Efflux-linked accelerated evolution of antibiotic resistance at a population edge.

Efflux is a common mechanism of resistance to antibiotics. We show that efflux itself promotes accumulation of antibiotic-resistance mutations (ARMs). This phenomenon was initially discovered in a bacterial swarm where the linked phenotypes of high efflux and high mutation frequencies spatially segregated to the edge, driven there by motility. We have uncovered and validated a global regulatory network connecting high efflux to downregulation of specific DNA-repair pathways even in non-swarming states. The efflux-DNA repair link was corroborated in a clinical "resistome" database: genomes with mutations that increase efflux exhibit a significant increase in ARMs. Accordingly, efflux inhibitors decreased evolvability to antibiotic resistance. Swarms also revealed how bacterial populations serve as a reservoir of ARMs even in the absence of antibiotic selection pressure. High efflux at the edge births mutants that, despite compromised fitness, survive there because of reduced competition. This finding is relevant to biofilms where efflux activity is high.

Loss-of-Function Mutations in epaR Confer Resistance to ϕNPV1 Infection in Enterococcus faecalis OG1RF.

Enterococcus faecalis is a Gram-positive opportunistic pathogen that inhabits the human gastrointestinal tract. Because of the high frequency of antibiotic resistance among Enterococcus clinical isolates, interest in using phage to treat enterococcal infections and to decolonize high-risk patients for antibiotic-resistant Enterococcus is rising. Bacteria can evolve phage resistance, but there is little published information on these mechanisms in E. faecalis In this report, we identified genetic determinants of E. faecalis resistance to phage NPV1 (ϕNPV1). We found that loss-of-function mutations in epaR confer ϕNPV1 resistance by blocking phage adsorption. We attribute the inability of the phage to adsorb to the modification or loss of an extracellular polymer in strains with inactivated epaR Phage-resistant epaR mutants exhibited increased daptomycin and osmotic stress susceptibilities. Our results demonstrate that in vitro spontaneous resistance to ϕNPV1 comes at a cost in E. faecalis OG1RF.

Goodbye PAM: Phage λ's Red recombination system cripples PAMs and helps dodge CRISPR attacks.

Ever wondered how the phage λ Red recombination system resembles the Red Queen? Hossain et al. (2021) provide an answer in this issue of Cell Host & Microbe. They show that Red debilitates PAM sequences by mutagenic repair of CRISPR-targeted DNA breaks in infecting λ, thus shaping the phage-CRISPR arms race.

Occupational inequalities in mortality in Korea: an analysis using nationally representative mortality follow-up data from the late 2000s and after / 한국역학회지

Many Korean and international studies have found higher mortality rates and poorer health conditions among manual workers than among non-manual workers. However, a recent study using unlinked data argued that since the economic crisis in Korea in the late 2000s, the mortality estimates of male Korean non-manual workers have been higher than those of manual workers. Our work using individually linked data from the late 2000s and after aimed to examine mortality inequality by occupational class. We analyzed Korea National Health and Nutrition Examination Survey data that were individually linked to cause-of-death data. Cox regression analysis was used to identify the hazard ratios for mortality by occupational class. Of 11,766 males aged between 35 and 64, 397 died between 2007 and 2018: 142 died from cancer, 68 from cardiovascular disease, 88 from external causes, and 99 from other causes. After controlling for age, the mortality estimates for manual workers were 1.85 times higher than those for upper non-manual workers (p<0.05). We observed no evidence of reversed mortality inequality among occupational classes in Korea since the 2000s; this previously reported finding might have been due to numerator-denominator bias arising from the use of unlinked data.

