Factors associated with the suicide rates in Korea

Understanding the Fluctuations in Korea's Suicide Rates: A Change-Point Analysis and Interrupted Time Series Analysis

BACKGROUND

Korea has witnessed significant fluctuations in its suicide rates in recent decades, which may be related to modifications in its death registration system. This study aimed to explore the structural shifts in suicide trends, as well as accidental and ill-defined deaths in Korea, and to analyze the patterns of these changes.

METHODS

We analyzed age-adjusted death rates for suicides, deaths due to transport accidents, falls, drowning, fire-related incidents, poisonings, other external causes, and ill-defined deaths in Korea from 1997 to 2021. We identified change-points using the 'breakpoints' function from the 'strucchange' package and conducted interrupted time series analyses to assess trends before and after these change-points.

RESULTS

Korea's suicide rates had three change-points in February 2003, September 2008, and June 2012, characterized by stair-step changes, with level jumps at the 2003 and 2008 change-points and a sharp decline at the 2012 change-point. Notably, the 2003 and 2008 spikes roughly coincided with modifications to the death ascertainment process. The trend in suicide rates showed a downward slope within the 2003-2008 and 2008-2012 periods. Furthermore, ill-defined deaths and most accidental deaths decreased rapidly through several change-points in the early and mid-2000s.

CONCLUSION

The marked fluctuations in Korea's suicide rate during the 2000s may be largely attributed to improvements in suicide classification, with potential implications beyond socio-economic factors. These findings suggest that the actual prevalence of suicides in Korea in the 2000s might have been considerably higher than officially reported.

Factors Associated with End-Of-Life Health Care Use and Spending in Korea in Comparison with the General Population

This study investigated the factors associated with end-of-life health care use and spending in Korea. Chronically ill decedents, who were hospitalized for one of nine chronic conditions during the year before death, were identified from the National Health Insurance Database in 2017. For comparison, the end-of-life care spending for all decedents and the annual health care spending for the general population were analyzed. The inpatient and outpatient end-of-life care spending for the chronically ill decedents were sixteen and seven times the annual inpatient and outpatient spending for the general population respectively. The regional income level was positively associated with both inpatient and outpatient spending among the decedents with a stronger association in the chronically ill decedents, while a negative association was found in the general population. No significant association was found between the inpatient spending and the number of hospital beds for the chronically ill decedents, whereas the number of beds in small to medium-sized hospitals was positively associated with inpatient spending for the total decedents and the general population. The findings suggest that hospitalization for end-of-life care depends more on the income of the patients, while the inpatient spending for total decedents and the general population are more likely to be affected by the supply of beds.

The relative importance of macro versus micro geographical scale in explaining suicide variation in Seoul, South Korea 2014–2016

Background

As ecological factors are getting attention as important determinants of suicide, it is important to identify the unit at which the largest variation exists for more tailed strategy to prevent suicide. We examined the relative importance of two administrative levels for geographic variation in the suicide rate between 2014–2016 in Seoul, the capital city of Korea.

Methods

Two-level linear regression with Dongs (level 1) nested within Gus (level 2) was performed based on suicide death data aggregated at the Dong-level. We performed pooled analyses and then year-stratified analyses. Dong-level socioeconomic status and environmental characteristics were included as control variables.

Results

The overall age- and sex- standardized suicide rate across all Dongs decreased over time from 24.9 deaths per 100,000 in 2014 to 23.7 deaths in 2016. When Dong and Gu units were simultaneously considered in a multilevel analysis, most of the variation in suicide rate was attributed to within-Gu, between-Dong differences with a contribution of Gu-level being small and decreasing over time in year (Variance partitioning coefficient of Gu = 5.3% in 2014, <0.1% in 2015 and 2016). The number of divorce cases per 100,000 explained a large fraction of variation in suicide rate at the Dong-level.

Conclusions

Findings from this study suggest that ecological micro-area unit is more important in reducing the geographic variation in the suicide rate. More diverse ecological-level data needs to be collected for targeted area-based suicide prevention policies in Korea.

