The incidence of stroke by socioeconomic status, age, sex, and stroke subtype: a nationwide study in Korea

Associations between socioeconomic status and stroke in American adults: A population-based study

Stroke is an acute cerebrovascular disease that can lead to disability and death. This study aimed to investigate the relationship between socioeconomic status (SES) and stroke. SES was evaluated by two variables: poverty to income ratio (PIR) and education level. In this multi-subject study, we collected data from the National Health and Nutrition Examination Survey (NHANES) database between 2009 and 2018, and finally 22,792 adults (≥20 years old) were included in the study. We proceeded with weighted multivariate logistic regression analysis as well as subgroup analysis. When analyzing the effect of PIR on stroke alone, the results showed that an increase in PIR levels was associated with a decrease in stroke incidence (OR = 0.764 95% CI: (0.711, 0.820), p < 0.001). The multivariate analysis presented a decline in stroke incidence in the highest quartile PIR group compared to the lowest quartile PIR group (OR = 0.296 95% CI: (0.214, 0.409), P＜0.001). Our results indicated that PIR is a protective factor for stroke, but there are exceptions in this relationship among different people. Hence, it is imperative that policymakers, healthcare providers, and clinicians take into account the inequality distribution of SES among adults while developing and executing stroke prevention and treatment strategies.

Exploring the bidirectional causal link between household income status and genetic susceptibility to neurological diseases: findings from a Mendelian randomization study

Objectives

Observational studies have revealed that socioeconomic status is associated with neurological disorders and aging. However, the potential causal effect between the two remains unclear. We therefore aimed to investigate the causal relationship between household income status and genetic susceptibility to neurological diseases using a bidirectional Mendelian randomization (MR) study.

Methods

An MR study was conducted on a large-sample cohort of the European population pulled from a publicly available genome-wide association study dataset, using a random-effects inverse-variance weighting model as the main standard. MR-Egger regression, weighted median, and maximum likelihood estimation were also performed concurrently as supplements. A sensitivity analysis, consisting of a heterogeneity test and horizontal pleiotropy test, was performed using Cochran's Q, MR-Egger intercept, and MR-PRESSO tests to ensure the reliability of the conclusion.

Results

The results suggested that higher household income tended to lower the risk of genetic susceptibility to Alzheimer's disease (odds ratio [OR]: 0.740, 95% confidence interval [CI] = 0.559-0.980, p-value = 0.036) and ischemic stroke (OR: 0.801, 95% CI = 0.662-0.968, p-value = 0.022). By contrast, higher household income tended to increase the risk of genetic susceptibility to Parkinson's disease (OR: 2.605, 95% CI = 1.413-4.802, p-value = 0.002). No associations were evident for intracranial hemorrhage (OR: 1.002, 95% CI = 0.607-1.653, p-value = 0.993), cerebral aneurysm (OR: 0.597, 95% CI = 0.243-1.465, p-value = 0.260), subarachnoid hemorrhage (OR: 1.474, 95% CI = 0.699-3.110, p-value = 0.308), or epilepsy (OR: 1.029, 95% CI = 0.662-1.600, p-value = 0.899). The reverse MR study suggested no reverse causal relationship between neurological disorders and household income status. A sensitivity analysis verified the reliability of the results.

Conclusion

Our results revealed that the populations with a superior household income exhibit an increased predisposition of genetic susceptibility to Parkinson's Disease, while demonstrating a potential decreased genetic susceptibility to ischemic stroke and Alzheimer's disease.

The relationship of income on stroke incidence in Finland and China

BACKGROUND

Stroke incidence has continued to increase recently in most countries. The roles of individual-level income on the incidence of overall stroke and its subtypes are still unknown, especially in low- and middle-income countries and the cross-national evidence is also limited. We explored the association between individual-level income and stroke incidence in Finland and China.

METHODS

Changde Social Health Insurance Database (N=571 843) and Finnish population register (N=4 046 205) data were used to calculate standard stroke incidence rates, which were employed to assess the absolute incidence difference between income quintiles. Cox regression was used to compare income differences in first-ever stroke incidence.

RESULTS

The highest income quintile had lower overall and subtype stroke incidence when compared to lower-income quintiles. The relative difference was more evident in hemorrhagic stroke incidence. After adjusting for age and employment status, the disparity of stroke incidence between the lowest and highest income quintiles was high among both men and women and in Finland and China. The disparity was particularly notable among men: in Finland, the hazard ratio (HR) for hemorrhagic stroke was 0.633 [95% confidence interval (95% CI) 0.576-0.696] and HR 0.572 (95% CI 0.540-0.606) for ischemic stroke. The respective figures were HR 0.452 (95% CI 0.276-0.739) and HR 0.633 (95% CI 0.406-0.708) for China.

CONCLUSIONS

Individual-level income is related to overall and subtype stroke incidence. Future studies should explore the causal relationship between individual-level income and stroke incidence.