The Unequal Burden of Self-Reported Musculoskeletal Pains Among South Korean and European Employees Based on Age, Gender, and Employment Status

Background@#The objective of this study was to elucidate the relationships musculoskeletal pains with combined vulnerability in terms of age, gender, and employment status @*Methods@#The fifth European Working Conditions Survey (EWCS) in 2010 (43,816 participants aged 15 years and over) analyzed for European employees and the third Korean Working Conditions Survey (KWCS) in 2011 (50,032 participants aged 15 years and older) analyzed for Korean employees. In this study, three well known vulnerable factors to musculoskeletal pains (older age, female gender, and precarious employment status) were combined and defined as combined vulnerability. Associations of musculoskeletal pains with combined vulnerability were assessed with prevalence ratios (PRs) and 95% confidence intervals (CIs) estimated by Poisson regression models with robust estimates of variance. @*Results@#The prevalences of musculoskeletal pains were lower but the absolute and relative differences between combined vulnerabilities were higher among Korean employees compared with the European employees. Furthermore, the increased risk of having musculoskeletal pains according to combined vulnerability was modestly explained by socioeconomic factors and exposure to ergonomic risk factors, especially in Republic of Korea. @*Conclusions@#The results of this study showed that the labor market may be more unfavorable for female and elderly workers in Republic of Korea. Any prevention strategies to ward off musculoskeletal pains, therefore, should be found and implemented to mitigate or buffer against the most vulnerable work population, older, female, and precarious employment status, in Republic of Korea.

The Unequal Burden of Self-Reported Musculoskeletal Pains Among South Korean and European Employees Based on Age, Gender, and Employment Status

Background@#The objective of this study was to elucidate the relationships musculoskeletal pains with combined vulnerability in terms of age, gender, and employment status @*Methods@#The fifth European Working Conditions Survey (EWCS) in 2010 (43,816 participants aged 15 years and over) analyzed for European employees and the third Korean Working Conditions Survey (KWCS) in 2011 (50,032 participants aged 15 years and older) analyzed for Korean employees. In this study, three well known vulnerable factors to musculoskeletal pains (older age, female gender, and precarious employment status) were combined and defined as combined vulnerability. Associations of musculoskeletal pains with combined vulnerability were assessed with prevalence ratios (PRs) and 95% confidence intervals (CIs) estimated by Poisson regression models with robust estimates of variance. @*Results@#The prevalences of musculoskeletal pains were lower but the absolute and relative differences between combined vulnerabilities were higher among Korean employees compared with the European employees. Furthermore, the increased risk of having musculoskeletal pains according to combined vulnerability was modestly explained by socioeconomic factors and exposure to ergonomic risk factors, especially in Republic of Korea. @*Conclusions@#The results of this study showed that the labor market may be more unfavorable for female and elderly workers in Republic of Korea. Any prevention strategies to ward off musculoskeletal pains, therefore, should be found and implemented to mitigate or buffer against the most vulnerable work population, older, female, and precarious employment status, in Republic of Korea.

Edinburgh Postnatal Depression Scale used in South Korea

Background@#The Edinburgh Postnatal Depression Scale (EPDS), a validated screening tool for prenatal and postnatal depression, was included as a reimbursable item by the National Health Insurance Service of Korea in 2020. However, multiple Korean versions of the EPDS are used for public health programs and research. This study aimed to summarize the use of this scale in Korea and evaluate the distribution of validities, depression scores, and prevalence of depression according to Korean versions of the EPDS. @*Methods@#Korean versions of the EPDS most frequently used in public health policies and programs were summarized through internet searches using snowball strategy. A systematic literature review was conducted to evaluate the prenatal and postnatal depression scores and prevalence of depression measured using different Korean versions of the scale. @*Results@#We identified four Korean versions of the EPDS that are commonly used in public health programs and research. Among them, published evidence regarding validity and reliability was available for two versions. A review of 19 papers that assessed prenatal and postnatal depression using these versions showed large heterogeneity in scores and the prevalence of depression. @*Conclusion@#When measuring prenatal and postnatal depression using the EPDS, characteristics of the scale must be considered when interpreting results. A standardized Korean version of the EPDS needs to be developed by comparing the validity and reliability of different Korean versions. A field manual for screening should also be developed and distributed.

