Association of Primary Care Physician Supply with Population Mortality in South Korea: A Pooled Cross-Sectional Analysis

BACKGROUND

Primary care physicians perform a comprehensive role by providing continuous, patient-centered, and accessible healthcare and establishing connections with specialized care. However, the association between the supply of primary care physicians and mortality rates in South Korea has not been thoroughly investigated.

METHODS

This study utilized data from 229 si-gun-gu in South Korea from 2016 to 2020. The densities of primary care physicians, physicians in functional primary clinics, specialists in primary care facilities, and active physicians per 100,000 people were independent variables. Age-adjusted all-cause mortality and cause-specific mortality rates per 100,000 individuals were the dependent variables. Negative binomial regression, negative binomial regression with a pseudo-panel approach, and geographically weighted regression were used to analyze the data.

RESULTS

Our study revealed a significant negative association between the density of primary care physicians and all-cause mortality. An increase in a primary care physician per 100,000 population was significantly linked to a 0.11% reduction in all-cause mortality (incidence rate ratio, 0.9989; 95% confidence interval, 0.9983-0.9995). Similar associations have been observed between mortality rates owing to cardiovascular diseases, respiratory tract diseases, and traffic accidents.

CONCLUSION

This study provides evidence that having a higher number of primary care physicians in South Korea is associated with lower mortality rates. Future research should consider better indicators that reflect the quality of primary care to better understand its impact on population health outcomes. These findings emphasize the significance of strengthening primary care in the South Korean healthcare system to improve the overall health and wellbeing.

Differential Oxidative Stress Responses in Type II Airway Epithelial Cells Impact Premature Senescence and Lung Fibrosis Susceptibility

PURPOSE/OBJECTIVE(S)

Radiation-Induced Pulmonary Fibrosis (RIPF) is a late toxicity characterized by premature senescence in Type II airway epithelial cells (AECII) and accumulation of alternatively activated (M2) macrophages. Differential susceptibility to RIPF is observed across mouse strains. Based on our prior study of the effects of macrophage variation on RIPF, we hypothesized that intrinsic differences in AECII oxidative stress response across mouse strains also impact susceptibility to RIPF.

MATERIALS/METHODS

Ten-week-old female mice from C57L, C57BL6 and C3H/HeN strains were exposed to thoracic irradiation (5x6 Gy, n>5 per group). Fifteen weeks after radiation, lung tissue was collected and examined with Masson-Trichrome staining (histologic changes) and β-galactosidase activity assay (senescence). AECII prepared from mice of each strain were exposed to irradiation. To assess differential gene expression, total RNA was extracted and assessed with a multiplex analysis platform and quantitative PCR. Senescence was assessed by β-galactosidase activity assay in primary AECII after irradiation or after co-culture with M2 macrophages polarized with IL13.

RESULTS

Susceptibility to radiation-induced lung injury, survival, and premature AECII senescence vary by mouse strain: C57L (fibrosis-prone), C57BL6J (-intermediate) and C3H/HeN (-resistant). Enriched AECII from each strain exhibited differential expression of genes related to inflammatory responses including SASP production after irradiation. Minimal increased expression of Il1r1 was observed in irradiated and unirradiated AECII from C3H/HeN, however Il1rn levels were markedly elevated in response to irradiation. The expression of Thioredoxin (Txn) and Thioredoxin reductase 1 (Txnrd1) in AECII from C3H/HeN was significantly higher than those observed in other strains. In Vivo, C3H/HeN mouse lungs exhibited the least premature senescence in AECII after irradiation. Premature senescence in AECII irradiated In Vitro or co-cultured with superoxide anion-producing M2 macrophages was substantially less in AECII from C3H/HeN compared to other strains.

CONCLUSION

A comparison of primary AECII from three different mouse strains identified intrinsic differences in expression of major inflammatory signaling (IL1R and IL1RN) and redox homeostasis status (TXN and TXNDR1) molecules. This study is the first to demonstrate that intrinsic differences in AECII impacts susceptibility to premature senescence and lung fibrosis after irradiation.

Has South Korea achieved the goals of national health insurance? Trends in financial protection of households between 2011 and 2018

This study aims to investigate the evolution of financial protection of households against OOP in South Korea, where subsequent policies of expanding benefit coverage have been implemented primarily focusing on several severe diseases, by measuring catastrophic healthcare expenditure (CHE) and the characteristics of households vulnerable to CHE. Using the Korea Health Panel 2011-2018, this study analyzed CHE trends by the targeted severe diseases and other health problems and household income and examined the determinants of CHE using binary logistic regression. Our findings showed that CHE decreased in households with the targeted severe diseases but increased in households experiencing hospitalization that were not related to the targeted diseases, which appeared to have a significantly higher likelihood of CHE in 2018 than households with the targeted severe diseases. In addition, CHE was more prevalent and increased or remained stagnant among households whose heads had health problems than others. Inequalities in CHE also increased, showing increased Concentration Index (CI) and increased incidences of CHE in the lower income quartile during the study period. These results suggest that the current policies are insufficient to achieve its financial protection goals against healthcare expenditure in South Korea. In particular, benefit expansions targeting a specific disease may cause inequitable distribution of resources and may not enhance protection against households' financial burden.

How Neighborhood Structural and Individual Characteristics Affect Frailty Progression: Evidence from the China Health and Retirement Longitudinal Study

OBJECTIVES

(1) To characterize the average trajectories of frailty over time in Chinese community-dwelling older adults; (2) To assess the effects of neighborhood structural and individual characteristics on frailty progression.

DESIGN

A nationally representative prospective cohort study.

SETTING

Communities in 28 provinces, China.

PARTICIPANTS

6238 respondents aged 60 and above in 447 communities from four waves of the China Health and Retirement Longitudinal Study.

MEASUREMENTS

Frailty was measured using the 61-item Frailty Index (FI).

RESULTS

The trajectory of FI was nonlinear, with an average growth rate of 0.025 that significantly slows down at the rate of 0.002 per year. Older, male, and uninsured respondents showed faster rates of growth in FI over time than younger, female, and insured counterparts. Respondents living in neighborhoods with a higher percentage of the older population and rural villages showed slower rates of growth in FI over time.

CONCLUSION

Expanding health insurance coverage and keeping a high clustering of the elderly in neighborhoods may be the potential strategies for population-level frailty prevention and interventions.

Comparison of adhesive single-lead ECG device and Holter test for atrial fibrillation monitoring

Background

There is insufficient validation of diagnostic benefits of extended monitoring with an adhesive single-lead ECG device compared to Holter test for routine medical care of AF patients.

Purpose

The study aimed to compare AF detection rates between 72-hour monitoring using an adhesive single-lead ECG device (mobiCARE MC-100, Seers Technology, Republic of Korea) and 24-hour Holter test among AF patients at outpatient clinics.

Methods

A total of 200 AF patients indicated for Holter test at cardiology outpatient clinics enrolled in the study. Study participants equipped both Holter and MC-100 for the first 24 hours (Figure 1). After then, only MC-100 continued ECG monitoring for additional 48 hours. AF detection during the first 24 hours was compared between two devices. The diagnostic benefits of extended monitoring with MC-100 were evaluated.