Temporal trend of first-ever ischaemic stroke incidence from 2010 to 2019 in South Korea: a nationwide retrospective cohort study

OBJECTIVE

Ischaemic stroke incidence is on the decline globally, but the trend in South Korea is unknown. In this study, the 10-year incidence trends of first-ever ischaemic stroke in South Korea were evaluated.

DESIGN, SETTING AND PARTICIPANTS

The National Health Insurance Services medical claim data were used to construct 10 annual cohorts of adults aged 20 years and older, who had not been diagnosed with stroke, to find out the incidence trends of first-ever ischaemic stroke from 2010 to 2019.

OUTCOME MEASURES

The primary outcomes were crude and age-adjusted incidence rates for 10 years. Crude incidence rates of the age groups and incidence age statistics were calculated. For comparison among the income groups, age-adjusted incidence rates were used. Incidence rates in all the groups were analysed separately by sex.

RESULTS

Age-standardised incidence rates of ischaemic stroke per 100 000 were 101.0 in men, and 67.6 in women in 2010; and 92.2 in men, and 55.0 in women in 2019. By age group, there was a decrease in women over 40 years of age, and men over 60 years of age. The relative difference in stroke incidence rates between medical aid beneficiaries and the highest income group increased from 1.5 to 1.87 over 10 years.

CONCLUSIONS

Age-standardised incidence rate of ischaemic stroke has decreased from 2010 to 2019 for both man and women. The incidence rate was stable in the younger age groups and decreased in the older age groups, and the disparities between income groups have widened over the past decade. Stroke prevention strategies are needed for the younger age group and the low-income group. Further research is needed to study the risk factors contributing to the incidence of ischaemic stroke in different groups.

Effect of income level on stroke incidence and the mediated effect of simultaneous diagnosis of metabolic syndrome diseases; a nationwide cohort study in South Korea

BACKGROUND

This study aimed to determine whether a simultaneous diagnosis of main components of metabolic syndrome (MetS) (hypertension, diabetes mellitus, and dyslipidemia) plays a mediator between income level and stroke.

METHODS

We used the National Health Insurance Service National Sample Cohort database from 2006 to 2015. The mediator variables were the number of main MetS components diagnosed simultaneously (two or more/three or more). We used a weighting approach method of causal mediation analysis to apply counterfactual frameworks to the Cox proportional hazards regression model.

RESULTS

A total of 213,526 people were included with 1,690,665.3 person-years of followed up. Compared with the high-income group, the risk of being diagnosed with two or more components of MetS significantly increased in all other income groups [middle-income OR 1.05 (95% CI 1.02-1.08); low-income OR 1.09 (95% CI 1.05-1.12); Medical Aid beneficiaries OR 1.39 (95% CI 1.32-1.47)]. A lower level of income was significantly associated with a higher risk of stroke compared with the high-income group [middle-income HR 1.15 (95% CI 1.07-1.25); low-income HR 1.19 (95% CI 1.10-1.29); Medical Aid beneficiaries HR 1.63 (95% CI 1.48-1.80)]. In the Medical Aid beneficiaries, simultaneous diagnosis of the main metabolic components acted as a significant mediator between income levels and stroke incidence, with 26.6% mediated when diagnosed with two or more diseases and 21.1% when diagnosed with all three.

CONCLUSIONS

Co-diagnosis of MetS components played a significant mediator role between income level and stroke incidence.

Socioeconomic status and lifestyle in young ischaemic stroke patients: a possible relationship to stroke recovery and risk of recurrent event

OBJECTIVES

Socioeconomic status (SES) and lifestyle have impact on recovery after ischaemic stroke (IS) and on risk of recurrent ischaemic stroke (RIS) in elderly patients. With regard to currently available limited data on young people, we aimed to assess SES and parameters of lifestyle and evaluate their relationship to stroke recovery and risk of RIS in young patients.

METHODS

We analysed consecutive young IS patients < 50 years enrolled in the prospective HISTORY (Heart and Ischaemic STrOke Relationship studY) study registered on ClinicalTrials.gov (NCT01541163). Data were acquired from structured a self-evaluating multiple-choice questionnaire. Clinical outcome was assessed using the Modified Rankin Scale (MRS) after 3 months with score 0-1 for excellent outcome.

RESULTS

Data were obtained from 297 (163 males, mean age 39.6 ± 7.8 years) young patients. Patients with MRS 0-1 (237, 79.8%) did not differ in SES except university education (21.1 vs. 3.3%; p = 0.001), less smoked (16.5 vs. 58.3%; p < 0.001), more of them did regular sport activities (79.1 vs. 51.6%; p = 0.02) and passed regular preventive medical checks (45.6 vs. 24.2%; p = 0.01). Twelve (4%) patients suffered from RIS during a follow-up with median of 25 months. They did not differ in SES but had higher body mass index (31.6 vs. 26.7; p = 0.007), reported less regular sport activities (16.7 vs. 73.0%; p < 0.001) and less regular medical checks (8.3 vs. 40.0%; p = 0.001).

