South Korean Population Research Articles

Comparison of Trends in the Incidence of Traumatic Spinal Cord Injury in Daily Life, Automobile Accidents, and Industrial Accidents: A National Multi-Insurance Study in Korea.

To examine the incidence of traumatic spinal cord injury (TSCI) from all etiologies, we measured and compared the incidence of TSCI from three national or quasi-national databases in South Korea, namely, the National Health Insurance Service (NHIS), automobile insurance (AUI), and Industrial Accident Compensation Insurance (IACI). We reviewed patients with TSCI reported in the NHIS database between 2009 and 2018, and in the AUI and IACI databases between 2014 and 2018. TSCI patients were defined as those first admitted to the hospital with a diagnosis of TSCI according to the International Classification of Diseases (10th revision) criteria. Age-adjusted incidence was calculated using direct standardization using the 2005 South Korean population or the 2000 US population as the standard population. The annual percentage changes (APC) of TSCI incidence were calculated. The Cochrane-Armitage trend test was performed according to the injured body region. In the NHIS database, age-adjusted TSCI incidence using the Korean standard population increased significantly from 2009 to 2018 (from 33.73 per million in 2009 to 38.14 per million in 2018, APC = 1.2%, P = 0.014). Contrarily, age-adjusted incidence in the AUI database significantly decreased from 13.88 per million in 2014 to 11.57 per million in 2018 (APC = - 5.1%, P = 0.009). In the IACI database, the age-adjusted incidence showed no significant difference, while crude incidence showed a significant increase (from 22.02 per million in 2014 to 28.92 per million in 2018, APC = 6.1%, P = 0.038). According to the age group, all the three databases showed high incidences of TSCI in those in their 60s and 70s or older. Among those in their 70s or older, the incidence of TSCI increased dramatically in the NHIS and IACI databases, while no significant trend was found in AUI database. In 2018, the number of TSCI patients was the highest among those over 70 years of age in the NHIS, whereas among those in their 50s were the highest in both AUI and IACI. The proportion of patients with cervical spinal cord injury was the most common in all these databases. The differences in trends in the incidence of TSCI may be due to the different etiologies and different characteristics of subjects depending on insurance type. These results imply the need for tailored medical strategies for the different injury mechanisms represented by three national insurance services in South Korea.

The Association of Body Mass Index and Waist Circumference with the Risk of Achilles Tendon Problems: A Nationwide Population-Based Longitudinal Cohort Study.

The purpose of this study was to evaluate the association of body mass index (BMI) and waist circumference (WC) with the risk of Achilles tendinopathy (AT) or Achilles tendon rupture (ATR), using data from a nationwide population-based cohort. We hypothesized that higher BMI and WC would be independently associated with the increased risk of AT or ATR. In addition, a higher WC may potentiate the association between BMI and the risk of Achilles tendon problems. We used the National Health Insurance database that covers the entire South Korean population to follow up subjects who participated in the National Health Screening Program (NHSP) from January 2009 to December 2010. The NHSP data include subjects' BMI, WC, blood test results, blood pressure, and information about lifestyle. Among the subjects, those who were newly diagnosed as having AT or ATR before December 31, 2017, were selected. To examine the association of the variables with the risk of AT or ATR and determine whether the effect of higher BMI varied according to WC, multivariate Cox proportional hazards regression was used. Among a total of 16,830,532 subjects, 125,814 and 31,424 developed AT and ATR, respectively. A higher BMI showed a greater association with the increased risk of ATR than AT (adjusted hazard ratio [HR], 3.49 vs. 1.96). A higher WC was associated with the increased risk of AT (adjusted HR, 1.22), but not ATR. In a separate analysis, the association between BMI and the risk of AT was higher when subjects had higher WC as compared to those with lower WC, being most significant in individuals with both higher BMI and higher WC. Higher BMI was more associated with the increased risk of ATR than AT. Moreover, a high central fat distribution played an independent and potentiating role in the development of AT. This implies the greater importance of a high central fat distribution contributing to the development of AT in obese people.

Temporal trends in heart failure over 11 years in the aging Korean population: A retrospective study using the national health insurance database.