Results

During the first 24 hours, both monitoring methods detected AF in the same 40/200 (20.0%) patients (20 patients with paroxysmal and persistent AF each). Compared to 24-hour Holter, MC-100 increased AF detection rate by 1.5-fold (58/200; 29.0%) and 1.6-fold (64/200; 32.0%) with 48- and 72-hour monitoring, respectively (Figure 2A). With MC-100, the number of newly discovered patients with paroxysmal AF was 20/44 (45.5%), 18/44 (40.9%), and 6/44 (13.6%) for 24-, 48-, and 72-hour monitoring. Compared to 24-hour Holter, 72-hour monitoring with MC-100 increased the detection rate of paroxysmal AF by 2.2-fold (44/20). If only the episodes lasting over 30 seconds were counted as AF with MC-100, the detection rate of paroxysmal AF was decreased by 9.1% (Figure 2B).

Conclusion

Compared to Holter, AF detection rates could be improved with an adhesive single-lead device, especially for patients with paroxysmal AF. This device is expected to be useful for AF detection among patients whose conventional ECG tests were ineffective in documenting AF episodes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Korea Medical Device Development Fund grant funded by the Korean government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, Republic of Korea, the Ministry of Food and Drug Safety)

The left atrial low-voltage area and persistent atrial fibrillation treated with pulmonary vein isolation alone

Background

There are limited data regarding the association between the burden of the left atrial low-voltage area (LVA) and the outcome of pulmonary vein isolation (PVI) alone in persistent atrial fibrillation (PeAF).

Purpose

The study aimed to investigate the impact of the burden of LVA on the patients with PeAF treated with PVI alone.

Methods

Using a retrospective cohort of PeAF patients who underwent PVI alone, both clinical and the left atrial voltage mapping data were reviewed. LVA was defined as an area of ≤0.5 mV (bipolar) when mapped during sinus rhythm and ≤0.2 mV during AF. The high burden of LVA was defined as a case when the LVA constitutes ≥10% of the total left atrial body area. The patients were categorized into either the high or low burden groups. The recurrence of any atrial tachyarrhythmia was followed up, and multivariable Cox's regression analysis was performed.

Results

A total of 50 and 25 patients were investigated for the low burden (LVA<10%) and high burden (LVA≥10%) groups, respectively. Compared to the low burden group, the high burden group had a significantly less male proportion (56.0% versus 78.0%), a higher CHA2DS2-VASc score (median 3 versus 2), more chronic kidney disease (16.0% versus 2.0%), and a higher burden of LVA (20±11% versus 5±3%). During the median follow-up of 9.5 (6.2–16.2)months, there were 30.0% and 48.0% ofrecurrences for the low and high burden groups, respectively. Compared to the low burden group, the high burden group was associated with higher risks of both early and late recurrences (HR [95% CI] =2.67 [1.15–6.18] and 2.08 [1.03–4.20], respectively) (Figure 1). The best cut-off of LVA to predict 2-year recurrence was 10.1% (Figure 2).

Conclusion

The high burden of LVA was significantly associated with an increased risk of recurrence among PeAF patients treated with PVI alone. Tailored ablation in addition to PVI would be needed to improve outcomes in patients with PeAF having a high burden of LVA.

Funding Acknowledgement

Type of funding sources: None.

Protective effect of proton pump inhibitor against gastrointestinal bleeding in patients receiving oral anticoagulants: a systematic review and meta-analysis

Background

The concurrent use of proton pump inhibitor (PPI) in oral anticoagulant (OAC) treated patients may be associated with a lower risk of gastrointestinal bleeding (GIB), but evidence is still conflicting according to individual OACs.

Purpose

We conducted a meta-analysis to estimate the risk of GIB in patients with OAC and PPI co-therapy.

Methods

A systematic search of PubMed, EMBASE, and Cochrane was performed for studies reporting GIB risk in OAC and PPI co-therapy. Primary outcomes were total GIB and major GIB events. We calculated pooled estimates of GIB risk by a random-effect meta-analysis and reported as odds ratios (OR) and 95% CI. Stratified analyses according to the origin of GIB, ethnic groups, individual OACs, and the presence of underlying GIB risk factors were performed.

Results

A total of 10 studies (1 randomized controlled study and 9 observational studies) and 1,970,931 patients who received OAC were included. OAC and PPI co-therapy were associated with a lower risk of total GIB, and major GIB; OR (95% CI) was 0.67 (0.62–0.74) for total GIB and 0.68 (0.63–0.75) for major GIB, respectively. Among total GIB, only the risk of upper GIB was lower with OAC and PPI co-therapy (OR 0.67, 95% CI 0.64–0.70). No difference in the lower risk of primary GIB outcomes of PPI co-therapy was observed between Asians and non-Asians (p-for-difference, total GIB=0.695, major GIB=0.748, respectively) and among individual OACs except for edoxaban. The protective effect of PPI on total GIB was more significant in high-risk patients, defined as those with concurrent medication of antiplatelets or non-steroidal anti-inflammatory drugs (OR 0.62, 95% CI 0.52–0.73) and presence of high bleeding risk factors such as previous GIB history, HAS-BLED score ≥3, or underlying gastrointestinal diseases. (OR 0.65, 95% CI 0.61–0.70).

Conclusion

In patients who receive OAC, the use of PPI co-therapy was associated with a lower risk of total GIB and major GIB irrespective of ethnic group and OAC type except for edoxaban. PPI co-therapy can be considered particularly in patients on concomitant NSAID and antiplatelet use or patients with high GIB risk factors.

Funding Acknowledgement

Type of funding sources: None.

Impact of mental disease on the risk of atrial fibrillation in patients with diabetes mellitus: a nationwide population-based study

Background

Diabetes mellitus (DM) is known to increase the risk of mental disorders, which increases the health care burden in these patients. Also, DM is one of the risk factors leading to atrial fibrillation (AF), and the presence of concomitant AF and DM adds to the increased risks of stroke and death. It is uncertain whether mental disease is an independent risk factor of incident AF in patients with DM.

Purpose

To investigate whether diabetic patients with mental disease have an increased risk of AF.

Methods

Using the Korea National Health Insurance Service database, we enrolled 2,512,690 patients diagnosed with DM without AF between 2009 and 2021. Newly diagnosed AF was identified during the follow-up period. We compared the risk of AF between patients with mental disease and those without.