Neuroprotective Natural Products’ Regulatory Effects on Depression via Gut–Brain Axis Targeting Tryptophan

L-tryptophan (Trp) contributes to regulating bilateral communication of the gut–brain axis. It undergoes three major metabolic pathways, which lead to formation of kynurenine, serotonin (5-HT), and indole derivatives (under the control of the microbiota). Metabolites from the principal Trp pathway, kynurenic acid and quinolinic acid, exhibit neuroprotective activity, while picolinic acid exhibits antioxidant activity, and 5-HT modulates appetite, sleep cycle, and pain. Abnormality in Trp plays crucial roles in diseases, including depression, colitis, ulcer, and gut microbiota-related dysfunctions. To address these diseases, the use of natural products could be a favorable alternative because they are a rich source of compounds that can modulate the activity of Trp and combat various diseases through modulating different signaling pathways, including the gut microbiota, kynurenine pathway, and serotonin pathway. Alterations in the signaling cascade pathways via different phytochemicals may help us explore the deep relationships of the gut–brain axis to study neuroprotection. This review highlights the roles of natural products and their metabolites targeting Trp in different diseases. Additionally, the role of Trp metabolites in the regulation of neuroprotective and gastroprotective activities is discussed. This study compiles the literature on novel, potent neuroprotective agents and their action mechanisms in the gut–brain axis and proposes prospective future studies to identify more pharmaceuticals based on signaling pathways targeting Trp.

Suicide Risk in Survivors of Acute Respiratory Distress Syndrome: A Nationwide Cohort Study in South Korea

OBJECTIVE

We aimed to examine the prevalence and risk factors of suicide among patients with acute respiratory distress syndrome (ARDS).

METHODS

Data were extracted from the National Health Insurance Service database in South Korea. This study included all adults admitted to intensive care units with a diagnosis of ARDS from January 1, 2010 to December 31, 2019, who survived ≥365. The primary endpoint in this study was suicide within 1 year of an ARDS diagnosis, which was determined as death by a suicide attempt or self-harm.

RESULTS

Analysis included 9,928 patients identified as ARDS survivors. One-year all-cause mortality occurred in 5,021 patients, 186 (1.9%) of which died by suicide. In multivariable Cox regression, older age, continuous renal replacement therapy, cardiopulmonary resuscitation incidence, history of self-harm or attempted suicide and concurrent substance abuse were associated with a higher risk of death by suicide among ARDS survivors.

CONCLUSION

During the 1-year follow-up period, 1.9% of ARDS survivors died by suicide in South Korea, and some factors were identified as potential risk factors for death by suicide. Knowledge of the factors associated with suicide might allow for earlier intervention to potentially reduce the death by suicide among ARDS survivors.

Suicide rate and social environment characteristics in South Korea: the roles of socioeconomic, demographic, urbanicity, general health behaviors, and other environmental factors on suicide rate

BACKGROUND

Suicide is a serious worldwide public health concern, and South Korea has shown the highest suicide rate among Organisation for Economic Co-operation and Development (OECD) countries since 2003. Nevertheless, most previous Korean studies on suicide had limitations in investigating various social environment factors using long-term nationwide data. Thus, this study examined how various social environment characteristics are related to the suicide rate at the district-level, using nationwide longitudinal data over 11 years.

METHODS

We used the district-level age-standardized suicide rate and a total of 12 annual social environment characteristics that represented socioeconomic, demographic, urbanicity, general health behaviors, and other environmental characteristics from 229 administrative districts in South Korea. A Bayesian hierarchical model with integrated Laplace approximations (INLA) was used to examine the spatiotemporal association between the rate of suicide and the social environment indicators selected for the study.

RESULTS

In the total population, the indicators "% of population aged 65 and older eligible for the basic pension", "% vacant houses in the area", "% divorce", "% single elderly households", "% detached houses", "% current smokers", and "% of population with obesity" showed positive associations with the suicide rate. In contrast, "% of people who regularly participated in religious activities" showed negative associations with suicide rate. The associations between these social environment characteristics and suicide rate were generally more statistically significant in males and more urbanized areas, than in females and less urbanized areas; however, associations differed amongst age groups, depending on the social environment characteristic variable under study.

