Combined effect of individual and neighborhood socioeconomic status on mortality in patients with newly diagnosed dyslipidemia: A nationwide Korean cohort study from 2002 to 2013

Trends in Regional Disparity in Cardiovascular Mortality in Korea, 1983–2019

Mortality from cardiovascular diseases (CVDs) had been significantly improved in several decades. However, the recent reduction was slowed down, and the burden remained high. Understanding regional disparity in cardiovascular deaths would help facilitate the improvement. Thus, we investigated geographic variation in CVD mortality and its spatiotemporal trend in Korea between 1983 and 2019. The findings showed higher mortality in the southeastern regions, while the regional disparity converged over time. It suggested that these regions call for action in terms of prevention and management of CVDs, in addition to an effort to reduce the death rates in other regions.

Background and Objectives

Despite remarkable reduction in cardiovascular disease (CVD) mortality, the burden has remained the leading cause of death. Since little research has focused on regional disparity in CVD mortality, this study aims to investigate its spatiotemporal trends in Korea from 1983 to 2019.

Methods

Using the causes of death statistics in Korea, we analyzed the geographic variation in deaths from CVDs from 1983 to 2019. The sex and age-standardized mortality rate was calculated according to the 17 administrative regions. The analyses include all diseases of the circulatory system (International Classification of Diseases-10 codes, I00–I99), along with the following 6 subcategories which were not mutually exclusive: total heart disease (I00–I13 and I20–I51), hypertensive heart disease (I10–I13), ischemic heart disease (I20–I25), myocardial infarction (I21–I23), heart failure (I50), and cerebrovascular disease (I60–I69).

Results

Overall, heart failure death rate increased across all regions, and other CVD death rates showed a decreasing trend. Regional disparity in mortality was substantial in the early 1980s but converged over time. In all types of cardiovascular mortality, Busan, Ulsan and Gyeongnam remained the highest, although they showed a downward trend like other regions. Jeju continued to have a relatively low CVD mortality rate.

Conclusions

The regional disparity substantially decreased compared to the 1980s. However, the relatively high burden of CVD mortality in the southeastern region has not been fully resolved.

Effects of diabetes mellitus on the rate of carpal tunnel release in patients with carpal tunnel syndrome

The objective of this study was to evaluate the effects of diabetes mellitus (DM) on the rate of carpal tunnel release (CTR) using a large nationwide cohort in Korea and to identify risk factors, including comorbidities and socioeconomic status (SES), associated with CTR. Patients with a primary or secondary diagnosis of carpal tunnel syndrome (CTS; ICD-10 code: G560) were selected and divided into two groups according to the presence of DM. A Cox proportional hazard model was used to assess the rate of CTR between the two groups. To evaluate the influence of demographic factors, comorbidities, and SES on CTR, multivariate Cox proportional hazard regression models were used to adjust for confounding variables. In total, 12,419 patients with CTS were included in the study: 2487 in DM cohort and 9932 in non-DM cohort. DM duration was negatively related with the rate of CTR (HR = 0.89, 95% CI 0.87–0.91) in CTS patients with DM. The rate of CTR was decreased in patients with DM compared to those without DM in the unadjusted model; however, after adjusting for comorbidities, DM had no significant effect on the rate of CTR. Female sex (HR = 1.50, 95% CI 1.36–1.67) correlated with the rate of CTR, and an inverse relationship between the number of comorbidities and CTR was found (p < 0.001) irrespective of DM. Diabetic polyneuropathy (DPN) was not associated with CTR, and we did not find any factors correlating with CTR in DPN patients. We found that CTS patients with more comorbidities or combined with a longer duration of DM were undertreated in real-word practice. Actual outcomes of CTR in CTS patents with various comorbidities should be investigated in future studies for optimal management of CTS.

Combined effects of individual and neighbourhood socioeconomic status on older adults' mortality: a retrospective follow-up study in Hong Kong

OBJECTIVES

This study examined the interaction effects of individual and neighbourhood socioeconomic status (SES) in older adults in Hong Kong, considering all-cause and cause-specific mortality from respiratory disease, cancer, cardiovascular diseases, ischaemic heart disease, stroke, nonmedical disease and suicide.