Results

Among the total population, 828,929 (32.99%; mean age 61.58±11.28; 56.71% female) patients were diagnosed with mental diseases (Figure 1). Anxiety (564,786 patients, 68.13%) was the most common mental disease, while depression was the second most common (313,773 patients, 37.85%). Diabetic patients with mental diseases had a higher percentage of women, hypertension, dyslipidemia, chronic kidney failure, congestive heart failure, obstructive sleep apnea, and thyroid disease. During a median 7.0 years (IQR 5.93–8.07) follow-up, 34,523 were diagnosed new-onset AF (4.66 per 1,000 person-year). In multivariate analysis, diabetic patients with mental disorders showed a higher risk of new-onset AF (HR 1.19; 95% CI 1.17–1.21; p-value <0.0001) (Figure 2). Among mental diseases, depression, insomnia, and anxiety were associated with increased risks of new-onset AF (HR 1.15; 95% CI 1.12–1.17; HR 1.15; 95% CI 1.13–1.18; and HR 1.19; 95% CI, 1.67–1.21; all p-value <0.0001, respectively), whereas bipolar disorder and schizophrenia showed non-statistically significant trends (due to small numbers). Subgroup analyses showed that younger age had significant interactions with depression, insomnia, and anxiety.

Conclusion

Mental diseases, especially depression, insomnia, and anxiety, showed an increased risk of AF in patients with DM. Awareness and prompt diagnosis and management of AF would be necessary for these high-risk populations at risk of incident AF.

Funding Acknowledgement

Type of funding sources: None.

Increased risk of atrial fibrillation in patients with uterine fibroids: a nationwide population-based study

Background

Uterine fibroid, the most common benign neoplasm of the uterus, is associated with an elevated risk of cardiovascular disease. The link between incident atrial fibrillation (AF) and the uterine fibroid is unclear because earlier studies focused primarily on the development of atherosclerosis and hypertension. We aimed to investigate the risk of AF in patients with uterine fibroid.

Methods

This is a retrospective cohort study using the Korean National Health Insurance Service database (NHIS). From 2009 to 2012, a total of 2,574,349 women (20 to 40 years old) who underwent general health examinations were included. Diagnosis of uterine fibroids and surgical treatment status was defined by the international classification of diseases, 10th revision codes, and procedural codes from the Korean NHIS. The primary outcome was newly diagnosed AF. The risk of AF according to the uterine fibroids and their surgical treatment status was evaluated using Cox proportional-hazard models.

Results

Of the total population, the mean age was 29.76±4.27 years, and 20,682 (0.8%) were identified to have uterine fibroid. Incident AF was identified in 3,868 patients (61 in the fibroid group, 3,807 in the control group) during a mean follow-up of 7.3±1.1 years. Patients of the uterine fibroid group showed a higher incidence of AF compared to the control group (0.41 and 0.20 per 1000 person-years, respectively, Figure 1). Multivariate Cox-regression analysis presented that uterine fibroid was an independent risk factor of AF: hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.16–1.93, p=0.002. Compared to the control group, uterine fibroid patients who underwent surgical treatment tend to show a lower risk for AF (HR 1.22, 95% CI 0.79–1.90) than patients without surgical treatment (HR 1.69, 95% CI 1.24–2.30), though statistical significance was indeterminate (Figure 2). After propensity score matching, patients of the uterine fibroid group showed higher risk of AF when compared to the control group (HR 1.77, 95% CI 1.32–2.63, p<0.001), which was in line with our main results. The presence of uterine fibroid was consistently associated with higher risk of AF among all subgroups except for the stroke subgroup.

Conclusion

Patients with uterine fibroids are predisposed to an increased risk of AF compared to the control group. Careful monitoring of arrhythmia development would be warranted in patients of uterine fibroid and surgical treatment as it is associated with a modest risk decrement of incident AF.

Funding Acknowledgement

Type of funding sources: None.

Increased epicardial adipose tissue volume after anthracycline chemotherapy is associated with a low risk of cardiotoxicity in breast cancer

Introduction

Chemotherapy-induced cardiotoxicity is a critical issue for patients with breast cancer. Epicardial adipose tissue (EAT) is located between the myocardial surface and the visceral layer of the pericardium. Change of EAT is associated with cardiac dysfunction.

Purpose

Considering that early detection of patients at risk of developing cardiotoxicity during and after anthracycline-based chemotherapy is the most important factor in reducing and reversing cardiac function, there is a need to identify a simple and novel imaging marker that can predict cardiotoxicity at an early stage. Therefore, the objective of the present study was to investigate the relationship between EAT and chemotherapy-induced cardiotoxicity.

Methods

This retrospective study analyzed EAT on chest computed tomography (CT) of patients with early breast cancer using automatic, quantitative measurement software between November 2015 and January 2020. Changes in EAT before and after initiation of chemotherapy were compared according to the type of anticancer drug. Subclinical cardiotoxicity was defined as worsening ≥10% in left ventricular ejection fraction to an absolute value >50% with a lower limit of normal measured with standard echocardiography.

Results

Among 234 patients with breast cancer, 85 were treated with adjuvant anthracycline-based (AC) and 149 were treated with non-anthracycline based (non-AC) chemotherapy. There was a significant increase in EAT volume index (mL/kg/m2) at the end of chemotherapy compared to that at the baseline in the AC group (3.33±1.53 vs. 2.90±1.52, p<0.001), but not in the non-AC group. During the follow-up period, subclinical cardiotoxicity developed in 20 (8.6%) patients in the total population (15.3% in the AC group and 4.8% in the non-AC group). In the multivariable analysis, EAT volume index increment after chemotherapy was associated with a lower risk of subclinical cardiotoxicity in the AC group (Odds ratio: 0.364, 95% CI: 0.136–0.971, p=0.044).

Conclusions

Measurement of EAT during anthracycline-based chemotherapy might help identify subgroups who are vulnerable to chemotherapy-induced cardiotoxicity. Early detection of EAT volume change could enable tailored chemotherapy with cardiotoxicity prevention strategies.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Technology Development Program of the National Research Foundation of Korea (NRF) funded by the Korean government (MSIT).

Paradoxical association between lipid levels and incident atrial fibrillation according to statin usage

Background

In epidemiology studies, a higher level of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) is associated with a lower risk of atrial fibrillation (AF). Statin use might exert possible confounding effects in the paradoxical relationship; however, the inverse link between AF and cholesterol level that distinguishes statin users from non-users has not been evaluated.

Objective

We investigated the epidemiological relationships of TC–AF and LDL-C–AF in statin users and non-users, respectively.

Methods

From the Korean National Health Insurance Service database, we included 9,778,014 adults who underwent a health examination in 2009 and had no prior AF history. The levels of TC and LCL-C at the health exam were categorized in quartile (Q) and decile (D) values of the total study population. The study population was grouped into statin users and non-users, and TC–AF and LDL-C–AF relationships were evaluated.

Results

867,336 (8.9%) were on statin use among the total population. Statin users showed higher TC level (208.4±55.6 vs. 194.1±39.5 mg/dL, p<0.001) and LDL-C level (123.0±102.2 vs. 121.3±226.3, p<0.001) compared to non-users. Inverse associations of TC–AF and LCL-C–AF were observed; higher levels of TC and LDL-C were associated with a lower risk of AF. The hazard ratios (HR) and 95% confidence intervals (CI) were 0.797 (0.786–0.809) for the highest quartile of TC (Q4, TC ≥218) and 0.832 (0.82–0.843) for the highest quartile of LDL-C (Q4, LDL-C ≥135) when adjusted by age, sex, lifestyle behaviors, comorbidities, and low-income status. Statin users exhibited higher AF incidence rate than non-statin users, but the association in statin users generally tracked that seen among non-statin users demonstrating similar HR in Q4 of TC [0.812 (0.790–0.835) for statin users and 0.812 (0.798–0.826) for non-statin users] and LDL-C [0.842 (0.819–0.865) for statin users and 0.849 (0.835–0.863) for non-statin users].