Spatio-temporal Analysis of Districtlevel Life Expectancy from 2004 to 2017 in Korea

Background@#Health indicators, such as mortality rates or life expectancy, need to be presented at the local level to improve the health of local residents and to reduce health inequality across geographic areas. The aim of this study was to estimate life expectancy at the district level in Korea through a spatio-temporal analysis. @*Methods@#Spatio-temporal models were applied to the National Health Information Database of the National Health Insurance Service to estimate the mortality rates for 19 age groups in 250 districts from 2004 to 2017 by gender in Korea. Annual district-level life tables by gender were constructed using the estimated mortality rates, and then annual district-level life expectancy by gender was estimated using the life table method and the Kannisto-Thatcher method. The annual district-level life expectancies based on the spatio-temporal models were compared to the life expectancies calculated under the assumption that the mortality rates in these 250 districts are independent from one another. @*Results@#In 2017, district-level life expectancy at birth ranged from 75.5 years (95% credible interval [CI], 74.0–77.0 years) to 84.2 years (95% CI, 83.4–85.0 years) for men and from 83.9 years (95% CI, 83.2–84.6 years) to 88.2 years (95% CI, 87.3–89.1 years) for women.Between 2004 and 2017, district-level life expectancy at birth increased by 4.57 years (95% CI, 4.49–4.65 years) for men and by 4.06 years (95% CI, 3.99–4.12 years) for women. To obtain stable annual life expectancy estimates at the district level, it is recommended to use the life expectancy based on spatio-temporal models instead of calculating life expectancy using observed mortality. @*Conclusion@#In this study, we estimated the annual district-level life expectancy from 2004 to 2017 in Korea by gender using a spatio-temporal model. Local governments could use annual district-level life expectancy estimates as a performance indicator of health policies to improve the health of local residents. The approach to district-level analysis with spatiotemporal modeling employed in this study could be used in future analyses to produce district-level health-related indicators in Korea.

Cancer-free Life Expectancy in Small Administrative Areas in Korea and Its Associations with Regional Health Insurance Premiums

Background@#To determine the priorities and resource allocation of community cancerrelated health policies, it is necessary to measure cancer-related health indicators and the burden of cancer by region. This study calculated the cancer-free life expectancy at the eup/ myeon/dong level (small administrative units in South Korea) for the first time, and analyzed its association with regional health insurance premiums. @*Methods@#We used aggregate data from the 2008–2017 National Health Information Database provided by the National Health Insurance Service. Cancer-free life expectancy was calculated by applying Sullivan's method to mortality and cancer prevalence by age group and sex for the 10-year period in 3,396 eups/myeons/dongs. Correlation analyses were performed to analyze the relationship between cancer-free life expectancy and regional health insurance premiums. @*Results@#Cancer-free life expectancy in eups/myeons/dongs of metropolitan areas tended to be higher than in non-metropolitan areas. However, some eups/myeons/dongs of non-metropolitan areas showed quite a high cancer-free life expectancy, especially for females. The median values of differences between cancer-free life expectancy and life expectancy at the eup/myeon/ dong level (total: 1.6 years, male: 1.8 years, female: 1.4 years) indicated that a person's healthy life can be shortened by a number of years due to cancer. The association of cancer-free life expectancy by eup/myeon/dong with the regional health insurance premium was statistically significant (β = 1.0, P < 0.001) and more prominent for males (β = 1.3, P < 0.001) than for females (β = 0.5, P < 0.001). The relationship between the regional health insurance premium and the burden of cancer (life expectancy minus cancer-free life expectancy) was also statistically significant (β = 0.2 for the total population, β = 0.2 for males, and β = 0.1 for females, all P values < 0.001). @*Conclusion@#This study showed a significant regional gap with regard to cancer-free life expectancy and the burden of cancer at the eup/myeon/dong level. This work makes a meaningful contribution by presenting new and firsthand summary measures of cancerrelated health across small areas in Korea. The results will also help the authorities to evaluate the effectiveness of local cancer management projects in small administrative areas and determine regional priorities for implementing cancer control policies.

