postoperative 1-year. According to patient's age, the aRR of death in pneumonia patients was 5.75 (95% CI, 2.89–11.43) in adults aged < 70 years, 5.14 (95% CI, 4.08–6.46) in those aged 70–79 years, 3.29 (95% CI, 2.81–3.86) in those aged 80–89 years and 2.02 (95% CI, 1.52–2.69) in those aged ≥ 90 years. The aRR was 3.63 (95% CI, 3.01–4.38) in men pneumonia patients, and 3.27 (95% CI, 2.80–3.83) in women pneumonia patients. Conclusion The prevalence of pneumonia in elderly hip fracture patients was 11.05%. Men had higher incidence (16.39%) than women (9.29%). Compared to non-pneumonia patients, the pneumonia patients had higher 30-day to 1-year mortalities with aRR of 2.31 to 3.40. They had increased mortality in all age groups older than 65 years with aRR of 1.52 to 4.08. Both genders of pneumonia patients had higher risk of mortality (aRR, 3.63 in men and 3.27 in women) compared to non-pneumonia patients., Graphical Abstract

Background The voluntary diagnosis-related group (DRG) payment system was introduced in 2002. Since July 2013, the Korean government has mandated DRG participation for all hospitals. The main purpose of this study was to examine the effects of mandatory DRG participation on various outcome metrics for appendectomy patients. Materials and methods We collected inpatient DRG data for 280,062 appendectomy patients between 2007 and 2014 using the Health Insurance Review and Assessment database. We examined patient outcome metrics such as length of stay (LOS), total medical cost, spillover, and readmission rate, according to hospital size. Results As a result of DRG participation, the average LOS for patients decreased (adjusted ratio: 0.83 [large hospitals], 0.83 [small hospitals]; 95% confidence interval [CI]: 0.82-0.84, 0.82-0.84), the total medical costs of patients increased (adjusted ratio: 1.23 [large hospitals], 1.35 [small hospitals]; 95% CI: 1.22-1.24, 1.34-1.36), the spillover of patients increased (adjusted ratio: 2.10 [large hospitals], 2.30 [small hospitals]; 95% CI: 2.03-2.18, 2.16-2.45), and the readmission rates of appendectomy patients decreased (adjusted ratio: 0.85 [large hospitals], 0.49 [small hospitals]; 95% CI: 0.77-0.94, 0.42-0.57). Conclusions The mandatory implementation of the DRG payment system in South Korea has led to significant reductions in LOS and readmission rates for appendectomy patients. However, any resulting expansion of outpatient services may result in unnecessary resource usage rather than improving medical quality. Policy makers should consider the various implications reflected by these results when considering DRGs for other diseases.

Introduction Suicide is a leading cause of death globally and is one of the most exigent health problems, especially in Korea. Individuals think about suicide first before they attempt and possibly complete suicide. If attempted or completed suicide affects suicidal ideation by family members or close individuals, suicide could spread like an infectious disease. We hypothesized that a suicide attempt by a family member could affect suicidal ideation. We analyzed the association between suicidal ideation and previous suicide attempts by family members. Methods This study used data from the fourth and fifth Korea National Health and Nutrition Examination Survey (2007–2012). The independent variable of interest is the existence of a cohabitating family member who previously attempted suicide. The dependent variable is self-reported suicide ideation during past year. The data analysis was conducted using the chi-square test and survey logistic regression. Results Suicidal ideation was reported by 14.3% of the total study population (9.5% of males, 19.0% of females), by 23.6% (22.8% of males, 31.3% of females) of individuals with a family member who attempted suicide, and by 14.1% (9.3% of males, 19.9% of females) of individuals without a family member who attempted suicide. Individuals with a family member who attempted suicide had increased odds of suicidal ideation compared with those without a family member who attempted suicide (odds ratio = 2.09, 95% CI 1.48–2.49, p Conclusions To prevent suicide spreading like an infectious disease, government and policy makers should give thought and consideration to individuals with a family member who attempts suicide.