CONCLUSION

In young patients, SES had no relationship to clinical outcome after IS and to risk of RIS except education level. Some parameters of health lifestyle were presented more in patients with excellent outcome and without RIS during the follow-up.

A cohort study on the relationship between education level and high-risk population of stroke

Objective

To explore the relationship between education level and high-risk population among stroke screening populations in Zunyi City, China.

Methods

The cluster sampling method was adopted to collect the medical history, laboratory examinations and physical examinations for the permanent residents of Zunyi City, Guizhou Province. Taking education level as a key socioeconomic status (SES) indicator, multivariate logistic regression analysis was used to evaluate the risk factors of high-risk groups with different education levels.

Results

Among the included 4149 subjects, 494 were in the high-risk group and 3655 were in the non-high-risk group. The proportion of the high-risk population with education level ≥ high secondary school (8.7%) was significantly higher than that of the low-risk population. After adjusting for age, gender, and BMI, the OR of those with education leve l ≥ high secondary school was 2.8 (95% CI 1.9-4.2), which was significantly higher than those with education level of illiterate/primary school. In the model adjusted for all confounding factors, compared with illiterate/primary school, people with education level ≥ high secondary school were more likely to be at high risk of stroke (OR 3.0, 95% CI 1.9-4.6).

Conclusion

Education level ≥ high secondary school is an independent influencing factor for the high-risk population of stroke in Zunyi, which may be related to smoking and lipid metabolism abnormalities of people with high education level. Key interventions for high-risk populations with high education levels may have positive significance in reducing the incidence of stroke.

The Contribution of Material, Behavioral, Psychological, and Social-Relational Factors to Income-Related Disparities in Cardiovascular Risk Among Older Adults

Supplemental digital content is available in the text.

Understanding the factors underlying health disparities is vital to developing strategies to improve health equity in old age. Such efforts should be encouraged in Korea.

Epidemiology of cardiovascular disease and its risk factors in Korea

Cardiovascular disease (CVD) is the leading cause of death and a major contributor to disability worldwide. Currently, Korea is among countries with the lowest CVD mortality rates, and the age-adjusted CVD mortality rate is still decreasing. However, depending on the CVD type, the mortality and incidence trends vary. Without age-standardization, cerebrovascular disease mortality peaked in 1994 (82.1 per 100K) and continued to decline until 2018 (44.7 per 100K), while heart disease mortality recorded the lowest level in 2001 (44.9 per 100K) then increased again until 2018 (74.5 per 100K). Age-standardized mortality rates showed different trends: both cerebrovascular disease and heart disease mortality rates have declined over the past few decades, although the rate of decline varies. Based on the National Health Insurance claim database, the numbers of hospitalization for cerebrovascular disease and ischemic heart disease are increasing, but the age-standardized hospitalization rates are decreasing. Unlike other types of CVDs, heart failure is rapidly increasing in both mortality and hospitalization rates regardless of age-standardization. Seventy percent of Korean adults have at least one risk factor, 41% have ≥ 2 risk factors, and 19% have ≥ 3 risk factors including hypertension, diabetes, hypercholesterolemia, obesity, and smoking. Exposure to multiple risk factors increases with age, with 65% of senior citizens over 70 having ≥ 2 risk factors and 34% having ≥ 3 risk factors. As the elderly population, especially those with multiple risk factors and chronic disorders, is increasing, the management of this high-risk group will be an important challenge to prevent CVD in Korea.

Korea Heart Disease Fact Sheet 2020: Analysis of Nationwide Data

BACKGROUND AND OBJECTIVES

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. To provide an overview of the temporal trends in the burden of CVD, the Korean Society of Cardiology has published the Korea Heart Disease Fact Sheet in 2020.

METHODS

We analyzed anonymized data of the Causes of Death Statistics, National Health Insurance Claims Database, and Korea National Health and Nutrition Examination Survey to assess mortality, hospitalizations, and risk factors for CVD.

RESULTS

The CVD mortality decreased until 2010, then steadily increased up to 123 per 100,000 persons in 2018. Since 2002, the number and rate of CVD hospitalization have continued to grow. In 2018, approximately 12.1 million Korean adults had hypertension, 4.3 million had diabetes, 8.7 million had hypercholesterolemia, 14.9 million had obesity, and 8.8 million were currently smoking. The number of risk factors increased markedly with older age; 58.4% of adults age ≥70 years had ≥2 risk factors.

CONCLUSIONS

CVD mortality and hospitalization have gradually increased in the last decade, and a substantially high proportion of adults were carrying more than 1 cardiovascular risk factor in 2018. With the rapid population aging, a continued increase in CVD appears inevitable in Korea. Concerted and sustained approaches are essential to achieve early prevention and reduce the burden of CVD.