DESIGN

A retrospective follow-up study.

SETTING

Hong Kong Special Administrative Region, a rapidly ageing society with 16.1% residents aged 65 years or older in 2020.

PARTICIPANTS

43 910 people aged 65 years or older were enrolled at baseline. They had participated in health check-ups during 2000-2003 in one of the Elderly Health Centres. Observation periods started on the date of the participant's first health check-up, and ended at death, or 31 December 2011, whichever occurred first.

OUTCOME MEASURES

All-cause and cause-specific mortality over the study timeframe.

ANALYSIS

Cox's proportional hazards regression models were applied to estimate the adjusted HRs of mortality, by including covariates at neighbourhood (deprivation) and individual levels (poverty, education and type of housing).

RESULTS

The 'double tragedy theory' (ie, lower SES persons living in lower SES neighbourhoods have worst health outcomes) was more related to cancer, while the 'psychosocial comparison theory' (ie, lower SES persons living in higher SES neighbourhoods have poorer health outcomes) was more related to cardiovascular, ischaemic heart disease, and stroke.

CONCLUSION

There were important interaction effects between neighbourhood and individual factors on mortality. Policies based on the interaction between individual and neighbourhood SES should be considered. For instance, for cancer, targeted services (ie, free consultation, relevant treatment information, health check-up, etc) could be allocated in socioeconomically deprived areas to support individuals with low SES. On the other hand, more free public services to reduce psychological stresses (ie, psychological support services, recreational services, health knowledge information, etc) could be provided for those individuals with low SES living in higher SES areas to reduce stroke, cardiovascular and ischaemic heart diseases.

Metropolitan age-specific mortality trends at borough and neighborhood level: The case of Mexico City

Understanding the spatial and temporal patterns of mortality rates in a highly heterogeneous metropolis, is a matter of public policy interest. In this context, there is no, to the best of our knowledge, previous studies that correlate both spatio-temporal and age-specific mortality rates in Mexico City. Spatio-temporal Kriging modeling was used over five age-specific mortality rates (from the years 2000 to 2016 in Mexico City), to gain both spatial (borough and neighborhood) and temporal (year and trimester) data level description. Mortality age-specific patterns have been modeled using multilevel modeling for longitudinal data. Posterior tests were carried out to compare mortality averages between geo-spatial locations. Mortality correlation extends in all study groups for as long as 12 years and as far as 13.27 km. The highest mortality rate takes place in the Cuauhtémoc borough, the commercial, touristic and cultural core downtown of Mexico City. On the contrary, Tlalpan borough is the one with the lowest mortality rates in all the study groups. Post-productive mortality is the first age-specific cause of death, followed by infant, productive, pre-school and scholar groups. The combinations of spatio-temporal Kriging estimation and time-evolution linear mixed-effect models, allowed us to unveil relevant time and location trends that may be useful for public policy planning in Mexico City.

Nutrition Labeling Usage Influences Blood Markers in Body-Size Self-Conscious Individuals: The Korean National Health and Nutrition Examination Survey (KNHANES) 2013-2018

This study analyzed the effects of nutrition labeling and examined whether nutrition labeling usage influences the levels of blood markers, such as high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) in body-size self-conscious individuals. The dependent variables were HDL-C and TG; the independent variables were the respondents' awareness of nutrition labeling use, sociodemographic factors, perceived health status, stress, lifestyle, frequency of eating out, family history of hyperlipidemia, survey year, body mass index, total energy intake, and cholesterol levels. Body-size perception was assessed by matching body mass index with subjective body-shape recognition using data from the Korean National Health and Nutrition Examination Survey (2013-2018). Differences were observed in HDL-C and TG levels according to nutrition labeling usage and body-image perception. The group that recognized body image correctly showed high HDL-C and low TG levels when they actively used nutrition labeling, whereas the group that recognized body image incorrectly showed no significant changes in HDL-C and TG levels even when actively using nutrition labeling. The standard nutritional information, which does not consider individual body-size perceptions, has a restrictive effect. Policies should be developed towards tailored intervention strategies considering individual body-size perception.