Understanding national trends of heart failure (HF) is crucial for establishing prevention and treatment strategies. We aimed to investigate the 11-year trends of HF in the South Korean population. Using the Korean National Health Insurance Service database, we identified 3,446,256 patients with HF between 2004 and 2014. The prevalence of HF was 1.42% in 2004, steadily increasing to 1.98% in 2014. However, the age-adjusted prevalence of HF remained stable (1.43% in 2014). The incidence of HF was 6.1/1000 person-years in 2004 and remained at similar levels, reaching 5.4/1000 person-years in 2014. The age-adjusted incidence of HF slowly decreased to 3.94/1000 person-years in 2014. The event rate for hospitalized patients with HF remained stable increasing from 1.40 in 2004 to 1.87/1000 person-years in 2014, and the age-adjusted event rate of hospitalized HF decreased to 1.22 in 2014. In South Korea, between 2004 and 2014, the prevalence of HF increased while the incidence of HF remained stable. Furthermore, the age-adjusted HF prevalence was stable, and the age-adjusted incidence decreased. This indicates that the aging population is the main cause of the increasing national burden associated with HF and that further attention is warranted in the management of HF in older adults.

Incidence and Prevalence of Peripheral Arterial Disease in South Korea: Retrospective Analysis of National Claims Data.

Peripheral arterial disease (PAD) causes blood vessel narrowing that decreases blood flow to the lower extremities, with symptoms such as leg pain, discomfort, and intermittent claudication. PAD increases risks for amputation, poor health-related quality of life, and mortality. It is estimated that more than 200 million people worldwide have PAD, although the paucity of PAD research in the East detracts from knowledge on global PAD epidemiology. There are few national data-based analyses or health care utilization investigations. Thus, a national data analysis of PAD incidence and prevalence would provide baseline data to enable health promotion strategies for patients with PAD. This study aims to identify South Korean trends in the incidence and prevalence of PAD and PAD treatment, in-hospital deaths, and health care utilization. This was a retrospective analysis of South Korean national claims data from 2009 to 2018. The incidence of PAD was determined by setting the years 2010 and 2011 as a washout period to exclude previously diagnosed patients with PAD. The study included adults aged ≥20 and <90 years who received a primary diagnosis of PAD between 2011 and 2018; patients were stratified according to age, sex, and insurance status for the incidence and prevalence analyses. Descriptive statistics were used to assess incidence, prevalence, endovascular revascularization (EVR) events, amputations, in-hospital deaths, and the health care utilization characteristics of patients with PAD. Based on data from 2011 to 2018, there were an average of 124,682 and 993,048 incident and prevalent PAD cases, respectively, in 2018. PAD incidence (per 1000 persons) ranged from 2.68 to 3.09 during the study period. From 2012 to 2018, the incidence rate in both sexes showed an increasing trend. PAD incidence continued to increase with age. PAD prevalence (per 1000 persons) increased steadily, from 3.93 in 2011 to 23.55 in 2018. The number of EVR events varied between 933 and 1422 during the study period, and both major and minor amputations showed a decreasing trend. Health care utilization characteristics showed that women visited clinics more frequently than men, whereas men used tertiary and general hospitals more often than women. The number of incident and prevalent PAD cases generally showed an increasing trend. Visits to tertiary and general hospitals were higher among men than women. These results indicate the need for attention not only to Western and male patients, but also to Eastern and female patients with PAD. The results are generalizable, as they are based on national claims data from the entire South Korean population, and they can promote preventive care and management strategies for patients with PAD in clinical and public health settings.

Association of the "Weekend Warrior" and Other Physical Activity Patterns with Metabolic Syndrome in the South Korean Population.

These days, it is not common for people to have time to do physical activities regularly because of their own work. So, they perform physical activities all at once, which is often called the “weekend warrior”. Therefore, this study aimed to examine the association of the “weekend warrior” and other physical activity patterns with metabolic syndrome. Data from the Korea National Health and Nutrition Examination Survey were used, and 27,788 participants were included. The participants were divided into inactive, weekend warriors, and regularly active based on physical activity patterns. The risk of metabolic syndrome in each group was analyzed using multiple logistic regression. The inactive and weekend warrior groups showed a higher likelihood of developing metabolic syndrome than the regularly active groups (weekend warrior: odds ratio (OR) 1.29, confidence interval (CI) 1.02–1.65; inactive: OR 1.38, CI 1.25–1.53). According to the physical activity patterns, the weekend warrior group showed a dose-response relationship compared to the regularly active group (only moderate: OR 1.85, CI 1.25–2.72; only vigorous: OR 1.41, CI 0.93–2.14; both: OR 0.84, CI 0.56–1.27). This study found increasing the amount of physical activity and performing vigorous-intensity physical activity helped manage metabolic syndrome in the weekend warrior group.