Risk of major bleeding by ethnicity and socioeconomic deprivation among 488,107 people in primary care: a cohort study

BACKGROUND

Antithrombotic medications (antiplatelets and anticoagulants) reduce the risk of cardiovascular disease (CVD), but with the disadvantage of increasing bleeding risk. Ethnicity and socioeconomic deprivation are independent predictors of major bleeds among patients without CVD, but it is unclear whether they are also predictors of major bleeds among patients with CVD or atrial fibrillation (AF) after adjustment for clinical variables.

METHODS

Prospective cohort study of 488,107 people in New Zealand Primary Care (including 64,420 Māori, the indigenous people of New Zealand) aged 30-79 years who had their CVD risk assessed between 2007 and 2016. Participants were divided into three mutually exclusive subgroups: (1) AF with or without CVD (n = 15,212), (2) CVD and no AF (n = 43,790), (3) no CVD or AF (n = 429,105). Adjusted hazards ratios (adjHRs) were estimated from Cox proportional hazards models predicting major bleeding risk for each of the three subgroups to determine whether ethnicity and socioeconomic deprivation are independent predictors of major bleeds in different cardiovascular risk groups.

RESULTS

In all three subgroups (AF, CVD, no CVD/AF), Māori (adjHR 1.63 [1.39-1.91], 1.24 [1.09-1.42], 1.57 [95% CI 1.45-1.70], respectively), Pacific people (adjHR 1.90 [1.58-2.28], 1.30 [1.12-1.51], 1.62 [95% CI 1.49-1.75], respectively) and Chinese people (adjHR 1.53 [1.08-2.16], 1.15 [0.90-1.47], 1.13 [95% CI 1.01-1.26], respectively) were at increased risk of a major bleed compared to Europeans, although for Chinese people the effect did not reach statistical significance in the CVD subgroup. Compared to Europeans, Māori and Pacific peoples were generally at increased risk of all bleed types (gastrointestinal, intracranial and other bleeds). An increased risk of intracranial bleeds was observed among Chinese and Other Asian people and, in the CVD and no CVD/AF subgroups, among Indian people. Increasing socioeconomic deprivation was also associated with increased risk of a major bleed in all three subgroups (adjHR 1.07 [1.02-1.12], 1.07 [1.03-1.10], 1.10 [95% CI 1.08-1.12], respectively, for each increase in socioeconomic deprivation quintile).

CONCLUSION

Ethnicity and socioeconomic status should be considered in bleeding risk assessments to guide the use of antithrombotic medication for the management of AF and CVD.

Sex-based differences in and risk factors for metabolic syndrome in adults aged 40 years and above in Northeast China: Results from the cross-sectional China national stroke screening survey

OBJECTIVES

Low levels of income and education are risk factors for metabolic syndrome in the population of Northeast China, which has a high incidence of metabolic syndrome and cardiovascular diseases. This study aimed to determine sex-based differences associated with the prevalence of and risk factors for metabolic syndrome among people older than 40 years in Northeast China; this has not been previously investigated.

DESIGN

This study analysed a portion of the large sample data of the national cross-sectional screening of China from 2016. Metabolic syndrome was defined as the presence of any three of the following five risk factors: abnormal waist circumference; high levels of triglycerides, high-density lipoprotein cholesterol or fasting plasma glucose; and elevated blood pressure. Multiple regression analysis was used to investigate sex-based differences in the prevalence of, and risk factors for metabolic syndrome.

SETTING

The study was conducted in Dehui City, Jilin Province, China.

PARTICIPANTS

A total of 4052 participants with complete questionnaire information and laboratory examination results were included.

RESULTS

The prevalence of metabolic syndrome was 50.1% overall (38.4% in men and 57.9% in women; p<0.001). High body mass index and hip circumference were associated with metabolic syndrome in both sexes. In addition, physical inactivity (OR and 95% CI 1.44 (1.06 to 1.97); p=0.022) in men and advanced age (OR and 95% CI 1.54 (1.15 to 2.04); p=0.003) in women were factors associated with metabolic syndrome. Women with junior high school education or above and living in rural areas were less likely to have metabolic syndrome. For men, education and rural or urban living had no association with metabolic syndrome.

CONCLUSIONS

The risk factors for metabolic syndrome have similarities and differences in different sexes; thus, the prevention and treatment of metabolic syndrome should be based on these sex differences.

Association Between Carbon Monoxide Intoxication and Incidence of Ischemic Stroke: A Retrospective Nested Case-Control Study in South Korea

OBJECTIVES

Severe neurological sequelae occur in patients with carbon monoxide (CO) intoxication; however, whether the latter increases the long-term risk of developing ischemic stroke is unclear. We investigated the association between CO intoxication and ischemic stroke using data from the Korean National Health Information Database.