CONCLUSIONS

This study investigated the complex role of social environments on suicide rate in South Korea and revealed that higher suicide rates were associated with lower values of socioeconomic status, physical exercise, and religious activities, and with higher social isolation and smoking practice. Our results can be used in the development of targeted suicide prevention policies.

Changes in the pattern of suicide attempters visiting the emergency room after COVID-19 pandemic: an observational cross sectional study

BACKGROUND

This study aimed to find out the change in the rate and pattern of suicide attempts during severe acute respiratory syndrome COVID-19 pandemic period.

METHODS

This study was a retrospective analysis of data collected as a part of an emergency room-based post-suicide management program. The data were collected through interviews and from medical records of suicide attempts, maintained in the emergency room, from January 19 to October 31, 2020, during the "COVID-19 period," and those who attempted suicide from January 19 to October 31, 2019 "pre-COVID-19 period." We extracted educational background, marital status, occupation, presence of domestic partner, history of mental illness, alcohol consumption, history of previous suicide attempts; suicide attempt method and location (i.e., at home or a place other than home) at the time of attempt, and whether the attempt was a mass suicide. In addition, we compared patient severity between "COVID-19 period" and "pre-COVID-19 period" using the initial KTAS (South Korean triage and acuity scale) level, consciousness level, and systolic blood pressure. In 2012, KTAS was developed through the Ministry of Health and Welfare's research project to establish triage system in South Korea.

RESULTS

The analysis of the number of suicide attempts during "pre-COVID-19 period" and " COVID-19 period" showed that the number of suicide attempts during "COVID-19 period" (n = 440) increased compared to the "pre-COVID-19 period" (n = 400). Moreover, the method of suicide attempts during "COVID-19 period" included overdose of drugs such as hypnotics, antipsychotics, and pesticides that were already possessed by the patient increased compared to the "pre-COVID-19 period" (P < 0.05). At the time of the visit to the emergency room, high KTAS level, low level of consciousness, and low systolic blood pressure, were observed, which were significantly different between "COVID-19 period" and "pre-COVID-19 period" (P < 0.05).

CONCLUSION

With the worldwide COVID-19 virus spread, suicide rate and suicide attempts at home have significantly increased. In addition, patient severity was higher in the "COVID-19 period" than that in the "pre-COVID-19 period." The increasing suicide attempt rate should be controlled by cooperation between the emergency room and regional organizations.

Comparison of the factors for suicidal ideation and suicide attempt: a comprehensive examination of stress, view of life, mental health, and alcohol use

This study was performed to examine the elements that cause suicidal ideation to develop into a suicide attempt by comparing the factors related to suicidal ideation and attempt. The subjects in the study were 5982 employees, who received mental health screening from January 2016 to December 2019 in Korea. Multivariate binary logistic regression analysis was performed with suicidal ideation and suicide attempt as dependent variables respectively. While suicidal ideation was associated with both moderate and severe grades of depression and alcohol consumption, only severe grades of depression and alcohol consumption were associated with suicide attempts. Among family, interpersonal, work-related, and financial stress, which were significant predictors of suicidal ideation, only family stress predicted suicide attempts. Whereas dissatisfaction with the present, regret for the past, and hopelessness for the future were all predictors for suicidal ideation, only regret for the past was a significant predictor of suicide attempts. The distinctive impact of family stress on suicide attempts suggests that family support can play a pivotal role in suicide prevention, and the significant impact of regret for the past on suicide attempts indicates the need for a cognitive approach in a high-risk population. Finally, the substantial impact of alcohol on suicide attempts compared to suicidal ideation suggests the importance of alcohol regulation in suicide prevention.