Economic burden of opioid misuse focused on direct medical costs.

Background: Since their development, synthetic opioids have been used to control pain. With increased opioid use, problematic opioid prescription has also increased, resulting in a growing economic burden. However, there is a paucity of research studies on the economic burden of prescription opioid misuse in Asia, especially South Korea. Objectives: To estimate the incremental economic burden of prescription opioid misuse for the South Korean population. Methods: The National Health Insurance Service-National Sample Cohort database, covering 2% of the South Korean population between 2010 and 2015, was analyzed. Outpatients aged 18 or older who took one or more prescription opioids were selected. Based on their opioid prescription patterns, patients were classified into opioid misuse and non-misuse groups. The direct medical costs per person per year (PPPY) and the incremental economic burden of the opioid misuse group were explored using an exponential conditional model with a suitable distribution and log link function. All analyses were performed using SAS® Enterprise Guide version 9.4, and p < 0.05 was considered statistically significant. Results: The number of patients who had ≥1 opioid prescription was 345,020 including 84,648 (24.53%) in the opioid misuse group and 260,372 (75.47%) in the non-misuse group. The adjusted mean direct medical costs PPPY were estimated to be USD 401 for the opioid misuse group, which is 1.49 times significantly higher than that for the non-misuse group (p < 0.0001). The incremental economic burden of the opioid misuse group in the South Korean population was estimated to be approximately USD 0.52 billion for the period 2010-2015. Conclusion: Prescription opioid misuse was significantly associated with the increased economic burden. Along with proper policies for using opioids, it is necessary to monitor opioid prescription patterns to prevent opioid misuse and reduce the related economic burden.

Association between smoking status and subjective quality of sleep in the South Korean population: a cross-sectional study.

This study aimed to investigate the relationship between smoking and subjective sleep quality in the Korean adult population. We designed a cross-sectional survey using data from the 2018 Korean Community Health Service Conditions Survey and selected smoking status as our variable of interest. We divided the participants into people who currently, never, and formerly smoked, those who smoked < 20 cigarettes/day, and those who smoked > 20 cigarettes/day. Subjective sleep quality was analyzed using the Pittsburgh Sleep Quality Index. Multiple logistic regression analysis was performed for statistical analysis. A total of 174,665 participants were enrolled. People who formerly and currently smoked were found to have poorer subjective sleep quality than those who never smoked. The odds of poor subjective sleep quality in people who smoked > 20 cigarettes/day were 1.15 times (95% confidence interval: 1.09-1.21) for men and 1.51 times (95% confidence interval: 1.22-1.86) for women, compared with men and women who never smoked. Smoking was negatively associated with subjective sleep quality. Smoking cessation programs and lifestyle improvement education may be justifiable to improve the quality of sleep in Korean adults.

Dyslipidemia is Associated with an Increased Risk of Achilles Tendinopathy and Tendon Rupture to a Greater Extent in Underweight Than in Obese Subjects

Category: Ankle Introduction/Purpose: The association between dyslipidemia and Achilles tendinopathy (AT) or Achilles tendon rupture (ATR) remains controversial, although some studies have been reported on the subject. This study aimed to evaluate the correlation of dyslipidemia and the risk of AT or ATR, and its association with body mass index (BMI), by assessing data from a nationwide population-based cohort. Methods: We used the National Health Insurance database, which includes the entire South Korean population to follow-up subjects who participated in the National Health Screening Program (NHSP) from January 2009 to December 2010. Participants diagnosed with AT or ATR before December 31, 2017, were selected. The variables were age, sex, frequency of high-intensity exercise per week, BMI, waist circumference, low-density lipoprotein cholesterol (LDL-C) levels, triglyceride (TG) levels, high- density lipoprotein cholesterol (HDL-C) levels, fasting blood glucose levels, and systolic blood pressure. Multivariate Cox proportional hazards regression was used for data analysis. Results: A total of 16,830,532 subjects were included. Of these, 125,814 and 31,424 subjects developed AT and ATR, respectively. A higher level of LDL-C was associated with an increased risk of both AT (adjusted hazard ratio [HR], 1.16) and ATR (adjusted HR, 1.18). A slightly increased risk of AT was observed in subjects with higher TG levels (adjusted HR, 1.03), whereas higher HDL-C level was associated with a slight risk reduction for AT (adjusted HR, 0.95). However, no significant association was observed between higher TG or HDL-C levels and ATR. In the underweight group (BMI &lt; 18.5 kg/m2), a higher LDL-C level was associated with an increased risk of AT and ATR by 37 and 116%, respectively, compared with lower LDL-C. Higher LDL-C levels was associated with an increased risk of AT and ATR by 10 and 16%, respectively, in the obese group (BMI &gt;= 25 kg/m2). Conclusion: Our results support the hypothesis that dyslipidemia was related to the development of AT and ATR. The association of higher LDL-C levels with AT and ATR risk was more pronounced in underweight than in overweight and obese subjects.