Concerns have been raised about the loss of treatment continuity in unipolar and bipolar depressive disorder patients as continuity of care (COC) may be associated with patient outcomes. This study aimed to examine the relationship between COC and subsequent hospitalization, all-cause mortality, and suicide mortality in individuals with unipolar and bipolar disorder. Data were from the National Health Insurance (NHI) cohort, 2002 to 2013. Study participants included individuals first diagnosed with unipolar depressive disorder or bipolar affective disorder. The independent variable was COC for the first year of outpatient visits after diagnosis, measured using the usual provider of care (UPC) index. The dependent variables were hospitalization in the year after COC measurement, all-cause mortality, and suicide mortality. Analysis was conducted using logistic regression and Cox proportional hazards survival regression. A total of 48,558 individuals were analyzed for hospitalization and 48,947 for all-cause and suicide mortality. Compared to the low COC group, the medium [odds ratio (OR) 0.30, 95 percent confidence interval (95% CI) 0.19-0.47] and the high COC group (OR 0.14, 95% CI 0.09-0.21) showed statistically significant decreased odds of hospitalization. Additionally, lower likelihoods of suicide death were found in the high (HR 0.35, 95% CI 0.16-0.74) compared to the low COC group. The results infer an association between COC after first diagnosis of unipolar or bipolar depressive disorder and hospitalization and suicide mortality, suggesting the potential importance of treatment continuity in improving patient outcomes.

Purpose A soft tissue sarcoma (STS) is a rare type of cancer, accounting for 1% of adult solid cancers. The aim of the present study is to determine the incidence of localized and advanced STS in Korean patients, their treatment patterns, and the survival of patients by disease status. Materials and methods The STS patient cohort was defined using National Health Insurance Service medical data from 2002 to 2015. Incidence, distribution, anatomical location of tumors, survival rates (Kaplan-Meyer survival function) and treatment patterns were analyzed by applying different algorithms to the STS cohort containing localized and advanced STS cases. Results A total of 7,813 patients were diagnosed with STS from 2007 to 2014, 4,307 were localized STS and 3,506 advanced STS cases. The total incidence of STS was 2.49 per 100,000 person- years: 1.37 per 100,000 person-years for localized STS and 1.12 per 100,000 person-years for advanced STS. The 5-year survival rate after diagnosis was 56.4% for all STS, 82.4% for localized, and 27.2% for advanced STS. Half of the advanced STS patients (49.98%) received anthracycline-containing chemotherapy as initial treatment after diagnosis. Conclusion This study provides insights into localized and advanced STS epidemiology, treatment patterns and outcomes in Korea, which could be used as fundamental data in improving clinical outcomes of STS patients in the future.

Objectives Considering the effect of sex and head of household responsibilities, this study was designed to evaluate whether precarious employment is associated with the development of new-onset severe depressive symptoms. Methods We followed 2214 male and 1276 female waged workers, ≤59 years of age and without moderate depressive symptom, from the Korean Welfare Panel Study 2007–2013. Their employment status was classified as full-time permanent, precarious, self-employed, or unemployed after baseline. Except for occupation and company size, all variables were treated as time-dependent. Severe depressive symptoms were measured using the 11-item Center for Epidemiologic Studies Depression Scale (CES-D-11). A generalized estimating equation was used to evaluate the effect of employment status on the development of new-onset severe depressive symptoms. Results After adjusting for initial baseline CES-D-11 score, chronic disease, and other socioeconomic covariates, precarious employment was associated with the development of new-onset severe depressive symptoms among male heads of household [odds ratio (OR) 1.52, 95% confidence interval (95% CI) 1.02–2.25] and female heads of household (OR 4.19, 95% CI 1.70–10.32). In addition, the transition from full-time permanent employment to another employment status was associated with the development of new-onset severe depressive symptoms among both sexes, with an especially strong association among females. Conclusion The present study suggests that, depending on head of household status and sex, precarious employment is associated with the development of new-onset severe depressive symptoms.