The major effects of health-related quality of life on 5-year survival prediction among lung cancer survivors: applications of machine learning

The primary goal of this study was to evaluate the major roles of health-related quality of life (HRQOL) in a 5-year lung cancer survival prediction model using machine learning techniques (MLTs). The predictive performances of the models were compared with data from 809 survivors who underwent lung cancer surgery. Each of the modeling technique was applied to two feature sets: feature set 1 included clinical and sociodemographic variables, and feature set 2 added HRQOL factors to the variables from feature set 1. One of each developed prediction model was trained with the decision tree (DT), logistic regression (LR), bagging, random forest (RF), and adaptive boosting (AdaBoost) methods, and then, the best algorithm for modeling was determined. The models' performances were compared using fivefold cross-validation. For feature set 1, there were no significant differences in model accuracies (ranging from 0.647 to 0.713). Among the models in feature set 2, the AdaBoost and RF models outperformed the other prognostic models [area under the curve (AUC) = 0.850, 0.898, 0.981, 0.966, and 0.949 for the DT, LR, bagging, RF and AdaBoost models, respectively] in the test set. Overall, 5-year disease-free lung cancer survival prediction models with MLTs that included HRQOL as well as clinical variables improved predictive performance.

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.

Quantification of Risk Factors for Cervical Ossification of the Posterior Longitudinal Ligament in Korean Populations: A Nationwide Population-based Case-control Study

STUDY DESIGN

Case-control study.

OBJECTIVE

To quantify risk factors for cervical ossification of the posterior longitudinal ligament (OPLL) using a large nationwide cohort in Korea, a country with a high prevalence of OPLL.

SUMMARY OF BACKGROUND DATA

OPLL is a pathological calcification of the posterior longitudinal ligament of the spine. OPLL progression can cause spinal cord injury that results in disability. Considering neurologic deficits and disability caused by OPLL, identifying OPLL risk factors for early prediction have important health benefits.

METHODS

The nationwide population-based matched cohort study was conducted using the Korean National Health Insurance Service cohort data. We selected patients with a primary diagnosis of OPLL involving cervical lesion (International Classification of Diseases-10 code: M48.82, M48.83). A matched cohort without cervical OPLL was enrolled by randomly matching patients by sex, age, year of diagnosis, and residential area to the OPLL group with a ratio of 1:9. Logistic regression analyses were performed to identify risk associated with OPLL development using odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Comorbidities, such as hypertension (OR = 1.283, 95% CI 1.071-1.538), ischemic stroke (OR = 1.386, 95% CI 1.017-1.889), diabetes mellitus (OR = 1.331, 95% CI 1.098-1.615), hypothyroidism (OR = 1.562, 95% CI 1.165-2.094), and osteoporosis (OR = 1.456, 95% CI 1.151-1.842), were significantly associated with the prospective development of OPLL, with low predictive value.

CONCLUSION

OPLL was significantly associated with comorbidities such as hypertension, ischemic stroke diabetes mellitus, hypothyroidism, and osteoporosis. Our findings can provide helpful information for OPLL prediction and offer important health benefits.

LEVEL OF EVIDENCE

3.

Socioeconomic Status, Frailty, and All-Cause Mortality in Korean Older Adults: A 3-Year Population-Based Prospective Study

Background

Little is known regarding the effects of socioeconomic status (SES) and frailty on mortality in Korea.

Objective

This study investigated the combined impact of low SES and frailty on all-cause mortality in Korean older adults.

Methods

Study sample at baseline comprised 7,960 community-dwelling adults (56.8% women) aged 65 years and older. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of low SES and frailty for all-cause mortality.