Inequalities in Longitudinal Health Trajectories in Middle to Later Life: a Comparison of European Countries and Korea

Background@#This study compared inequalities in the longitudinal trajectory of health measured by latent growth curves (LGCs) in Korea and six other developed European countries. @*Methods@#Unconditional and conditional LGCs were fitted, with standardized self-rated health (SRH) as the outcome variable. Two nationally-representative longitudinal datasets were used: the Survey of Health, Aging and Retirement in Europe (2007-2015; 2,761 Swedish, 2,546 Danish, 2,580 German, 2,860 French, 2,372 Spanish, and 2,924 Italian respondents) and the Korean Longitudinal Study of Aging (2006–2014; 8,465 Korean respondents). @*Results@#The unconditional patterns of SRH trajectory were similar and unfavorable for women across the countries. Social factors such as education and income generally exerted a significant impact on health trends among older adults. Korea showed less favorable results for the disadvantaged than the advantaged as compared with Denmark, Germany, and France, which was consistent with theoretical expectations. In contrast, the relative SRH trajectory of the disadvantaged as against the advantaged was better as compared with Sweden and worse as compared with Spain/Italy, which was inconsistent with theories that would predict Korea's results were worse than Sweden and similar to Spain/Italy. Women had good SRH trajectory in Denmark and poorer SRH trajectory in Spain, Italy, and Korea, which were consistent. However, women in Sweden showed poorer and mixed outcome, which does not correspond to theoretical predictions. @*Conclusion@#These findings suggest that it is inconclusive whether Sweden and Denmark (with the most generous welfare arrangements) have better trajectories of health, and Spain, Italy, and Korea (with the least advanced state policies) have worse SRH paths among older adults. However, it can be inferred that Korean governmental policies may have produced a relatively worse context for the less-educated than the six European countries, as well as poorer settings for women than Denmark in terms of their initial SRH status.

Life Expectancy and Inequalities Therein by Income From 2016 to 2018 Across the 253 Electoral Constituencies of the National Assembly of the Korea / 예방의학회지

Objectives@#We calculated life expectancy and inequalities therein by income for the period of 2016-2018 across the 253 electoral constituencies of the 20th National Assembly election in Korea. @*Methods@#We obtained population and death data between 2016 and 2018 from the National Health Information Database and constructed abridged life tables using standard life table procedures according to gender and income quintiles for the electoral constituencies of the 20th National Assembly election held in 2016. @*Results@#Life expectancy across the 253 constituencies ranged from 80.51 years to 87.05 years, corresponding to a gap of 6.54 years. The life expectancy difference by income across the 253 constituencies ranged from 2.94 years to 10.67 years. In each province, the difference in life expectancy by income across electoral constituencies was generally greater than the inter-constituency differences. Constituencies in capital and metropolitan areas showed a higher life expectancy and a lower life expectancy difference by income than constituencies in rural areas. @*Conclusions@#Pro-rich inequalities in life expectancy by income existed in every electoral constituency in Korea. Both intra-constituency and inter-constituency socioeconomic inequalities in health should be highlighted in future policy-making in the National Assembly.

Inequality in Life Expectancy in Korea according to Various Categorizations of the National Health Insurance Premiums as a Marker of Income

The purpose of this study was to examine the degree to which the magnitude of income inequality in life expectancy according to different categorization across beneficiary types under the National Health Insurance Service (NHIS) in Korea. We used population and death data in 2017 from the National Health Information Database of the NHIS. Income quintile groups were classified in four ways according to beneficiary type (employee insured, self-employed insured, and Medical Aid beneficiaries). Standard life table procedures were used to calculate life expectancy. The life expectancy gap between the lowest and highest income quintiles was the largest when the entire population was divided into quintiles without distinguishing among types of beneficiaries. In conclusion, we suggest that income quintile indicators in NHIS data, measured without distinguishing among types of beneficiaries, may best represent the magnitude of health inequalities in Korean society. This indicator could be used for future research on health inequalities, as well as for monitoring health inequalities in Korea.