Background: Follow-up clinical consultations could improve overall health status as well provide knowledge and education for cancer prevention. Materials and Methods: This is the cross-sectional study using the Korean Community Health Survey (KCHS) 6th edition for 2012, with 115,083 respondents who underwent cancer checkups selected as subjects. Associations between the presence of consultation and the socioeconomic status were determined using statistical methods with the SAS 9·3 statistical package (Cary, NC, USA). Findings: Among the recipients, 32,179 (28.0%) received clinical consultations after cancer screenings. Those in rural areas (odds ratio, OR=0.71, 95% confidence interval (CI), 0.69-0.73) visited follow-up clinics less frequently than did those in urban areas. Starting at the elementary school level, as the education level increased to middle school (OR=1.26, 95% CI: 1.19-1.34), high school (OR=1.29, 95% CI: 1.23-1.36) or college (OR=1.76, 95% CI: 1.65-1·89), the participation rates also increased. When compared with the lowest quartile group, the quartile income level showed a statistical trend and difference as follows: second lowest quartile (OR=1.11, 95% CI: 1.07-1.16), third lowest (OR=1·12, 95% CI: 1.07-1.17) and highest quartile income (OR=1.29, 95% CI: 1.23-1.35). In addition, the people with economic activities (OR=0.87, 95% CI: 0.84-0.90) visited follow-up clinics less frequently than did the others. Current smokers (OR=0·93, 95% CI: 0.89-0.98) and inveterate drinkers (OR=0.88, 95% CI: 0.85-0.94) had a tendency to visit less often than did non-smokers and other drinkers with all cancers combined. Interpretation: We suggest primary prevention through lifestyle modifications including smoking and drinking, and environmental interventions may offer the most cost-effective approach to reduce the cancer burden.

After 2010, panic disorders became relatively common in South Korea, with many celebrities confessing to the public that they have panic disorder. The annual number of patients with panic disorder and sleep disorder have been gradually increasing. In light of these increases, we analyzed the relationship between sleep disorder and panic disorder. We used national claim data to design a 1:3 nested case-control study. The study included medical claims filed for 29,312 patients during 2004-2013. We performed conditional logistic regression analysis to investigate the relationship between sleep disorder and panic disorder. There were 7436 patients who were diagnosed with panic disorder, and 21,876 patients who were gender- and age-matched as controls. Patients with sleep disorder had higher incidence of panic disorder. In particular, patients with insomnia had the strongest association with panic disorder (adjusted, OR, 1.386; 95% CI, 1.201-1.599; p0.05). These associations were stronger in healthy patients and those with worse socioeconomic status. In conclusion, sleep disorder, in particular, insomnia was positively associated with panic disorder. Thus, healthcare professionals and policy makers should effectively control insomnia and consider strategies for early intervention for vulnerable patients with risk of panic disorder.

Objective To assess whether type of long-term care service is a risk factor of the incidence of pressure ulcers among older adults with dementia who are receiving long-term care insurance (LTCI). Methods Data from LTCI beneficiaries (benefit level 1 or 2) with dementia, aged 60 and older (n = 7841), in the Korean Elderly Cohort data set from 2008 to 2013 were used. Type of long-term care service was categorized into home or institutional care using the LTCI Claims Database. The National Health Insurance Claims Database was used to identify the incidence of pressure ulcers as the outcome variable in a survival analysis using the time-dependent Cox proportional hazard model. Results Of the 7841 participants, 98 (1.2%) exhibited pressure ulcers. Compared with beneficiaries receiving home care, those receiving institutional care had a higher adjusted hazard ratio for pressure ulcers (hazard ratio 6.48, 95% confidence interval 3.48–10.86). These associations were particularly strong among beneficiaries without pressure ulcers during the mandatory assessment for benefit eligibility and who were partially ambulatory. Discussion Beneficiaries receiving institutional care were more likely to have pressure ulcers than were those receiving home care. The government must monitor the quality of institutional long-term care services and encourage service providers to improve such care.

Objectives Catastrophic health expenditure (CHE) means that the medical spending of a household exceeds a certain level of capacity to pay. Previous studies of CHE have focused on benefits supported by the public sector or high medical cost incurred by treating diseases in South Korea. This study examines variance of CHE in these households according to changes in employment status. We also determine whether a relationship exists according to income level. Design A longitudinal study. Setting We used the Korean Welfare Panel Study (KOWEPS) conducted by the Korea Institute. Participants The data came from 5335 households during 2009–2012. Outcome measure CHE, defined as health expenditures that were 40% greater than the ability of the household to pay. Results Households with people who experienced changes in job status from employed to unemployed (OR 2.79, 95% CI 2.06 to 3.78) or were unemployed with no status change (OR 1.57, 95% CI 1.28 to 1.92) were more likely to incur CHE than those containing people who were consistently employed. In addition, low-income families with members who had either lost a job (OR 3.52, 95% CI 2.44 to 5.10) or were already unemployed (OR 1.67, 95% CI 1.29 to 2.16) were more likely to incur CHE than those with family members with a consistent job. Conclusions Given the insecure employment status of people with low income, they are more likely to face barriers in obtaining needed health services. Meeting their healthcare needs is an important consideration.