MATERIALS AND METHODS

We performed a retrospective, nested case-control study of 27,984 individuals treated for CO intoxication and 27,984 sex- and age-matched controls. Initially, we calculated the overall incidence and hazard ratio (HR) of ischemic stroke using conditional logistic regression. Thereafter, we calculated the incidences and HRs according to covariates and follow-up periods.

RESULTS

The CO intoxication group had a significantly higher risk of developing ischemic stroke than the control group (adjusted HR 2.31, 95% CI [confidence interval] = 2.01-2.65). Male sex (adjusted HR 2.73, 95% CI = 2.23-3.34), age <40 (adjusted HR 3.53, 95% CI = 2.15-5.82), low income (adjusted HR 2.55, 95% CI = 1.56-4.15), comorbidities (adjusted HR 2.59, 95% CI = 1.48-4.52), and current smokers (adjusted HR 3.55, 95% CI = 1.67-7.60) had a higher risk of ischemic stroke. The risk of ischemic stroke was highest within 2 years after CO intoxication (adjusted HR 7.47, 95% CI = 2.76-20.26), and even >6 years after, the risk remained significantly higher than in the control group (adjusted HR 1.84, 95% CI = 1.53-2.20).

CONCLUSIONS

CO intoxication and the long-term risk of ischemic stroke are associated.

Lifetime risks and health impacts of hemorrhagic and ischemic stroke in South Korea

This study is aimed toward estimating the lifetime risks, life expectancy, expected years of life lost (EYLL), and lifetime costs related to different subtypes of stroke in South Korea. We included 13,994 patients diagnosed with stroke (ICD-10, I60-I63) in the National Health Insurance Service-National Sample Cohort of Korea between 2006 and 2015. Lifetime risks were calculated using the cumulative incidence rate for patients aged 18–84. Lifetime survival data were obtained through the Kaplan–Meier method and extrapolated with a rolling-over extrapolation algorithm. The lifetime costs were estimated by multiplying the average monthly expenditures with the survival probabilities and adding the values over lifetime. The lifetime risks of stroke in Korea have been decreasing consistently over the last decade with the exception of subarachnoid hemorrhage in females, which appears to have slightly increased. The EYLL is higher in hemorrhagic stroke than in ischemic stroke (6–9.7 vs. 4.7). Expected lifetime costs reimbursed by the NHIS would amount to about $71,406 accompanied with $14,921 copayment from the patients for hemorrhagic stroke, and $50,551 and $11,666, respectively, for ischemic stroke. Further studies are warranted to combine survival with quality of life and functional disability to obtain a more detailed outcome assessment of the potential impact of the prevention of stroke.

Association between socioeconomic status and incident stroke in China

Background

Little is known about the impact of socioeconomic status (SES) on incidence of stroke in China. This study aimed to examine the association of SES, which was measured by different indicators, with incidence of stroke and gender differences in the association.

Methods and results

Two prospective cohort studies were conducted including 2852 participants aged ≥60 years in Anhui province and 3016 participants in four other provinces in China. During a median follow-up of 7.1 years, 211 incident stroke cases occurred in the Anhui cohort. The risk of stroke increased with living in rural areas (adjusted HR 2.49, 95% CI 1.19 to 5.22; women 3.64, 95% CI 1.17 to 11.32, men 2.23, 95% CI 0.81 to 6.19), but not significantly with educational level, occupational class, satisfactory income and financial problems (except for women with low education). The four-province cohort had 113 incident stroke cases over the 3.1 years’ follow-up. The five SES indicators were not significantly associated with incident stroke (except for increased risk in men with high occupation), but additional measurement for actual income showed that incident stroke increased in women with low personal income and in men with high family income. Pooled data from the two cohorts demonstrated the impacts of rural living (1.66, 95% CI 1.08 to 2.57) and having high occupational class (1.56, 95% CI 1.01 to 2.38), and gender differences for women with low education (2.26, 95% CI 1.19 to 4.27).

Conclusions

Rural living and being female with low SES are associated with increased stroke risk in China. Strategies to improve public health in the rural communities and gender-specific targets for health inequality should be an integral component of stroke interventions.

Comparing Activity and Participation between Acquired Brain Injury and Spinal-Cord Injury in Community-Dwelling People with Severe Disability Using WHODAS 2.0

Central-nervous-system (CNS) injuries constitute a significant cause of morbidity (often resulting in long-term disability) and mortality. This cross-sectional study compared the activity and participation of community-dwelling people with severe disability from acquired brain injuries (ABI) (n = 322) and spinal-cord injuries (SCI) (n = 183) to identify risk factors related to disability. Data were collected through a questionnaire survey of community-dwelling people with severe disability attending 65 healthcare centers. The survey included the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) and sociodemographic factors. We categorized a registered grade of disability of 1 or 2 as severe disability. WHODAS 2.0 domain and summary scores were compared between the ABI and SCI groups, and risk factors associated with disability were identified through regression analysis. ABI participants had significantly higher disability in cognition and relationships, whereas patients with SCI had higher disability in mobility (p < 0.05). Onset duration was negatively correlated with cognition, relationships, participation, and summary scores in ABI participants (p < 0.05). Neither group’s socioeconomic factors were associated with WHODA 2.0 scores. Understanding the different patterns of disability between SCI and ABI in community-dwelling people with severe disability helps establish future plans for the management of health resources.