Conclusion

The paradoxical relationship between lipid levels (TC and LDL-C) and incident AF remained consistent both in statin users and non-users. Further research is required to investigate an underlying mechanism for the cholesterol paradox of AF which still seems evident despite the pleiotropic effects of statin.

Funding Acknowledgement

Type of funding sources: None.

Impact of metabolic syndrome on the risk of ischemic stroke in non-anticoagulated atrial fibrillation patients having low CHA2DS2-VASc scores

Background

Metabolic syndrome (MetS) predisposes to a thromboembolic state. However, conflicting results have been reported on whether MetS confers an increased risk of ischemic stroke in atrial fibrillation (AF), especially in patients with low CHA2DS2-VASc score who are not indicated for oral anticoagulant therapy.

Purpose

We investigated the risk of ischemic stroke according to the presence of MetS, the number of MetS components (metabolic burden), and the individual metabolic components in non-anticoagulated AF patients with low CHA2DS2-VASc score.

Methods

A total of 76,015 oral anticoagulant-naïve AF patients with low CHA2DS2-VASc score (0,1 in male and 1 in female) were included from the Korean National Health Insurance Service database. The status of MetS and individual metabolic components were evaluated based on health examination data within two years of AF diagnosis. We estimated the risk of ischemic stroke according to MetS, metabolic burden, and an individual component of MetS using Cox proportional-hazards models.

Results

The mean age was 49.8±11.1 years and 52,388 (68.9%) were male. The average CHA2DS2-VASc score was 0.7±0.5 and MetS was prevalent among 21,570 (28.4%) of the study population. During a mean follow-up of 5.1 years, ischemic stroke was developed in 1,395 (1.84%) patients. MetS was associated with a higher risk of ischemic stroke after adjustment for age, sex, lifestyle behaviors, low income, and cardiovascular comorbidities: adjusted hazard ratio (aHR) 1.19, 95% confidence interval (CI) 1.06–1.33, p=0.002. A positive linear correlation was observed between metabolic burden and ischemic stroke risk. Patients with five MetS components showed the highest aHR of 1.55 (95% CI 1.14–2.11, Figure 1 and Figure 2), whereas those with a single MetS component had a marginal risk of ischemic stroke (aHR 1.18, 95% CI 0.99–1.41). Among individual metabolic components, elevated blood pressure and increased waist circumference was significantly associated with an increased risk of ischemic stroke: aHR (95% CI), 1.45 (1.30–1.62), p<0.001, and 1.15 (1.03–1.30), p=0.016, respectively.

Conclusions

Among AF patients initially with CHA2DS2-VASc score 0 and 1 with no anticoagulation, the presence of MetS is associated with an increased risk of ischemic stroke. Given the linear incremental correlation between metabolic burden and ischemic stroke, special attention to the care of metabolic derangements is required in AF patients who are not indicated for anticoagulation.

Funding Acknowledgement

Type of funding sources: None.

Atrial fibrillation detection in ambulatory patients using a smart ring powered by deep learning analysis of continuous photoplethysmography monitoring

Background

Atrial fibrillation (AF) detection could be effective with photoplethysmography (PPG) signal monitoring by a wearable device.

Purpose

We aimed to validate the performance of AF detection among ambulatory patients who underwent electrical cardioversion for AF using a smart ring capable of continuous PPG monitoring and deep learning analysis.

Methods

In this prospective single-arm study, participants who underwent successful electrical cardioversion for AF were enrolled. The participants equipped a smart ring (CardioTracker, Sky Labs Inc., Seongnam, Republic of Korea) after the electrical cardioversion. The smart ring then continuously monitored PPG over 14 days to detect AF recurrence. The smart ring alarmed AF episodes based on deep learning analysis of PPG. The participants were asked to measure at least three daily ECGs using the smart ring to validate AF recurrence detected by PPG. All ECG snapshots were recorded along with lead I and saved with simultaneous PPG. ECG data were examined by the three cardiologists independently (SK, SRL, and EKC). The monitoring time, analyzable proportions of monitored signals, detection rates of AF episodes, and the diagnostic performance of PPG-based deep learning were evaluated. At the end of the monitoring, a survey on the use of the smart ring was performed.

Results

A total of 35 participants (mean age 58.9 years, male 74.3%) were enrolled. Figure 1 illustrates an example of PPG monitoring and PPG-ECG snapshots by the smart ring. The study participation period was a median of 14 days and the wearing time of the smart ring was a median of 9.2 days (IQR 7.1–11.5 days). Signal artifacts during daily activity decreased the analyzable proportions of monitored PPG by 68.5%. Irregular pulse episodes were detected by the smart ring in 29 (82.9%) participants after a median of 1 day from the cardioversion (Figure 2). A total of 2532 PPG-ECG snapshots were acquired and 1623 (64.1%) were interpretable by both the cardiologists (using ECG) and the deep learning analysis (using PPG). Comparing PPG by simultaneous ECG, the performance of AF detection by the smart ring was 98.7% for sensitivity, 97.8% for specificity, 2.2% for false positives, and 1.3% for false negatives (Figure 2). After using the smart ring, 76.9% of the participants responded that they had no discomfort in using the smart ring in daily activity and another 76.9% responded that it was helpful to monitor their disease.

Conclusion

Despite the signal artifacts during daily activity, AF detection with PPG monitoring by a smart ring could be effective for AF screening among ambulatory patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This work was supported by Sky Labs Inc, Seongnam, Republic of Korea, and by the grant No. 0320202040 from the Seoul National University Hospital Research Fund.

Sustainable Health Financing for COVID‐19 Preparedness and Response in Asia and the Pacific

To make health systems more resilient to shocks and crises, it is critical for governments to invest in core health system functions such as financing, service delivery, and governance. Ensuring sufficient resources for health is necessary for basic infrastructure including vaccines; the overall level of health expenditure and the public sources of funding are important. Funding for public health services, including infection prevention and control, surveillance, and information systems, is fundamental to ensure health systems are prepared for and respond to health emergencies. Funding should be made available for a quick and effective response to emergencies, requiring a supportive flexible public financial management system. Moreover, it is essential to mitigate the potential risks of health system collapses through innovative ways, for example, telemedicine, and mobilizing private sector providers. Vulnerable groups who are even more impacted during crises need special attention. Multisectoral cooperation is paramount to health system resilience during pandemic response.

How and why do countries make Universal Health Care policies? Interplay of country and global factors

Background

An examination of country policy making tends to reveal more complex processes that reflect domestic as well as external pressures and influences. The paper examines the interplay of external and internal, as well as other, factors in universal health care (UHC) decision-making for a select number of countries spanning the income range from low to high income.