Life Expectancy in Areas around Subway Stations in the Seoul Metropolitan Area in Korea, 2008–2017

Background@#This study aimed to calculate life expectancy in the areas around 614 subway stations on 23 subway lines in the Seoul metropolitan area of Korea from 2008 to 2017. @*Methods@#We used the National Health Information Database provided by the National Health Insurance Service, which covers the whole population of Korea. The analysis was conducted on the level of the smallest administrative units within a 200-m radius of each subway station. Life expectancy was calculated by constructing an abridged life table using the number of population and deaths in each area and 5-year age groups (0, 1–4, …, 85+) during the whole study period. @*Results@#The median life expectancy in the areas around 614 subway stations was 82.9 years (interquartile range, 2.2 years; minimum, 77.6 years; maximum, 87.4 years). The life expectancy of areas around subway stations located in Seoul was higher than those in Incheon and Gyeonggi-do, but variation within the region was observed. Significant differences were observed between some adjacent subway stations. In Incheon and Gyeonggi-do, substantially higher life expectancy was found around subway stations in newly developed urban areas, and lower life expectancy was found in central Incheon and suburbs in Gyeonggi-do. @*Conclusion@#When using areas around subway stations as the unit of analysis, variation in life expectancy in the Seoul metropolitan area was observed. This approach may reduce the stigma associated with presenting health inequalities at the level of the smallest administrative units and foster public awareness of health inequalities.

Mediation effect of herpes zoster derived by statin use on cardiovascular disease risk

Background/Aims@#Although statins are widely used to reduce the risk of cardiovascular disease (CVD) including stroke and myocardial infarction (MI), it is reported that statin use increases the incidence of herpes zoster (HZ) that is associated with increased risk of CVD. So, we evaluated the mediation effect of HZ caused by statin use on CVD. @*Methods@#We analyzed a prospective cohort from the National Health Insurance Service-database of South Korea. All individuals received a medical check-up and were followed-up from 2002 to 2013. @*Results@#A total of 275,382 individuals > 40 years old were followed up for 11 years from 2003. Of these, 11,415 people (4%) were classified as statin users and 263,967 (96%) as non-statin users. Those who used statins had significantly lower risks of cardiovascular events, stroke, and MI compared with non-statin users; the adjusted hazard ratios in the multivariate analysis were 0.90 (95% confidence interval [CI], 0.82 to 0.98), 0.88 (95% CI, 0.80 to 0.98), and 0.91 (95% CI, 0.79 to 1.07), respectively. When we calculated the mediating effect of cardiovascular events by statin use through HZ, 11.6% of the total beneficial effect of cardiovascular events by statin use was mitigated through the occurrence of HZ caused by statin use. This mediating effect was higher in the younger age group (< 60 years). @*Conclusions@#This study showed that statin use reduced CVD by 10%, but the protective effect of statin use against CVD was mitigated by approximately 10% through the development of HZ caused by statin use.

Activated neural stem cells contribute to stroke-induced neurogenesis and neuroblast migration toward the infarct boundary in adult rats.

Stroke increases neurogenesis. The authors investigated whether neural stem cells or progenitor cells in the adult subventricular zone (SVZ) of rats contribute to stroke-induced increase in neurogenesis. After induction of stroke in rats, the numbers of cells immunoreactive to doublecortin, a marker for immature neurons, increased in the ipsilateral SVZ and striatum. Infusion of an antimitotic agent (cytosine-beta-D-arabiofuranoside, Ara-C) onto the ipsilateral cortex eliminated more than 98% of actively proliferating cells in the SVZ and doublecortin-positive cells in the ipsilateral striatum. However, doublecortin-positive cells rapidly replenished after antimitotic agent depletion of actively proliferating cells. Depleting the numbers of actively proliferating cells in vivo had no effect on the numbers of neurospheres formed in vitro, yet the numbers of neurospheres derived from stroke rats significantly (P<0.05) increased. Neurospheres derived from stroke rats self-renewed and differentiated into neurons and glia. In addition, doublecortin-positive cells generated in the SVZ migrated in a chainlike structure toward ischemic striatum. These findings indicate that in the adult stroke brain, increases in recruitment of neural stem cells contribute to stroke-induced neurogenesis, and that newly generated neurons migrate from the SVZ to the ischemic striatum.