Measurement of Socioeconomic Position in Research on Cardiovascular Health Disparities in Korea: A Systematic Review

OBJECTIVES

The validity of instruments measuring socioeconomic position (SEP) has been a major area of concern in research on cardiovascular health disparities. The purpose of this systematic review is to identify the current status of the methods used to measure SEP in research on cardiovascular health disparities in Korea and to provide directions for future research.

METHODS

Relevant articles were obtained through electronic database searches with manual searches of reference lists and no restriction on the date of publication. SEP indicators were categorized into compositional, contextual, composite, and life-course measures.

RESULTS

Forty-eight studies published from 2003 to 2018 satisfied the review criteria. Studies utilizing compositional measures mainly relied on a limited number of SEP parameters. In addition, these measures hardly addressed the time-varying and subjective features of SEP. Finding valid contextual measures at the organizational, community, and societal levels that are appropriate to Korea's context remains a challenge, and these are rarely modeled simultaneously. Studies have rarely focused on composite and life-course measures.

CONCLUSIONS

Future studies should develop and utilize valid compositional and contextual measures and appraise social patterns that vary across time, place, and culture using such measures. Studies should also consider multilevel influences, adding a focus on the interactions between different levels of intertwined SEP factors to advance the design of research. More attention should be given to composite and life-course measures.

Factors influencing return to work after stroke: the Korean Stroke Cohort for Functioning and Rehabilitation (KOSCO) Study

OBJECTIVE

To investigate the rate of return to work and identify key factors associated with return to work between 3 months and 2 years after stroke.

DESIGN

Prospective cohort study.

SETTING

The Korean Stroke Cohort for Functioning and Rehabilitation (KOSCO) in Korea.

PARTICIPANTS

A total of 193 persons with first-ever stroke who reported working status at 3 months after stroke.

OUTCOME MEASURES

Data on baseline characteristics were collected from medical records. Functional assessments were performed using the National Institutes of Health Stroke Scale, the modified Rankin Scale, the Fugl-Meyer Assessment, the Functional Ambulatory Category, the Korean Mini-Mental State Examination, the Korean version of the Frenchay Aphasia Screening Test, the American Speech-Language-Hearing Association National Outcomes Measurement System, the Korean-Modified Barthel Index, the Geriatric Depression Scale-Short Form and the EuroQol-5 dimensions. An enumeration survey included the Reintegration to Normal Living Index, the Psychosocial Well-being Index-Short Form (, the Family Support Index and the Caregivers Burden Index.

RESULTS

Overall, 145 (75.1%) patients who had a stroke in the "Continuously-Employed" group and 48 (24.9%) in the "Employed-Unemployed" group returned to work between 3 months and 2 years after stroke. Multivariate logistic analysis demonstrated that in patients who had a stroke, characteristics such as age, PWI-SF Score, and caregiver characteristics, including age, sex (female) and living arrangements, were significantly associated with return to work between 3 months and 2 years after stroke.

CONCLUSION

Age and PWI-SF Score of patients who had a stroke, as well as the age, sex and living arrangements of caregivers, are key factors influencing the return to work after stroke.

TRIAL REGISTRATION NUMBER

NCT03402451.

Is androgen deprivation therapy associated with cerebral infarction in patients with prostate cancer? A Korean nationwide population-based propensity score matching study

Purpose

Previous studies have suggested that androgen deprivation therapy (ADT) is associated with cerebral infarction. However, conflicting results have been reported by other researchers. The aim of this study was to evaluate the association between ADT and cerebral infarction in patients with prostate cancer (PC) using big data.

Materials and Methods

Using information from the National Health Insurance Service database representative of the entire Korean adult PC population (n = 206 735), data regarding ADT and cerebral infarction between 2009 and 2016 were analyzed. Adjusted hazard ratios for cerebral infarction associated with ADT were estimated using propensity score‐matched Cox proportional hazards models and Kaplan‐Meier survival analyses.