Methods

After developing a conceptual framework to help identify variables to explore in answering our study questions, we reviewed literature on health policies and policy making, especially around the time of the adoption of relevant policies for a number of UHC reform countries, followed by a narrative review of countries for more in-depth study. For more quantitative data, we consulted databases maintained by international institutions.

Results

We found that, for low-income countries (LICs)/lower-middle-income countries (LMICs), the external environment helps set the policy agenda that drives national priorities and resource allocation decisions, while national actors take the actual decisions consistent with the interests of their constituencies and their goals. The upper-middle-income countries (UMICs) and high-income countries (HICs) in the study were less influenced by externally driven agendas and more by their own internal dynamics. For LICs/LMICs, a country’s income level as well as growth record did not appear to play any overt role at the start of the reform, whereas the UMIC/HIC countries were generally at a higher economic stage with steady growth when they initiated the reforms. The use of technical analysis and evidence to guide the UHC reform decisions was much more pronounced in the UMICs/HIC. The findings on alignment of the UHC program to national health priorities were more mixed. On sustainability, the UMICs/HIC were much more likely than LICs/LMICs to phase in their reforms, whether in terms of the geographical extension of coverage, the population groups to be covered or the expansion of the benefit package in the course of time.

Conclusions

The near-systematic use of scientific evidence by the UMICs/HIC to inform decisions on the path to UHC in contrast to the LICs/LMICs leads to the conclusion that some LICs/LMICs may have made less than optimal resource allocation decisions based on scanty evidence and factors not conducive to sustainability of their UHC efforts.

Universal health care in middle-income countries: Lessons from four countries

BACKGROUND

In this paper, we review lessons learned about Universal Health Coverage (UHC) in middle-income countries, with specific reference to achievements and challenges observed during recent years in four middle-income to upper-middle-income countries - Mexico, Turkey, The Republic of Korea and Ukraine. Three of these countries - Mexico, the Republic of Korea, Turkey are members of the Organization for Economic Cooperation and Development (OECD). Ukraine has aspired to join Western institutions like the OECD since its independence in 1991.

METHODS

The research included a combination of cross-sectional and longitudinal reviews of both statistical and contextual data, available from both published sources and available "grey literature" reports.

RESULTS

Based on the research, we conclude the following. First, reaching UHC is achievable in middle-income and upper-middle-income countries. It is not an unattainable goal reserved for upper income countries. Second, successes and failures are evident both in the case of countries that pursue a contributory health insurance path to UHC and those that pursue a core government funding path. Third, the devil is often in the detail. De jure constitutional guarantees and national health legislation are often a necessary but do not constitute a guaranteed path to success without accompanying institutional measure to secure sustainability (political and economic) and supply and demand constraints in service provision and consumer/patient behavior. De facto, in most countries expansion in health insurance coverage does not happen "with the stroke of a pen" but require years of commitment and efforts to change the supply and demand after critical legislation has been enacted. Fourth, two major approaches dominate: incremental and "big bang" health system reforms.

CONCLUSIONS

We caution against the pitfalls of over-attribution from drawing too strong conclusion from individual longitudinal country experiences ("over-determinism") and over-generalization from broad sweeping cross-sectional statistical analysis ("reductionism"). Every country is different and needs to find its own path towards UHC considering their contextual specificities, learning from the achievements and failures of others, but not try to copy their experiences.

Dual antithrombotic therapy on early clinical outcomes in patients with atrial fibrillation after percutaneous coronary intervention: a nationwide study in the era of NOAC

Background/Introduction

Recent evidence has confirmed low bleeding risk with double antithrombotic therapy, combining oral anticoagulant (OAC) and single platelet inhibitor, in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). Among the Asian AF population, most of the patients received dual antiplatelet therapy (DAPT) without OACs, even after the introduction of non-vitamin K oral anticoagulants (NOACs).

Purpose

The current nationwide study assessed 3-month ischemic and bleeding risks of DAPT in comparison to triple antithrombotic therapy among the Korean AF population undergoing PCI.

Methods

We analyzed the claims records of 11,039 patients (mean age 70 years, 66.3% male, and mean CHA2DS2-VASc score 3.2) between 2013 to 2018. Patients were categorized into triple therapy group with vitamin K antagonists (VKAs-TT), or NOACs (NOACs-TT), and DAPT group according to the antithrombotic therapy after PCI. 3-month risks of ischemic stroke, non-fatal myocardial infarction, any in-hospital death, and major bleeding were compared between groups after baseline adjustment using inverse probability weighting.

Results

A total of 1,786, 1,997, and 7,256 patients were allocated to the VKAs-TT, NOACs-TT, and DAPT groups. The DAPT group had a higher prevalence of prior MI and coronary revascularization, but had lower thromboembolic and bleeding risks than the triple antithrombotic therapy groups (mean CHA2DS2-VASc score 3.8, 4.1, and 3.5; and mean HAS-BLED score 3.3, 3.4, and 3.1 for VKAs-TT, NOACs-TT, and DAPT groups, respectively). The NOACs-TT group was associated with a lower risk of ischemic stroke (hazard ratio [HR] 0.38, 95% confidence interval [CI] 0.20–0.70) and any in-hospital death (HR 0.70, 95% CI 0.49–0.98) compared with the VKAs-TT group. The DAPT group showed a lower risk of ischemic stroke (HR 0.41, 95% CI 0.27–0.63) and major bleeding (HR 0.55, 95% CI 0.37–0.84) than the VKAs-TT group, especially in patients without prior OAC treatment. The DAPT group showed a comparable ischemic risk against the NOACs-TT group, although the risk of major bleeding was lower in the DAPT group, especially among old age (HR 0.47, 95% CI 0.29–0.78) or OACs-naive patients (HR 0.50, 95% CI 0.29–0.86).

Conclusion

Among the Asian AF population, using short-term DAPT for 3-month after PCI was associated with a lower risk of bleeding without increasing ischemic risk compared to triple antithrombotic therapy with OAC. This may be a therapeutic option in very high bleeding risk patients who have had complex PCI necessitating focus on DAPT in the initial 3 month period.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was supported by grant no 3020200200 from the Seoul National University Hospital Research Fund, by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, Republic of Korea, the Ministry of Food and Drug Safety) (Project Number: 202013B14), and by the Korea National Research Foundation funded by the Ministry of Education, Science and Technology (grant 2020R1F1A106740). Figure 1Figure 2

Antithrombotic therapy for patients with atrial fibrillation and stable coronary artery disease of 1-year and 3-year after percutaneous coronary intervention: a nationwide population-based study

Background

In a recent trial, rivaroxaban monotherapy was noninferior for efficacy and superior for safety to rivaroxaban plus single antiplatelet therapy, as antithrombotic therapy for patients with atrial fibrillation (AF) and stable coronary artery disease (CAD). However, there are limited data regarding the comparative effectiveness and safety of oral anticoagulant (OAC) monotherapy versus OAC plus single antiplatelet therapy (SAPT) in real-world practice, especially after the introduction of direct oral anticoagulants (DOAC).