Impact of Sleep Duration on Decline in Kidney Function in Adult Patients with Hypertension: A Community-Based Prospective Cohort Study.

BackgroundSleep duration is associated with various health conditions, including chronic kidney disease. However, the association between sleep duration and decline in kidney function in the South Korean population remains unclear. We aimed to investigate the impact of sleep duration on kidney function decline in adult patients with hypertension.MethodsThis cohort study was performed using data obtained from the Korean Genome and Epidemiology Study; 2,837 patients with hypertension who initially had normal kidney function were included. Glomerular filtration rates (GFRs) were estimated at baseline and throughout the 16 years of follow-up. A person was considered to have a decline in kidney function if they had a GFR <60 mL/min/1.73 m2. Sleep duration data were obtained through interviewer-assisted questionnaires. Sleep durations were classified as short (<6 hours), normal (≥6 hours but <9 hours), and long (≥9 hours). The Cox proportional hazards model was applied, with adjustments for covariates.ResultsAfter adjusting for covariates, sleep duration was not associated with a decline in kidney function. However, among men with poorly controlled hypertension at baseline, compared to men with normal sleep durations, men with sleep durations <6 hours had a significantly higher risk of kidney function decline (hazard ratio, 1.56; 95% confidence interval, 1.02–2.36).ConclusionShort sleep duration did not seem to be associated with an increased risk of decline in kidney function; however, it may be a risk factor for the decline in kidney function in men with poorly controlled hypertension.

Association between use of antacid medications (proton pump inhibitors and histamine-2 receptor antagonists) and the incidence of lung cancer: A population-based cohort analysis.

This study investigated the association between antacid administration and lung cancer incidence in a real-world setting. This was a nationwide, retrospective cohort study. The cohort comprised random samples (n = 1,031,392) from the entire South Korean population in 2002. The duration of antacid administration between January 2006 and December 2010 was recorded for each participant. Newly developed lung cancers were counted during the 5-year observation period (January 1, 2006 to December 31, 2010). A total of 437,370 participants aged ≥ 40 years were included, of whom 301,201 (68.9%) had antacid exposure before the diagnosis of lung cancer. A total of 1230 (0.28%) antacid-exposed patients developed lung cancer. Among patients with no antacid exposure or underexposure (n = 136,171), 597 (0.44%) developed lung cancer. In the multivariable analysis, antacid exposure before the diagnosis of lung cancer was independently associated with a reduced incidence of lung cancer (hazard ratio: 0.64; 95% confidence interval: 0.55-0.74; P < .001). Antacid use might be independently associated with a decreased risk of lung cancer development in this cohort study.

Association of myocardial infarction and angina pectoris with obesity and biochemical indices in the South Korean population

The best obesity index for myocardial infarction or angina pectoris (MIAP) risk assessment remains controversial. Furthermore, the association between biochemical indices and these diseases is unclear. This study examined associations of obesity and biochemical indices with MIAP in the Korean population. This large-scale cross-sectional study was based on the Korea National Health and Nutrition Survey dataset from 2010 to 2019. A total of 22,509 subjects (9452 men and 13,057 women) aged ≥ 50 years were included. Participants consisted of 21,426 individuals without MIAP (men = 8869, women = 12,557) and 1083 with MIAP (men = 583, women = 500). Binary logistic regression was performed to examine the association of MIAP with obesity and biochemical indices. The prevalence of MIAP in Korean adults aged ≥ 50 years was 4.81% (6.57% among men, 3.98% among women). MIAP was more strongly associated with total cholesterol than other variables in men (adjusted OR = 0.436 [0.384–0.495], adjusted p < 0.001) and women (adjusted OR = 0.541 [0.475–0.618], adjusted p < 0.001). The waist-to-height ratio (adjusted OR = 1.325 [1.082–1.623], adjusted p = 0.007) and waist circumference (adjusted OR = 1.290 [1.072–1.553], adjusted p = 0.007) showed a significant association with MIAP in men, with no association between obesity indices and MIAP in women after adjustment. The association between biochemical indices and MIAP differed slightly according to sex. Only total cholesterol, creatinine, and platelets were associated with MIAP in both men and women.