Post-radiation dedifferentiation of meningioma into osteosarcoma.

BACKGROUND: A number of osteoblastic meningiomas, primary osteosarcomas of the meninges, and post-radiation osteosarcomas of the head have been reported. However, postradiation dedifferentiation of meningioma into osteosarcoma has not been reported previously. CASE PRESENTATION: In 1987 a caucasian man, then 38 years old, presented with a pituitary macroadenoma. He underwent a subtotal resection of the tumor and did well until 1990 when a recurrent tumor was diagnosed. This was treated with subtotal resection of the tumor, followed by radiation therapy for six weeks to a total of 54 Gy. He was considered "disease-free" for nearly ten years. However, most recently in July 2000, he presented with a visual field deficit due to a second recurrence of his pituitary macroadenoma, now with suprasellar extension. At this time, as an incidental finding, a mass attached to the dura was noted in the left parietal hemisphere. This dura-based mass had grown rapidly by January 2001 and was excised. It showed histological, immunohistochemical, and electron microscopic features of malignant meningioma and osteosarcoma with a sharp demarcation between the two components. CONCLUSIONS: We report a rare case of a radiation induced dedifferentiation of meningioma into osteosarcoma, which has not been reported previously.

Lateral supratentorial endodermal cyst: case report and review of literature.

OBJECTIVE AND IMPORTANCE: Epithelial cysts of the central nervous system are unusual entities, with the majority reported to occur in the spinal canal. More unusual is the intracranial presentation, which shows a predilection for midline localization in the posterior fossa, brainstem, and suprasellar regions. This report discusses the differential diagnosis, pathogenesis, radiographic presentation, and therapeutic considerations of a laterally positioned cerebral convexity endodermal cyst. CLINICAL PRESENTATION: A 49-year-old right-handed man presented with approximately a 30-month history of short- and long-term memory difficulties. A magnetic resonance imaging study revealed a large, nonenhancing, extra-axial cystic lesion overlying the right lateral frontal convexity. INTERVENTION: A right frontoparietal craniotomy exposed a large extra-axial cyst with an opaque, yellowish-white membrane containing a mucoid fluid. Histological analysis disclosed a layer of unremarkable, ciliated columnar epithelium with a basement membrane that stained positive for cytokeratin, periodic acid-Schiff, and Alcian blue. No evidence of either a muscular or cartilaginous layer around the mucosa was present to further delineate neurenteric versus bronchogenic origin of the cyst. CONCLUSION: This case involved the occurrence of a solitary endodermal cyst as an extra-axial mass localized over the lateral frontal lobe. The lateral supratentorial localization of this lesion illustrates the need for consideration of the pathogenesis of this entity as well as its diagnostic differentiation from other cystic abnormalities in this region. A review of the histochemistry of endodermal, neuroepithelial, and other cerebral cysts is presented.

Focal cerebral ischemia in rats produced by intracarotid embolization with viscous silicone.