Results

The final cohort comprised 36 146 individuals with PC, including 24 069 men (66.6%) who underwent ADT. During the mean follow‐up of 4.1 years, 2792 patients were newly diagnosed with cerebral infarction. In the unmatched cohort, there was a significant difference in the annual incidence of cerebral infarction between the ADT and non‐ADT groups (22.8 vs 14.6 per 1000 person‐years, respectively). However, there was no significant difference between the ADT and non‐ADT groups in the matched cohort (14.9 vs 14.6 per 1000 person‐years). The adjusted hazard ratio for cerebral infarction for PC patients who underwent ADT was 1.045 (95% CI 0.943‐1.159; P = 0.401) compared with those who did not undergo ADT. In addition, the cumulative duration of ADT was also not associated with an increased risk for cerebral infarction. However, older age, hypertension, diabetes, myocardial infarction, congestive heart failure, peripheral vascular disease, renal disease, dementia, and atrial fibrillation were revealed to be factors contributing to cerebral infarction.

Conclusion

This nationwide population‐based study revealed that ADT was not associated with cerebral infarction after adjusting for potential confounders.

Effects of socioeconomic status on risk of ischemic stroke: a case-control study in the Guangzhou population

BACKGROUND

The association between socioeconomic status (SES) and stroke risk remains controversial around the world. It is not clear that the effect of SES on stroke in China due to the lack of relevant research. We aimed to assess the association between SES and risks of first-ever ischemic stroke in Guangzhou, China.

METHODS

Cases were recruited from neurology department in the First Affiliated Hospital of Guangdong Pharmaceutical University during September 2016-October 2017. Age- and sex-matched controls were derived from surgical departments, over the same period. SES was assessed based on education, occupation, and income. Education was divided into ≤6 years, 6-9 years, 10-12 years, and > 12 years. Family monthly income per capita was categorized into ≤¥1000, ¥1001-3000, ¥3001-5000, and > ¥5001. Occupation was stratified into manual, non-manual, no job, and retired. A multivariate logistic regression model was used to determine the association between SES and risk of ischemic stroke.

RESULTS

In total, 347 ischemic stroke patients and 347 controls were recruited, with mean ages of 60.54 ± 13.13 and 60.56 ± 13.07 years, respectively. After adjusting for confounding factors, odds ratio (OR) for 6-9 years of education was 2.63 (95% confidence interval [CI] 1.45-4.75); > 12 years, 2.18 (1.25-3.82) compared with those for < 6 years of education. ORs for the second lowest, third lowest, and highest incomes were 1.96 (1.21-3.15), 4.16 (2.39-7.22), and 2.83(1.25-6.39), respectively, compared with those for the lowest income. ORs for manual workers and non-manual workers were 1.95 (1.23-3.07) and 1.87 (1.05-3.33), compared with individuals without jobs.

CONCLUSIONS

Higher SES is positively related with risks of ischemic stroke, explained by cardiovascular diseases and unhealthy lifestyles in Guangzhou, China. Thus, effective strategies such as extensive health education, promoting a healthy lifestyle, screening for risk factors to prevent stroke should be implemented to reduce ischemic stroke incidences among the high SES group.

Temporal trends in educational inequalities in non-communicable diseases in Korea, 2007-2015

Background

Socioeconomic inequalities in non-communicable diseases are known to exist; however there is a paucity of research describing the secular trends in these inequalities. To this end, the current study aims to explore the recent time trends in social patterning of selected non-communicable diseases among Korean adults between 2007 and 2015.

Methods

Using data from the Korea National Health and Nutrition Examination Survey (KNHANES), temporal trends in socioeconomic inequalities in diabetes, arthritis, asthma and depressive symptoms were assessed across three time points. Respondents were adults aged 20 years or over (N = 47,091, 20,180 men and 26,911 women). Socioeconomic circumstance was assessed based on highest level of educational attainment. We estimated prevalence ratios with 95% confidence intervals using Poisson regression with robust variance estimation (adjusted for age, smoking status, alcohol consumption, obesity, and physical activity) separately for men and women. The magnitude of the inequalities was computed using the relative index of inequality (RII).

Results

In men, diabetes was not associated with educational attainment, while there was evidence of a negative association in women across surveys. Similar inverse associations were found with arthritis and depressive symptoms, but these associations were less clear for asthma. RII showed a non-significant increasing trend in educational disparities in depressive symptoms. Meanwhile, relative inequalities in diabetes, arthritis and asthma have narrowed. These trends were, in general, more pronounced in women.

Conclusions

The findings of this study indicate higher burden of selected NCDs among the lower educational groups, particularly among women. In addition, our results indicated some improvements in inequalities in diabetes, arthritis and asthma in recent years. These findings have important implications for understanding the causes of social patterning of NCDs and for the targeting of effective interventions.

The Impact of the Financial Crisis on Lifestyle Health Determinants Among Older Adults Living in the Mediterranean Region: The Multinational MEDIS Study (2005-2015)

Objectives

By the end of the 2000s, the economic situation in many European countries started to deteriorate, generating financial uncertainty, social insecurity and worse health status. The aim of the present study was to investigate how the recent financial crisis has affected the lifestyle health determinants and behaviours of older adults living in the Mediterranean islands.