Relationship on new statin use and the risk of hepatocellular carcinoma (HCC) in patients with incident type 2 diabetes mellitus (T2DM), who might be at the risk of developing HCC, is uncertained. A nationwide population-based nested case-control study was conducted within the National Health Insurance Service National Sample Cohort 2002-2013 in Korea. Newly prescribed statin after newly diagnosed T2DM was defined as statin use. Controls were matched to case patients on age, sex, follow-up time, and the date of diabetes diagnosis at a five-to-one ratio. Odds ratios (ORs) for associations of statin use with HCC were calculated using conditional logistic regression. After at least a 5-year HCC-free period, there were 229 incident HCC cases and 1,145 matched controls from 47,738 patients with incident diabetes. Of these 229 incident HCC cases, 27 (11.8%) were statin users, whereas 378 (33.0%) were statin users among 1,145 controls. Statin use was associated with a reduced risk of HCC development (adjusted OR [AOR]= 0.36, 95% confidence interval [CI] 0.22-0.60) after adjustment for chronic viral hepatitis, liver cirrhosis, alcoholic liver disease, previous cancer, aspirin use, insulin use, sulfonylurea use, metformin use, thiazolidinedione use, history of chronic obstructive pulmonary disease, Charlson comorbidity score, household income level, and residential area. Risk reduction was accentuated with an increase of cumulative defined daily doses (cDDD) compared with non-users (AORs 0.53, 0.36, 0.32, and 0.26 in ≤60, 60-180, 181-365, and365cDDD, respectively; P for trend0.0001). The risk reduction was apparent in the presence of liver disease (AOR = 0.27, 95% CI 0.14-0.50), including heterogeneous groups of clinical diagnosis of liver disease, but not significant in the absence of liver disease (AOR = 0.64, 95% CI 0.32-1.29). Among patients with new onset T2DM, statin use before HCC diagnosis may have a beneficial inhibitory effect on HCC development in a dose-dependent manner, especially in individuals with liver disease.

Introduction: Dementia is the leading cause of disability worldwide in the elderly individuals. Although prior studies have examined psychiatric symptoms in dementia caregivers, few studies have examined physician-diagnosed depression in the family caregiver of a patient with dementia. Methods: We used data from 457 864 respondents from the Korea Community Health Survey. We used logistic regression to examine the relationship between physician-diagnosed depression and cohabitation with a patient with dementia. Results: Cohabitation with a patient with dementia (1.2% of the Korean population) was significantly associated with physician-diagnosed depression. The significance remained in females when the data were stratified by sex. A significant association also occurred among males with low family income. Conclusion: To reduce the burden of dementia, we need a management policy that includes the caregiver as well as the patient with dementia. In particular, political management for the vulnerable population, male caregiver in low-income family and female caregiver in high-income family, should be prepared.

Medical utilization due to organic sleep disorders has increased remarkably in South Korea, which may contribute to the deterioration of mental health in the population. We analyzed the relationship between organic sleep disorders and risk of hospitalization due to mood disorder. We used data from the National Health Insurance Service (NHIS) National Sample Cohort 2002-2013, which included medical claims filed for the 15,537 patients who were newly diagnosed with a mood disorder in a metropolitan region, and employed Poisson regression analysis using generalized estimating equation (GEE) models. By the results, there was a 0.53% hospital admission rate among 244,257 patients with outpatient care visits. Patients previously diagnosed with an organic sleep disorder before specific outpatient care had a higher risk for hospitalization. Such associations were significant in females, patients with a longer duration of disease, or those who lived in the largest cities. In conclusion, considering that experiencing a sleep disorder by a patient with an existing mood disorder was associated with deterioration of their status, health policy makers need to consider insurance coverage for all types of sleep disorders in patients with psychological conditions.