Purpose

To compare the effectiveness, safety, and net clinical benefit of OAC monotherapy to OAC plus SAPT in patients with AF and stable CAD of 1-year and 3-year after percutaneous coronary intervention (PCI) in a contemporary real-world observational cohort.

Methods

Using the Korean nationwide claims database, we included AF patients who underwent PCI from January 1, 2009 to February 28, 2019. Considering dynamic changes of antithrombotic therapy according to the period after receiving PCI, the index antithrombotic treatment was independently defined at the different time after receiving PCI and we conducted two cohort: 1-year and 3-year after PCI. In each cohort, the baseline characteristics of OAC monotherapy and OAC plus SAPT groups were balanced using inverse probability of treatment weighting (IPTW) methods. To assess clinical outcomes, ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes of each outcome were analyzed.

Results

In cohort with 1-year after PCI, 678 patients with OAC monotherapy and 3159 patients with OAC plus SAPT were included. In cohort with 3-year after PCI, 1038 patients with OAC monotherapy and 2128 patients with OAC plus SAPT were enrolled. The baseline characteristics were well-balanced after IPTW between the two groups in both cohorts. Among total population, about 45% of patients prescribed DOAC as OAC treatment. Among patients with 1-year after PCI, OAC monotherapy and OAC plus SAPT showed comparable results for ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes (Figure). In cohort with 3-year after PCI, OAC monotherapy and OAC plus SAPT showed comparable results for ischemic stroke and myocardial infarction, but OAC monotherapy was associated with a lower risk of the composite clinical outcome (hazard ratio [HR] 0.762, 95% confidence interval [CI] 0.607–0.950), mainly driven by reduction of major bleeding risk (HR 0.762, 95% CI 0.607–0.950) compared to OAC plus SAPT (Figure).

Conclusion

OAC monotherapy might be, at least, comparable choice for patients with AF and stable CAD compared to OAC plus SAPT. In patients with stable CAD more than 3-years after index PCI, OAC monotherapy could be better therapeutic choice to achieve less major bleeding and positive net clinical benefit.

Funding Acknowledgement

Type of funding sources: None.

Systematic assessment of South Korea's capabilities to control COVID-19

South Korea’s COVID-19 control strategy has been widely emulated. Korea’s ability to rapidly achieve disease control in early 2020 without a “Great Lockdown” despite its proximity to China and high population density make its achievement particularly intriguing. This paper helps explain Korea’s pre-existing capabilities which enabled the rapid and effective implementation of its COVID-19 control strategies. A systematic assessment across multiple domains demonstrates that South Korea’s advantages in controlling its epidemic are owed tremendously to legal and organizational reforms enacted after the MERS outbreak in 2015. Successful implementation of the Korean strategy required more than just a set of actions, measures and policies. It relied on a pre-existing legal framework, financing arrangements, governance and a workforce experienced in outbreak management.

Assessing the impact of non-pharmaceutical interventions on the transmissibility and severity of COVID-19 during the first five months in the Western Pacific Region

While most countries in the Western Pacific Region (WPR) had similar trajectories of COVID-19 from January to May, their implementations of non-pharmaceutical interventions (NPIs) differed by transmission stages. To offer a better understanding for an implementation of multidisciplinary policies in COVID-19 control, we compared the impact of NPIs by assessing the transmissibility and severity of COVID-19 in different phases of the epidemic during the first five months in WPR. In this study, we estimated the piecewise instantaneous reproduction number (R_t) and the reporting delay-adjusted case-fatality ratio (dCFR) of COVID-19 in seven WPR jurisdictions: Hong Kong Special Administrative Region, Japan, Malaysia, Shanghai, Singapore, South Korea, and Taiwan. According to the results, implementing NPIs was associated with an apparent reduction of the piecewise R_t in two epidemic waves in general. However, large cluster outbreaks raised the piecewise R_t to a high level. We also observed relaxing the NPIs could result in an increase of R_t. The estimated dCFR ranged from 0.09% to 1.59% among the jurisdictions, except in Japan where an estimate of 5.31% might be due to low testing efforts. To conclude, in conjunction with border control measures to reduce influx of imported cases which might cause local outbreaks, other NPIs including social distancing measures along with case finding by rapid tests are also necessary to prevent potential large cluster outbreaks and transmissions from undetected cases. A comparatively lower CFR may reflect the health system capacity of these jurisdictions. In order to keep track of sustained disease transmission due to resumption of economic activities, a close monitoring of disease transmissibility is recommended in the relaxation phase. The report of transmission of SARS CoV-2 to pets in Hong Kong and to mink in farm outbreaks highlight for the control of COVID-19 and emerging infectious disease, the One Health approach is critical in understanding and accounting for how human, animals and environment health are intricately connected.

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Multidisciplinary One Health policies to combat COVID-19 are required in WPR.

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NPIs were associated with an apparent reduction in transmissibility of COVID-19.

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However, some large cluster outbreaks raised the transmissibility to a high level.

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We observed an increase in transmissibility when NPIs were partially lifted.

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A lower case-fatality ratio in WPR may reflect the health system capacity.

Feasibility Study for an Automated Engineering Change Process

Engineering change is a significant cost sink in many projects. While avoiding and mitigating the risk of change is the ideal approach, mistakes and improvements are recognized inevitably as more is learned over time about the quality of the decisions made in a product's design. This paper presents a feasibility and performance analysis of automating engineering change requests to demonstrate the promise for increasing speed, efficiency, and effectiveness of product-lifecycle-wide engineering-change-request processes. To explore this idea, a comparatively simple case study is examined both to mimic the reduced set of alterable aspects of a typical change request and to highlight the need of appropriate search algorithms as brute force methods quickly prohibitively resource intensive. Although such cases may seem trivial for human agents, with the volume of expected change requests in a typical facility, the potential opportunity gain by eliminating or reducing the amount of human effort in low level change requests accumulate into significant returns for industry on time and money. Within this work, the genetic algorithm is selected to demonstrate feasibility due to its broad scope of applicability and low barriers to deployment. Future refinement of this or other sophisticated algorithms leveraging the nature of the standard representations and qualities of alterable design features could produce tools with strong implications for process efficiency and industry competitiveness in the execution of its projects.

The effect of catastrophic health expenditure on exit from poverty among the poor in South Korea

The study aims to examine the effect of catastrophic health expenditure (CHE) on exit from poverty among the poor at the poverty line of less than 40% of median income level (MIL), analysing data from the Korean Welfare Panel Study 2008-2016 through a discrete time event history analysis. Effects of CHE on poverty exit were different between exit to near-poverty and exit to non-poverty. Households facing CHE were less likely to exit from poverty to near-poverty at the CHE thresholds of 20%-30%; however, effects of CHE were not associated with exiting from poverty to non-poverty. Considering the majority of types of exit from poverty were exit to near-poverty (about 70%), this result would raise concerns that occurrences of CHE may pose a big threat to their already limited household budget of the poor. Combined loss of income due to ill health and financial burden due to health care may force the poor to be stuck at poverty. The study was the first exploratory study in South Korea to examine the effect of CHE on exit from poverty. This study is expected to contribute to better understanding of the economic consequences of out-of-pocket payments due to health care among the poor over time. Reduction in the incidence of CHE by expanding the benefits coverage of the national health insurance in Korea can be an important step to reduce poverty.