Methods

From 2005 to 2015, a population-based, multi-stage convenience sampling method was used to voluntarily enrol 2749 older adults (50% men) from 20 Mediterranean islands and the rural area of the Mani peninsula. Lifestyle status was evaluated as the cumulative score of four components (range, 0 to 6), that is, smoking habits, diet quality (MedDietScore), depression status (Geriatric Depression Scale) and physical activity.

Results

Older Mediterranean people enrolled in the study from 2009 onwards showed social isolation and increased smoking, were more prone to depressive symptoms, and adopted less healthy dietary habits, as compared to their counterparts participating earlier in the study (p<0.05), irrespective of age, gender, several clinical characteristics, or socioeconomic status of the participants (an almost 50% adjusted increase in the lifestyle score from before 2009 to after 2009, p<0.001).

Conclusions

A shift towards less healthy behaviours was noticeable after the economic crisis had commenced. Public health interventions should focus on older adults, particularly of lower socioeconomic levels, in order to effectively reduce the burden of cardiometabolic disease at the population level.

Selected Food Consumption Mediates the Association between Education Level and Metabolic Syndrome in Korean Adults

Background/Aims: Low socioeconomic status (SES) is linked to higher incidence/mortality of cardiovascular disease, but emerging evidence inconsistently reported that education level, a proxy for SES, is related to cardiovascular risk and metabolic syndrome (MetS) in Koreans. Furthermore, limited information is available on whether dietary components would mediate the relationship between education level and cardiovascular risk. We hypothesized that selected food consumption mediates the association between education level and MetS prevalence. Methods: Data from the Korea National Health and Nutritional Examination Survey (2008-2011) were included in cross-sectional analyses (n = 11,029, 30-64 years). The possible mediating effect of selected food groups (fruits, raw vegetables, red meat, milk, and soft drinks) on the association between education level and MetS was tested using a multiple mediation model. Results: Education level was negatively associated with MetS prevalence. The association between lower education level and higher MetS prevalence was partially mediated by selected food consumption (lower intakes of fruit, red meat and milk; higher intakes of vegetable and soft drink) after adjusted for covariates. Gender also modified the association between education level and MetS prevalence that was more prominent in women than in men. Conclusions: Selected food consumption substantially contributes to the association between education level and MetS in Korean adults, especially among women.

Promoter Polymorphism (-174, G/C) of Interleukin-6 and Arterial Thromboembolic Events: A Meta-Analysis

Background

Ischemic stroke and myocardial infarction are fatal diseases and are among the top 10 causes of death in Korea, including arterial thromboembolic events. Many previous studies have described the function of interleukin-6 (IL-6) in arterial thromboembolic events and the association between promoter single-nucleotide polymorphism (SNP) (rs1800795; −174, G/C) of the IL-6 gene. However, these results were controversial. Therefore, we performed a meta-analysis to more precisely assess the association between the SNP of the IL-6 gene and susceptibility to arterial thromboembolic events.

Material/Methods

We used PubMed, Embase, Google Scholar, and Korean Studies Information Service System (KISS) electronic databases. Comprehensive Meta-analysis software (Corporation, NJ) was used to evaluate the relationship between rs1800795 SNP of IL-6 gene and risk of arterial thromboembolic events. Odds ratio (OR), 95% confidence interval (CI), and P value were also calculated. The 13 eligible studies were analyzed in the meta-analysis.

Results

The present meta-analysis found that rs1800795 SNP of IL-6 gene is not significantly associated with susceptibility to arterial thromboembolic events (C allele vs. G allele, OR=1.04, 95% CI=0.91–1.19, P=0.619; CC vs. CG+GG, OR=1.09, 95% CI=0.91–1.31, P=0.364; CC+CG vs. GG, OR=0.97, 95% CI=0.78–1.21, P=0.763, respectively), and the SNP of IL-6 gene also did not show any significant association with ischemic stroke or myocardial infarction (P>0.05 in each model).

Conclusions

We found that rs1800795 SNP of IL-6 gene was not related to arterial thromboembolic events. However, further study will be needed to confirm these results.

The effects of socioeconomic status on stroke risk and outcomes

The latest evidence on socioeconomic status and stroke shows that stroke not only disproportionately affects low-income and middle-income countries, but also socioeconomically deprived populations within high-income countries. These disparities are reflected not only in risk of stroke but also in short-term and long-term outcomes after stroke. Increased average levels of conventional risk factors (eg, hypertension, hyperlipidaemia, excessive alcohol intake, smoking, obesity, and sedentary lifestyle) in populations with low socioeconomic status account for about half of these effects. In many countries, evidence shows that people with lower socioeconomic status are less likely to receive good-quality acute hospital and rehabilitation care than people with higher socioeconomic status. For clinical practice, better implementation of well established treatments, effective management of risk factors, and equity of access to high-quality acute stroke care and rehabilitation will probably reduce inequality substantially. Overcoming barriers and adapting evidence-based interventions to different countries and health-care settings remains a research priority.