Background South Korea faces difficulties in the management of mental disorders, and those difficulties are expected to gradually worsen. Therefore, we analyzed the relationship between social welfare centers and hospital admission after outpatient treatment for mood disorders. Methods We used data from the National Health Insurance Service National Sample Cohort 2002–2013, which included all medical claims filed for the 50,160 patients who were newly diagnosed with a mood disorder among the 1,025,340 individuals in a nationally representative sample. We performed a logistic regression analysis using generalized estimating equation (GEE) models to examine the relationship between social welfare centers and hospital admission after outpatient treatment for mood disorders (ICD-10: F3). Results There was a 3.9% admission rate among a total of 99,533 person-years. Outpatients who lived in regions with more social welfare centers were less likely to be admitted to a hospital (per increase of five social welfare centers per 100,000 people; OR: 0.958; 95% CI: 0.919–0.999). Social welfare centers had an especially strong protective effect on patients with relatively mild mood disorders and those who were vulnerable to medical expenditures. Conclusions Considering the protective role of social welfare centers in managing patients with mood disorders, health-policy makers need to consider strategies for activating mental healthcare.

Objectives This study investigated the association between employment status and depression. Methods Data from the Korea Welfare Panel Study (KOWEPS) collected from 2008 to 2011 were used. A total of 7368 subjects were included in this study after exclusion of subjects with missing data and those who were self-employed or could not work. Depression was assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Employment status, age, sex, region, education, marital status, income, head of household, self-rated health, smoking status, drinking habits, and the current year9s and the previous year9s CES-D scores were included in the model as independent variables. A generalised linear mixed-effects model for longitudinal binary data was used. Results Compared with those who were permanently employed, individuals who moved from permanent to precarious employment (OR 1.45, 95% CI 1.23 to 1.70) or to unemployment (OR 1.78, 95% CI 1.30 to 2.43) and from precarious employment to unemployment (OR 1.65, 95% CI 1.32 to 2.06) showed a significantly increased the odds of having depression. Continuing precarious employment (OR 1.54, 95% CI 1.30 to 1.83) or unemployment (OR 1.45, 95% CI 1.23 to 1.70) also significantly increased the odds of having depression. These results were particularly identified in men and head of household women. The effects were not significant among non-head of household women. Conclusions Precarious employment and unemployment were clearly associated with having depression. In addition, in view of our findings, policy makers should consider sex and head of household status when developing welfare policies. The inequity between precarious jobs and permanent jobs should be tackled.

Individuals with psychoses show excess mortality, which is a major public health concern. This study examined all-cause and suicide mortality rates in Korean patients diagnosed with schizophrenia, mood disorder, or mental and behavioral disorder due to psychoactive substance use and to compare this with that of the general population. Data were from the National Health Insurance cohort, 2002 to 2013. A total of 107,190 cases aged 15 years or over were included. Mortality rates per 100,000 person years (PY) were obtained. Poisson regression modelling was conducted to quantify the effect of baseline characteristics on all-cause and suicide mortality risks. Standardized mortality ratios (SMRs) were also calculated. All-cause mortality was the highest among mental and behavioral disorder patients (1,051.0 per 100,000 PY), followed by schizophrenia (949.1 per 100,000 PY) and mood disorder patients (559.5 per 100,000 PY). Highest suicide mortality was found in schizophrenia (177.2 per 100,000 PY), mental and behavioral disorder (143.7 per 100,000 PY), and mood disorder patients (59.7 per 100,000 PY). The rate ratios (RRs) for all-cause and suicide mortality were reduced for younger populations and women. Psychoses patients had higher all-cause (schizophrenia, SMR 2.4; 95% confidence interval [CI] 2.2–2.5; mood disorder, SMR 1.4; 95% CI 1.3–1.5; mental and behavioral disorder, SMR 2.6; 95% CI 2.5–2.8) and suicide (schizophrenia, SMR 8.4; 95% CI 7.2–9.6; mood disorder, SMR 2.8; 95% CI 2.1–3.5; mental and behavioral disorder, SMR 6.8; 95% CI 5.7–7.9) mortality rates than the general population. These findings infer that efforts should be made to reduce excess mortality in psychoses., Graphical Abstract