A decade of public long-term care insurance in South Korea: Policy lessons for aging countries

South Korea proactively introduced public long-term care insurance (LTCI) in 2008 when older people were only about one-tenth of the total population. At that time, Korea switched from a tax-based, local-government-operated LTC program targeting low-income older people to the current universal public LTCI run by the National Health Insurance Service, the single public insurer. The LTCI program provides a comprehensive package of home- and institution-based care mainly targeting older people who need assistance in daily living. Over the past decade, the program has continued to expand its population and service coverage: older people in high need have been covered, and an infrastructure for service provision has been established. Future agendas include financial sustainability, care coordination, and the role of local governments. Korea's experiences suggest having an LTCI separate from the NHI has the benefit of potential de-medicalization of LTC, which, in turn, creates challenges for the coordination of health care and LTC. A centralized LTCI system with a single payer has the benefit of bigger risk-pooling, but this may become a barrier to designing integrated community care systems at the local level. There is a tradeoff between population coverage, benefits/cost coverage, and fiscal sustainability.

Health Financing Reforms for Moving towards Universal Health Coverage in the Western Pacific Region

This article provides an overview of health financing reforms across countries in the Western Pacific Region as progress is made toward universal health coverage (UHC). Moving toward UHC requires a strong health system with sustainable financing, which countries strive to achieve through various approaches appropriate to their country contexts. Great efforts have been made by financing reforms through resource mobilization, risk pooling, resource allocation, and strategic purchasing. Overall governance of health financing systems has improved within the context of service delivery and budget reforms. But there are still challenges and ongoing needs to continue expanding health financing mechanisms equitably and efficiently, improving stewardship and accountability, strengthening the transition to domestic financing, and enabling evidence-informed priority setting and benefits design processes. Asian countries are rapidly developing and moving to more prepaid financing mechanisms with government subsidies to reduce relatively high out-of-pocket expenses, while facing implementation challenges in the governance and expansion of social health insurance. The Pacific island countries, on the other hand, face stagnating economic growth and rely on government financing, with some countries receiving significant external funding, making it important to have strong stewardship and public financing systems in place. The way forward calls for continuing to strengthen the evidence generation and monitoring function to assess country progress, reorienting primary health care as the foundation of the health sector to ensure that continuity of care is affordable and accountable, and leveraging the private sector to contribute to an equitable and efficient health system.

Subnanosecond phase transition dynamics in laser-shocked iron

Iron is one of the most studied chemical elements due to its sociotechnological and planetary importance; hence, understanding its structural transition dynamics is of vital interest. By combining a short pulse optical laser and an ultrashort free electron laser pulse, we have observed the subnanosecond structural dynamics of iron from high-quality x-ray diffraction data measured at 50-ps intervals up to 2500 ps. We unequivocally identify a three-wave structure during the initial compression and a two-wave structure during the decaying shock, involving all of the known structural types of iron (α-, γ-, and ε-phase). In the final stage, negative lattice pressures are generated by the propagation of rarefaction waves, leading to the formation of expanded phases and the recovery of γ-phase. Our observations demonstrate the unique capability of measuring the atomistic evolution during the entire lattice compression and release processes at unprecedented time and strain rate.

1140 Sleep Disturbances, Lifestyle, And Self-Management In Adults With Subarachnoid Hemorrhage

Introduction

Subarachnoid hemorrhage (SAH) survivors often suffer sleep disturbances. Self-management strategies focusing on lifestyle changes and health-promoting behaviors may improve sleep in SAH survivors. Few studies have examined sleep in SAH survivors, and little is known about sleep management practices used to improve their sleep. The purposes of this study were to: 1) describe the prevalence of sleep disturbances using subjective and objective sleep measures, and 2) explore interest in and engagement with self-management practices to promote sleep health in SAH survivors.

Methods

We conducted a cross-sectional study with a convenience sample of 30 SAH survivors recruited from a university hospital. We assessed sleep quality using the Pittsburgh Sleep Quality Index (PSQI), daytime sleepiness using the Epworth Sleepiness Scale (ESS), and objective sleep using wrist actigraphy. We conducted content analysis of semi-structured interviews, with two authors each coding sleep disturbances and self-management practices addressing sleep.

Results

Seventy-three percent of SAH survivors reported poor sleep quality (PSQI > 5) and 27% had daytime sleepiness (ESS > 10). Actigraphy analysis indicated that 41% of SAH survivors slept less than 7 hours or more than 9 hours. Interview content analyses suggested 3 themes and 15 sub-categories: 1) Sleep disturbances (difficulties in falling asleep, wake after sleep onset, daytime sleepiness, too much or insufficient sleep, and poor sleep quality), 2) Sleep management practices (exercise, regular sleep schedule, relaxation, keeping busy and staying active, changing beverage intake, taking supplements, taking medication, recharging energy, and barriers to sleep management), and 3) Healthcare providers (discussing sleep problems with health care providers).

Conclusion

Sleep disturbances are highly prevalent and an urgent need exists to focus on improving sleep in SAH survivors. Developing tailored interventions that incorporate self-management and lifestyle change would be a critical next step to improve sleep and promote health in this at-risk population.

Support

This research was supported by grants from the National Institutes of Health/National Institute of Nursing Research (K23 NR017404), University of Washington Institute of Translational Health Science Translational Research Scholars Program (UL1 TR000423), and University of Washington School of Nursing Research and Intramural Funding Program.

Moderating effect of cognitive reserve on the association between grey matter atrophy and memory varies with age in older adults

BACKGROUND

Educational attainment and verbal intelligence, which indirectly reflect an individual's cognitive reserve (CR), is suggested to buffer the effect of late-life brain degradation on cognitive performance outcome. We aimed to explore how the relationship between whole grey matter volume (GMV) and episodic memory function is altered by CR proxy as well as age in healthy older adults.

METHODS

Elderly Verbal Learning Test (EVLT) and structural magnetic resonance imaging were administered to 110 community-residing older adults. Moderated moderation model tested whether the association between whole GMV and episodic memory was moderated by both CR and chronological age.

RESULTS

The results showed that the moderating effect of CR on Immediate Recall, Short-delay Recall, and Recognition scores of EVLT differed across age groups. The elderly with higher CR showed steeper GMV effect on EVLT at the Age-Younger condition, while such moderating effect was reversed in the Age-Older condition, suggesting an alleviated brain atrophy effect in higher CR elderly.

CONCLUSION

These findings suggest that although higher CR elderly may exhibit earlier GMV-related memory decline, the buffering effect of CR on the cognitive decline due to brain atrophy would become more evident in old-old elderly people who are likely to have accumulated more neuropathological changes. This study underscores chronological age as an important moderating factor in examining the moderating role of CR in late-life memory function.