Results

Overall, low SES plus frailty resulted in an increased risk of all-cause mortality (HR = 1.56, 95% CI = 1.09–2.23, P = 0.015) even after adjustments for all the measured covariates, as compared with high SES plus nonfrailty (HR = 1). Among older adults aged 65–75 years, the increased mortality risk of either low SES plus nonfrailty (HR = 1.37, 95% CI = 1.02–1.84, P = 0.038) or high SES plus frailty (HR = 2.09, 95% CI = 1.12–3.91, P = 0.021) remained significant even after adjustments for all the covariates, as compared with high SES plus nonfrailty (HR = 1).

Conclusion

The current findings suggest that either low SES or frailty is significantly associated with increased all-cause mortality in Korean older adults.

The association between socioeconomic status and visual impairments among primary glaucoma: the results from Nationwide Korean National Health Insurance Cohort from 2004 to 2013

Background

Glaucoma is one of the most leading causes of permanent visual impairments in Korea, and social expenses spent for the glaucoma are increasing. This study is to identify association between socioeconomic status and the visual impairments caused by primary glaucoma in Korea.

Methods

This study is based on a cohort study using stratified representative samples in the National Health Insurance claim data from 2002 to 2013 with 1,025,340 representative subjects. Target subjects were patients who are newly diagnosed with primary glaucoma from 2004 to 2013. We conducted a multiple logistic regression analysis depending on the occurrence of visual impairment and its temporal order compared to the glaucoma diagnosis.

Results

Among 1728 patients with primary glaucoma, those with low and middle income shows higher odds ratio (OR) of the visual impairments than those with high income group (low income; OR = 3.42, 95% Confidential Interval (CI):2.06–5.66, middle income; OR = 2.13, 95% CI: 1.28–3.55), in case of the occurrence of the visual impairments preceded the diagnosis of glaucoma.

Conclusions

Glaucoma patients without pre-existing glaucoma history before visual impairment have higher association between socioeconomic status and the occurrence of visual impairments by primary glaucoma. Since glaucoma had not been diagnosed and recognized yet, the differences may have been derived from the disparities of the awareness of the glaucoma. These findings call attention to the correlation between socioeconomic factors and the visual impairments by glaucoma, and raise public health needs over the importance of glaucoma awareness and eye screening for glaucoma, especially for low socioeconomic status.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-017-0551-y) contains supplementary material, which is available to authorized users.

Cross-level interaction between individual socioeconomic status and regional deprivation on overall survival after onset of ischemic stroke: National health insurance cohort sample data from 2002 to 2013

INTRODUCTION

The literature on stroke mortality and neighborhood effect is characterized by studies that are often Western society-oriented, with a lack of racial and cultural diversity. We estimated the effect of cross-level interaction between individual and regional socioeconomic status on the survival after onset of ischemic stroke.

METHODS

We selected newly diagnosed ischemic stroke patients from 2002 to 2013 using stratified representative sampling data of 1,025,340 subjects. A total of 37,044 patients over the 10 years from 2004 to 2013 had newly diagnosed stroke. We calculated hazard ratios (HR) of 12- and 36-month mortality using the Cox proportional hazard model, with the reference group as stroke patients with high income in advantaged regions.

RESULTS

For the middle income level, the patients in advantaged regions showed low HRs for overall mortality (12-month HR 1.27; 95% confidence interval [CI], 1.13-1.44; 36-month HR 1.25; 95% CI, 1.14-1.37) compared to the others in disadvantaged regions (12-month HR 1.36; 95% CI, 1.19-1.56; 36-month HR 1.30; 95% CI, 1.17-1.44). Interestingly, for the low income level, the patients in advantaged regions showed high HRs for overall mortality (12-month HR 1.27; 95% CI, 1.13-1.44; 36-month HR 1.33; 95% CI, 1.22-1.46) compared to the others in disadvantaged regions (12-month HR 1.25; 95% CI, 1.09-1.43; 36-month HR 1.30; 95% CI, 1.18-1.44).

CONCLUSION

Although we need to perform further investigations to determine the exact mechanisms, regional deprivation, as well as medical factors, might be associated with survival after onset of ischemic stroke in low-income patients.