Many factors contribute to the severity of neuronal cell death and the functional outcome in stroke. We describe an embolic model of focal cerebral ischemia in the rat that does not require craniotomy and is compatible with continuous measurement of regional CBF using multichannel laser Doppler flow (LDF) technique. Either a 22 microliters (large lesion) or 11 microliters (small lesion) bolus of viscous silicone was injected cephalad into the internal carotid artery. Upon injection, LDF decreased abruptly, most severely in the parietal cortex (-74% +/- 5%) in the large lesion and in the occipital cortex (-69% +/- 10%) in the small lesion model. Over the first hour, post-embolization LDF improved in most areas (e.g. -48% +/- 9% parietal, large lesion) but declined in the small lesion group in the occipital region (-81% +/- 8%). CBF measured by [C]14-IAP autoradiography 1 h post-embolization in the large lesion model demonstrated near-hemispheric ischemia (70% of hemisphere) with sparing of cingulate cortex. Autoradiography demonstrated that ischemia in the small lesion was largely cortical. Light microscopy of brains embolized with 11 microliters of dyed silicone showed filling of pial vessels with no silicone in the Circle of Willis or parenchyma. No animals in the large lesion group survived 24 h. Thirteen of 15 animals in the small lesion group survived for two weeks with resolution of initial hemiplegia, ocular asymmetry and weight loss. Hematoxylin-eosin staining two weeks post-embolization showed signs of severe hypoxia and infarction. In conclusion, the intracarotid silicone embolization technique produces a titrable, reproducible permanent ischemic injury by blocking perfusion in the pial circulation, and is amenable to multisite monitoring with laser Doppler flowmetry. The smaller embolus produces cortical infarction with high rate of survival and neurological recovery.

Why is Life Expectancy in Busan Shorter than in Seoul? Age and Cause-Specific Contributions to the Difference in Life Expectancy between Two Cities

PURPOSE: Seoul and Busan are the two largest cities in Korea. However, life expectancy (LE) in Busan is shorter than in Seoul and among the total Korean population. This study was conducted to decompose age- and cause-specific contributions to the LE difference between Seoul and Busan. MATERIALS AND METHODS: We obtained population and mortality data for Seoul and Busan between 2015 and 2017 from Statistics Korea. We applied Arriaga's decomposition method to life table data to estimate age- and cause-specific contributions to the LE difference between Seoul and Busan. RESULTS: During 2015–2017, LE in Busan was shorter than in Seoul by 2.22 years. Roughly two-thirds of the LE gap between Seoul and Busan was due to excess mortality among elderly people in Busan. The ≥85 age group alone contributed to approximately 20% of the LE gap, while no meaningful contribution was made by the 1–24 age groups. Cardiovascular disease accounted for over 40% of the total LE gap between Seoul and Busan, and this factor was more prominent in women. The top 15 leading specific causes of deaths explained nearly the entire LE difference between Seoul and Busan. CONCLUSION: The difference in LE between Seoul and Busan was due to higher mortality rate in Busan than in Seoul, especially in the elderly population and from cardiovascular diseases. Information on age- and cause-specific contributions to the LE difference between Seoul and Busan may guide health policy-makers to plan strategies for reducing the gap in LE.

Why Do Japan and South Korea Record Very Low Levels of Perceived Health Despite Having Very High Life Expectancies?

Japan and Korea follow a unique trend in which, despite reporting two of the highest life expectancies (LEs) among the Organization for Economic Co-operation and Development (OECD) countries, the proportion of people with good self-rated health (SRH) is disproportionately low. We sought to explain this high-LE-low-SRH paradox by examining associations among LE, the prevalence of good SRH, and healthcare utilization. Our hypothesis was that countries with more frequent healthcare use would demonstrate poorer SRH and that SRH would not show a meaningful association with LE among developed countries. This study extracted data from Health at a Glance 2017 by the OECD for 26 countries with valid and comparable information on LE, SRH, and the number of doctor consultations per capita. Correlations among LE, good SRH, and number of doctor consultations per capita were analyzed. The number of annual doctor consultations per capita and the prevalence of good SRH were closely correlated (correlation coefficient=−0.610); excluding outliers produced a higher correlation coefficient (−0.839). Similar patterns were observed when we replaced good SRH with poor SRH. Meanwhile, the correlation coefficient between annual per capita doctor consultations and LE was quite low (−0.216). Although good SRH is closely related to better LE at the individual level, this was not true at the national level. Frequent use of healthcare in Japan and Korea was strongly correlated with poorer SRH, without any meaningful correlation with LE.