COVID-19 Double-Decrement Model Forecasting for South Korean Population

Since the first case in November 2019, COVID-19 has spread fast, infected many people, and taken many lives. Once COVID-19 cases are confirmed, and hospital treatments are required, they will need high costs yet still be at risk of death. Therefore, insurance companies and social service providers need a reliable model to estimate the expenses and ensure their financial health. This study discusses the modeling of time-until-release and time-until-death since cases are confirmed, using the South Korean data. Double-decrement model is assumed to follow Weibull and log-logistic hazard for time-until-release and time-until-death, respectively. Considered risk factors are sex, symptoms, age group, and the month when the case is confirmed. The nonlinear survival regression model is proposed, with the Solver function in Microsoft Excel for parameter estimation. The results suggest that virus lifespan and mortality risk get lower over time. Time-until-death is also lower, implying that we have less time to save lives from mortality risk. More frequent testing with faster results and not waiting for the symptoms to occur is needed for people under thirty years old due to shorter time-until-death and those at sixty and above due to higher case fatality rates. Full dose vaccination must be prioritized for ages sixty and above to save as many lives as possible.

Epidemiology and Clinical Characteristics of Older Patients Transferred from Long-Term-Care Hospitals (LTCHs) to Emergency Departments by a Comparison with Non-LTCHs in South Korea: A Cross-Sectional Observational Study.

The South Korean population is rapidly aging, and the number of older patients in long-term-care hospitals (LTCHs) continues to increase. This study aims to investigate the epidemiologic data, characteristics, and clinical outcomes of patients aged 65 years and older transferred from LTCHs to emergency departments (EDs). This is a retrospective study based on National Emergency Department Information System data from 2014 to 2019. Of the 6,209,695 older patients visiting EDs for disease treatment, 211,141 (3.4%) were transferred from LTCHs. Among patients from LTCHs (211,141), 24.2% were discharged from EDs, 43.0% were admitted to general wards, 20.7% were hospitalized in intensive care units, 3.1% were transferred to another hospital, 6.1% returned to LTCHs, and 2.1% died in EDs. ED stays were the longest for those returning to LTCHs (710.49 ± 1127.43 min). Foley catheterization (40.3%) was most frequently performed in preventable ED visits. In South Korea, older patients being discharged from the ED or returning to LTCHs, after being transferred from LTCHs to EDs, increased. ED stays among older LTCH patients were longer than among non-LTCH older patients, contributing to congestion. To reduce avoidable transfer to EDs from LTCHs, it is necessary to discuss policies, such as expanding appropriate medical personnel and transitional treatment.

Impact of COVID-19 on cancer screening in South Korea

The coronavirus disease (COVID-19) pandemic significantly declined cancer screening rates worldwide. Its impact on the South Korean population is unclear, depending on socioeconomic status (SES), residence, and history of chronic disease. This study utilized data (2018–2020) from the Korean National Cancer Screening Survey, an annual cross-sectional study employing nationally representative random sampling. Cancer screening rates were defined as the proportion of the eligible population who received respective cancer screening within the last 1 year and investigated four major cancers (stomach, colorectal, breast, and cervical). Screening rates every year were compared with screening rate ratios (SRRs) and the corresponding 95% confidence intervals (CIs). Between 2019 and 2020, screening rates declined significantly by 23%, 17%, 12%, and 8% for colorectal cancer (SRR 0.77; 95% CI 0.73–0.82), stomach cancer (SRR 0.83; 95% CI 0.79–0.87), breast cancer (SRR 0.88; 95% CI 0.82–0.93), and cervical cancer (SRR 0.92; 95% CI 0.87–0.97), respectively. Regardless of cancer type, screening was significantly lower in metropolitan residents, those with higher SES, and, interestingly, those without a history of chronic diseases. The significant decline in cancer screening during the pandemic requires urgent political intervention to reduce the burden of future cancer incidence and mortality.