Suicide rates by occupation in Korea, 1993-2017: the impacts of financial crisis and suicide policy

This study compared the suicide rates among different groups of occupations in Korea and their changes from 1993 through 2017. The suicide rate tended to be low in the high skill occupations except the manager group. The suicide rates showed increases around the financial crises of 1997 and 2008 in most occupations, and the sharpest increase was observed in the managers. The suicide rate in the manager group, which was the lowest among all occupation groups until the mid 2000s, showed the sharpest increase and became the highest since 2012 among all occupation groups. The sustained reduction in suicide rates among the skilled agricultural, forestry and fishery workers in Korea, following the implementation of paraquat control since 2005, shows that means restriction is an effective and essential way for reducing suicides. While more efforts should be put into means restriction, policy makers should focus on changing public perceptions of suicide in order that it would not be accepted as a possible solution for the difficulties in life.

Building the Nation: The Success and Crisis of Korean Civil Religion

Civil religion refers to a country’s beliefs, symbols, and rituals that bolster national unity and strengthen its citizens’ sense of identity and belonging. However, the literature on civil religion is divided between those who attribute it to bottom-up cultural spontaneity and those who see it as an ideological top-down construction. Moreover, there has been a relative lack of scholarly attention to Korean civil religion. This paper addresses both issues by arguing that a strong civil religion indeed exists in the country and that it has been an important part of the “nation-building” process since the founding of the Republic of Korea in 1948. The paper highlights how a succession of authoritarian regimes (1948–1987) successfully mobilized a strong civil religion for political purposes. The resulting civil religion targeted economic growth as the national goal to overcome all social ills, focused on the country’s ethnic and cultural homogeneity to boost national confidence and pride, exalted its traditional religions, especially Confucianism, as repositories of Korean traditional culture, and rendered sacred meanings to national symbols such as the flag and national anthem. Even after democratization, Korean civil religion remains largely ideological, as the Korean government is heavily involved in framing, planning, sponsoring, and promoting the country’s civil religion. Nevertheless, the paper concludes by observing that this civil religion is entering a period of crisis due to political fragmentation among Korean elites and deeply rooted cultural and societal change.

Alcohol consumption and suicide rate: A cross-sectional analysis in 183 countries

The age-standardized suicide rate and per capita alcohol consumption from 183 countries were acquired, and its relationship with per capita alcohol consumption was examined by the regression analysis. The positive associations between per capita alcohol consumption and the suicide rate were found among males and females in all income groups of countries. Compared with other environmental factors, controlling alcohol consumption has a distinct target and can be feasible and effective for reducing suicides. Health policy makers should keep in mind that alcohol consumption is costing lives not just by long-term physical ailments but also by making people vulnerable to suicide.

Prediction of suicide among 372,813 individuals under medical check-up

BACKGROUND

Suicide is a serious social and public health problem. Social stigma and prejudice reduce the accessibility of mental health care services for high-risk groups, resulting in them not receiving interventions and committing suicide. A suicide prediction model is necessary to identify high-risk groups in the general population.

METHODS

We used national medical check-up data from 2009 to 2015 in Korea. The latest medical check-up data for each subject was set as an index point. Analysis was undertaken for an overall follow-up period (index point to the final tracking period) as well as for a one-year follow-up period. The training set was cross-validated fivefold. The predictive model was trained using a random forest algorithm, and its performance was measured using a separate test set not included in the training.

RESULTS

The analysis covered 372,813 individuals, with an average (SD) overall follow-up duration of 1.52 (1.52) years. When we predicted suicide during the overall follow-up period, the area under the receiver operating characteristic curve (AUC) was 0.849, sensitivity was 0.817, and specificity was 0.754. The performance of the predicted suicide risk model for one year from the index point was AUC 0.818, sensitivity 0.788, and specificity 0.657.

CONCLUSIONS

This is probably the first suicide predictive model using machine learning based on medical check-up data from the general population. It could be used to screen high-risk suicidal groups from the population through routine medical check-ups. Future studies may test preventive interventions such as exercise and alcohol in these high-risk groups.