Objectives To examine the sex-specific factors associated with being unaware of one's hepatitis B virus surface antigen (HBsAg) seropositivity status in a large, HBsAg-positive population of Koreans. Methods In total, 1197 subjects aged 19 years or older who were HBsAg-positive according to data from the 2007-2012 Korea National Health and Nutrition Examination Survey were included. Subjects were considered unaware of their HBsAg seropositivity status if they answered that they had no knowledge of being previously infected by the hepatitis B virus (HBV) or diagnosed with HBV hepatitis. Multivariate Poisson regression models with robust variance estimate were used to assess the significance of the variables using weighted frequencies. Results The majority (77.8%) of HbsAg-positive Korean adults (females, 81.9%; males, 74.6%) were unaware of their HBsAg seropositivity status. We found that sex (female: prevalence ratio [PR] 1.19), household income (low: PR, 1.15), marital status (never married: PR, 1.18), self-rated health (moderate: PR, 1.14; good: PR, 1.12), and alcohol use (at least 2-3 times/wk: PR, 1.21) were associated with being unaware. In females, age (50 to 59 years: PR, 1.29; ≥ 70 years: PR, 1.30), household income (low: PR, 1.37; middle-low: PR, 1.24), and marital status (never married: PR, 1.33) were associated with being unaware. In males, self-rated health (moderate: PR, 1.14; good: PR, 1.21) and alcohol use (at least 2-3 times/wk: PR, 1.21) were associated with being unaware. Conclusions Factors related to the socioeconomic status of females and the health-related behaviors of males were found to be associated with being unaware of one's HBsAg seropositivity status.

Background Previous studies have shown that contextual factors and individual socioeconomic status (SES) were associated with mortality in Western developed countries. In Korea, there are few empirical studies that have evaluated the association between SES and health outcomes. Methods We conducted cohort study to investigate the socioeconomic disparity in all-cause mortality for patients newly diagnosed with hypertension in the setting of universal health care coverage. We used stratified random sample of Korean National Health Insurance enrollees (2002–2013). We included patients newly diagnosed with hypertension (n = 28,306) from 2003–2006, who received oral medication to control their hypertension. We generated a frailty model using Cox’s proportional hazard regression to assess risk factors for mortality. Results A total of 7,825 (27.6%) of the 28,306 eligible subjects died during the study period. Compared to high income patients from advantaged neighborhoods, the adjusted hazard ratio (HR) for high income patients from disadvantaged neighborhoods was 1.10 (95% CI, 1.00–1.20; p-value = 0.05). The adjusted HR for middle income patients who lived in advantaged versus disadvantaged neighborhoods was 1.17 (95% CI, 1.08–1.26) and 1.27 (95% CI, 1.17–1.38), respectively. For low income patients, the adjusted HR for patients who lived in disadvantaged neighborhoods was higher than those who lived in advantaged neighborhoods (HR, 1.35; 95% CI, 1.22–1.49 vs HR, 1.28; 95% CI, 1.16–1.41). Conclusions Neighborhood deprivation can exacerbate the influence of individual SES on all-cause mortality among patients with newly diagnosed hypertension. Electronic supplementary material The online version of this article (doi:10.1186/s12939-015-0288-2) contains supplementary material, which is available to authorized users.

Background In 1995, the South Korean government made nutrition labeling compulsory, which has positively impacted patients with certain chronic diseases, such as dyslipidemia. We investigated the association between nutrition labeling-based awareness and the risk of dyslipidemia among individuals not yet diagnosed. Methods Our study used data from the fifth Korea National Health and Nutrition Examination Surveys administered during 2010–2014 (n = 17,687). We performed multiple or logistic regression analysis to examine the association between nutritional analysis and various outcome variables. Results Approximately 70 % of the respondents (n = 11,513) were familiar with nutrition labeling, of which 20 % (n = 3172) decided what food to buy based on that information. This awareness yielded mostly positive results on outcome indicators, such as triglyceride and high-density lipoprotein cholesterol levels. In general, individuals who used nutritional labels to make decisions regarding food purchases had a lower risk of dyslipidemia than individuals who did not (OR: 0.806, 95 % CI: 0.709–0.917). Conclusion Utilizing nutrition labels for making food choices correlated with a lower risk of dyslipidemia in certain subgroups. Based on our findings, we recommend that health policymakers and medical professionals consider promoting nutrition labeling as an alternative method for managing certain chronic diseases in South Korean patients.