Prevalence and Complications of Glycogen Storage Disease in South Korea: A Nationwide Population-Based Study, 2007-2018.

Glycogen storage disease (GSD) is a rare disease that can cause life-threatening problems owing to metabolic errors in storing or using glycogen. The disease course of GSD remains unknown, despite medical technology advances. We determined the prevalence and complications of GSD using data from the National Health Insurance Service database. Data were collected and analyzed for the entire South Korean population with GSD during 2007–2018. GSD was defined as a combination of disease code E74.0 and rare incurable disease insurance code V117, a unique disease code combination for GSD in South Korea. Overall, 23,055 patients had the E74 disease code; 404 had an additional V117 insurance code. Most GSD patients were aged <10 years. Many complications were identified, the most common being hepatomegaly, hyperuricemia, and elevated liver enzyme levels. The most prescribed drug was α-glucosidase, followed by allopurinol. Seventy-two percent of patients were treated in pediatrics. Twenty-five patients underwent liver transplantation, and 14 died after GSD diagnosis. In South Korea, more patients than expected had GSD diagnosis and were managed accordingly. GSD causes many complications and hospitalizations, resulting in high medical expenses. Serious complications can result in liver transplantation and, eventually, death in some cases. Although the patients' condition was identified only by the disease code, this is the first study to present the current situation of GSD patients in South Korea. Because GSD patients can have dangerous medical conditions, they should be managed consistently while minimizing various complications that may occur with optimal metabolic control.

Is the Number of Missing Teeth Associated With Mortality? A Longitudinal Study Using a National Health Screening Cohort.

This study aimed to estimate the risk of mortality related to the number of missing teeth in a South Korean population. The ≥ 40-year-old population of the Korean National Health Insurance Service-Health Screening Cohort 2002–2003 was analyzed. Participants were selected from a total of 220,189 participants and included in groups of 0 teeth lost, 1–2 teeth lost, and ≥ 3 teeth lost. Among the total population, 17,211 participants were included in no missing teeth, 1–2 missing teeth, and ≥ 3 missing teeth and were randomly matched 1:1:1 for age and sex. Mortality from specific causes and all-cause mortality were compared among the groups. The hazard ratio (HR) of the number of missing teeth for all-cause mortality or each cause of mortality was analyzed using Cox proportional hazard models. According to the cause of death, the HRs for metabolic disease, digestive disease, and trauma were greater in the group with ≥ 3 missing teeth than in the no missing teeth group. The group with ≥ 3 missing teeth indicated a 1.19-fold higher HR for all-cause mortality than the no missing teeth group [95% confidence intervals (95% CIs) = 1.12–1.27, P < 0.001]. The group with 1- 2 missing teeth did not show a higher HR for all-cause mortality. In the group with 1–2 missing teeth, the HRs for mortality from mental disease and digestive disease were higher than those in the no missing teeth group. The group with 1–2 missing teeth did not show a higher HR for all-cause mortality. The number of missing teeth was linked with a higher risk of mortality. For specific causes of mortality, mortality from metabolic disease, digestive disease, and trauma was higher in the participants with the number of missing teeth.

Association between sleep quality and depressive symptoms

BackgroundDepression is a common mental health disorder. Despite sleep disturbance being associated with depression, limited data regarding the association of sleep quality with depression exists. We aimed to investigate the association between sleep quality and depressive symptoms in the South Korean population. MethodsThis cross-sectional study used data from the 2018 Korean Community Health Survey, a nationwide representative survey conducted annually at national public health centers since 2008. The study population comprised 176,794 individuals (78,356 male and 98,438 female) aged 19 years and over. Sleep quality was measured using the Korean version of Pittsburgh Sleep Quality Index and depressive symptoms with the Patient Health Questionnaire-9. Data were analyzed using multiple logistic regression. ResultsThe average PSQI score was 5.03 for men and 5.98 for women. Individuals of both sexes with poor sleep quality were more likely to be depressed (men: odds ratio (OR) = 7.02 [95% confidence interval (CI) = 6.17–7.99]). In subgroup analysis stratified by independent variables, participants with the following characteristics had greater association between poor sleep quality and depressive symptoms: unmarried, college or higher education, white-collar occupation, current smoker, frequent drinker, walking physical activity, and no-stress. LimitationsLimitations included the cross-sectional nature of the study, use of only secondary data and a self-rated questionnaire for evaluating depressive symptoms, and inherent limitations in the PSQI. ConclusionsPoor sleep quality may contribute to depressive symptoms among Korean adults. Screening for poor sleep quality and implementing measures to improve sleep behaviors may prevent the onset of depression.