P4782Direct comparison of dabigatran, apixaban, rivaroxaban and edoxaban for effectiveness and safety among patients with non-valvular atrial fibrillation

Background

Although the prescription of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with non-valvular atrial fibrillation (AF) has been rapidly increasing in Asian countries since their introduction, limited evidence exists on the effectiveness and safety of warfarin and all 4 available NOACs from current clinical practice in the Asian population. We aimed to evaluate comparative effectiveness and safety of warfarin and all 4 available NOACs

Methods

We studied a retrospective observational cohort of oral anticoagulant (OAC) naïve non-valvular AF patients treated with warfarin or NOACs (rivaroxaban, dabigatran, apixaban, or edoxaban) from January 2015 to December 2017, based on the Korean Health Insurance Review and Assessment database. For the comparisons, warfarin to 4 NOACs and NOAC to NOAC comparison cohorts were balanced using inverse probability of treatment weighting (IPTW). Ischemic stroke, intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), major bleeding (MB) and a composite clinical outcome were evaluated.

Results

A total of 116,804 patients were included (25,420 with warfarin, 35,965 with rivaroxaban, 17,745 with dabigatran, 22,177 with apixaban, and 15,496 with edoxaban). Patients treated with warfarin were younger (mean age 67 years) compared to NOAC users (71 to 73 years) and had lower mean CHA2DS2-VASc score (3.18) than the NOAC groups (3.58 to 3.76). Among the NOAC users, patients prescribed apixaban were older (mean age 73 years) than other NOAC groups (71 to 72 years), had higher mean CHA2DS2-VASc score (3.76) than others (3.55 to 3.63) and higher burden of comorbidities. More than half of patients were prescribed reduced dose regimes. After IPTW, all baseline covariates were well balanced across 5 treatment groups. Compared with warfarin, all NOACs were associated with lower risks of ischemic stroke, ICH, GIB, MB and composite outcome (Figure A). Apixaban and edoxaban showed a lower rate of ischemic stroke compared with rivaroxaban and dabigatran (Figure B). Apixaban, dabigatran and edoxaban had a lower rate of GIB and MB compared with rivaroxaban. The composite clinical outcome was non-significantly different for apixaban vs edoxaban.

Conclusions

In this large contemporary observational Asian cohort, all 4 NOACs were associated with lower rates of ischemic stroke and major bleeding compared to warfarin. Differences in clinical outcomes between NOACs may give useful guidance for physicians to choose drugs to fit their particular patient clinical profile.

Divide and conquer: A perspective on biochips for single-cell and rare-molecule analysis by next-generation sequencing

Recent advances in biochip technologies that connect next-generation sequencing (NGS) to real-world problems have facilitated breakthroughs in science and medicine. Because biochip technologies are themselves used in sequencing technologies, the main strengths of biochips lie in their scalability and throughput. Through the advantages of biochips, NGS has facilitated groundbreaking scientific discoveries and technical breakthroughs in medicine. However, all current NGS platforms require nucleic acids to be prepared in a certain range of concentrations, making it difficult to analyze biological systems of interest. In particular, many of the most interesting questions in biology and medicine, including single-cell and rare-molecule analysis, require strategic preparation of biological samples in order to be answered. Answering these questions is important because each cell is different and exists in a complex biological system. Therefore, biochip platforms for single-cell or rare-molecule analyses by NGS, which allow convenient preparation of nucleic acids from biological systems, have been developed. Utilizing the advantages of miniaturizing reaction volumes of biological samples, biochip technologies have been applied to diverse fields, from single-cell analysis to liquid biopsy. From this perspective, here, we first review current state-of-the-art biochip technologies, divided into two broad categories: microfluidic- and micromanipulation-based methods. Then, we provide insights into how future biochip systems will aid some of the most important biological and medical applications that require NGS. Based on current and future biochip technologies, we envision that NGS will come ever closer to solving more real-world scientific and medical problems.

Abstract P4-08-22: Impact of application of AJCC 8th edition on survival rate of the breast cancer

Background

The AJCC 8 edition has changed much in comparison with the 7 edition. In addition to TNM stage, biologic marker (ER, PR, HER2), Histologic grade and multigene assays (oncotype Dx.) should be considered for staging. and it has been applied since January 1, 2018.

patients were recategorized and analyzed in order to know if this more complex classification helps to predict the real prognosis of the patients,

Method

We review patients who were diagnosed and treated as breast cancer at Konyang Universty Hospital. we studied retrospectively 582 patients who were followed up and were able to review.

Stage was classified according to AJCC 7th edition and AJCC 8th edition. survival rate of each stage were analyzed in both editions.

Result

Mean follow up period was 68.6 months. Total 582 patients were included. There was no change in the stage in 257 patients. In 195 patients, the stage was elevated and in 130 patients, the stage was changed down. When classified as AJCC 7th edition, the 5year-survival rate was 95.9% in stage I, 97.9% in stage II, 93.1% in stage III and 89.9% in stage IV. The survival rate of patients in stage I was lower than that of stage II. However, when the AJCC 8th edition was applied, the 5- year survival rate was 97.9% in stage I, 96.9% in stage II, 92.2% in stage III, and 89.9% in stage IV. In 8th edition, the patients in lower stage has higher survival rate.

Conclusion

The prediction of survival rate by stage was more accurate and the difference in survival rate of each stages was more clearly distinguished when The AJCC 8th edition was applied than AJCC 7th edition. AJCC 8th edition was reliable and useful for prediction of prognosis of breast cancer patient.

Citation Format: Kwon S, Yoon DS, Bae IE, Choi WJ, Choi IS, Lee SE, Moon JI, Sung NS, Park SM. Impact of application of AJCC 8th edition on survival rate of the breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-22.

Abstract P2-07-10: Not presented

This abstract was not presented at the conference.

Citation Format: Lee H-B, Kim KE, Ju YW, Jung J-G, Ryu H-S, Lee SB, Lee JW, Lee HJ, Kim M-S, Kwon S, Kim J, Kim C, Moon H-G, Noh D-Y, Ahn S-H, Park I-A, Kim S, Yoon S, Kim A, Han W. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-10.

How Does Stronger Protection of Intellectual Property Rights Affect National Pharmaceutical Expenditure? An Analysis of OECD Countries

Intellectual property rights (IPR) protection for pharmaceuticals has been comprehensive and strict since the establishment of the World Trade Organization in 1995 and the subsequent implementation of the TRIPS Agreement. This study investigated the relationship between the level of IPR and national pharmaceutical expenditure using panel data of 22 OECD countries from 1970 to 2009. The patent index was used to measure the level of national protection for IPR along with other covariates: GDP per capita, the percentage of population aged over 65, number of doctors, proportion of public financing among total pharmaceutical expenditure, under-5 mortality, price index, and period indicators. The regression analysis results showed that the level of IPR protection was significantly correlated with pharmaceutical spending even after controlling for various factors that affect pharmaceutical expenditure. The results were consistent in OLS regression and GLS regression. However, the effect of IPR was stronger and more significant in countries with a relatively small-sized pharmaceutical market than in those with big market. Many developed countries incur a financial burden due to rapidly growing pharmaceutical expenditure; therefore, the results of this study present the possibility that stronger IPR would produce welfare loss in developed countries.