Health-Related Quality of Life According to Sociodemographic Characteristics in the South Korean Population.

Health-related quality of life (HRQoL) concerns satisfaction with life and happiness with regard to physical, mental, and social factors. RAND-36 is a publicly available, self-administered questionnaire that examines eight health dimensions. This study evaluated the HRQoL of the South Korean population using the RAND-36 questionnaire and compared HRQoL across sociodemographic characteristics. From May 2015 to May 2019, South Koreans who visited public places aged 19–80 years were recruited and the RAND-36 questionnaire was administered. Overall, 1002 participants were recruited (mean age 45.34 years, 52% men). Men scored better than women in both physical and mental health (p < 0.05). There were significant differences in bodily pain (p < 0.05), general health perception (p < 0.05), and energy/fatigue (p < 0.05) dimensions according to the participants’ health condition. The HRQoL of South Koreans was lower than average in most dimensions compared with other countries. As the first study to assess this, its data can be used in future studies that apply RAND-36 to evaluate the HRQoL of diseased individuals, as they can compare their findings with those of our study population.

Attitudes toward the Legalization of Euthanasia or Physician-Assisted Suicide in South Korea: A Cross-Sectional Survey.

This study aimed to investigate the general South Korean public attitudes toward the legalization of euthanasia or physician-assisted suicide (EAS) and examine the reasons underpinning these attitudes. From March–April 2021, we conducted a cross-sectional survey of a representative national sample of 1000 South Koreans aged 19 years or older. Three in four participants (76.4%) expressed positive attitudes toward the legalization of EAS. Participants who agreed with this legalization reported “meaninglessness of the rest of life” and “right to a good death” as their main reasons. Participants who disagreed with the legalization of EAS reported “respect for life”, “violation of the right to self-determination”, “risk of abuse or overuse”, and “violation of human rights” as theirs. In the multivariate logistic regression analyses, participants with poor physical status (adjusted odds ratio [aOR]: 1.41, 95%; confidence interval [CI]: 1.02–1.93) or comorbidity (aOR: 1.84, 95%; CI: 1.19–2.83) showed positive attitudes toward the legalization of EAS. In summary, most of the general South Korean population regards the legalization of EAS positively, especially participants with poor physical status or comorbidity.

Previous psychiatric disorders in the multistep hypothesis of amyotrophic lateral sclerosis: a South Korean population study

Objective: There is accumulating evidence about an association between amyotrophic lateral sclerosis (ALS) and psychiatric disorders. We aimed to investigate the prevalence of previous psychiatric disorders before ALS onset and evaluate the contribution of psychiatric disorders to the number of steps toward developing ALS. Methods: We analyzed the National Health Insurance claims data from 2011 to 2017 and calculated the incidence of ALS. We created a multistep model using the linear least squares method with regression of the log incidence against the log age. Results: The mean annual incidence of ALS was 0.95/100,000 and frequency of familial ALS (fALS) was 5.89%. The proportions of patients who had psychiatric disorders before ALS diagnosis were 36.8% and 47.0% in fALS and sporadic ALS (sALS), respectively (p = 0.009). In both fALS and sALS, depressive disorders and anxiety and stress disorders were relatively frequent, whereas psychotic disorders and bipolar disorders were rare. Further, the slope estimates for regression analyses were 3.50 (R2 = 0.94) and 3.56 (R2 = 0.99) for fALS and sALS, respectively, suggesting a 4–5-step process to ALS onset. However, slope estimates did not differ between sALS patients with pre-symptomatic psychiatric disorders and those without. Conclusions: The incidence of ALS is relatively low in Korea and fewer steps are required to develop ALS compared to Western populations (all 6 steps). Although the prevalence of previous depression or anxiety is seemingly high, the multistep model provides no evidence that these conditions modify the risk of developing ALS in our cohort.