Use of machine learning techniques for identifying ischemic stroke instead of the rule-based methods: a nationwide population-based study

BACKGROUND

Many studies have evaluated stroke using claims data; most of these studies have defined ischemic stroke using an operational definition following the rule-based method. Rule-based methods tend to overestimate the number of patients with ischemic stroke.

OBJECTIVES

We aimed to identify an appropriate algorithm for identifying stroke by applying machine learning (ML) techniques to analyze the claims data.

METHODS

We obtained the data from the Korean National Health Insurance Service database, which is linked to the Ilsan Hospital database (n = 30,897). The performance of prediction models (extreme gradient boosting [XGBoost] or gated recurrent unit [GRU]) was evaluated using the area under the receiver operating characteristic curve (AUROC), the area under precision-recall curve (AUPRC), and calibration curve.

RESULTS

In total, 30,897 patients were enrolled in this study, 3145 of whom (10.18%) had ischemic stroke. XGBoost, a tree-based ML technique, had the AUROC was 94.46% and AUPRC was 92.80%. GRU showed the highest accuracy (99.81%), precision (99.92%) and recall (99.69%).

CONCLUSIONS

We proposed recurrent neural network-based deep learning techniques to improve stroke phenotyping. This can be expected to produce rapid and more accurate results than the rule-based methods.

Trends and Clinical Characteristics of Next-Generation Sequencing-Based Genetic Panel Tests: An Analysis of Korean Nationwide Claims Data

PURPOSE

In the modern era of precision medicine, next-generation sequencing (NGS) is employed for a variety of clinical purposes. The aim of this study was to investigate the trends and clinical characteristics of NGS testing in South Korea.

MATERIALS AND METHODS

This nationwide, population-based, retrospective cohort study examined National Health Insurance Service claims data from 2017 to 2021 for NGS and from 2008 to 2021 for gene-targeted anticancer drugs.

RESULTS

Among the total 98,748 claims, there were 51,407 (52.1%) solid cancer panels, 30,173 (30.5%) hereditary disease panels, and 17,168 (17.4%) hematolymphoid cancer panels. The number of annual claims showed a persistent upward trend, exhibiting a 5.4-fold increase, from 5,436 in 2017 to 29,557 in 2021. In the solid cancer panel, colorectal cancer was the most common (19.2%), followed by lung cancer (18.8%). The annual claims for targeted cancer drugs have increased 25.7-fold, from 3,932 in 2008 to 101,211 in 2020. Drugs for the treatment of lung cancer accounted for 488,819 (71.9%) claims. The number of patients who received non-hereditary NGS testing has substantially increased, and among them, the count of patients prescribed targeted anticancer drugs consistently rose from 508 (13.9%) in 2017 to 2,245 (12.3%) in 2020.

CONCLUSION

This study highlights the rising nationwide demand for comprehensive genetic testing for disease diagnosis and treatment following NGS reimbursement by the National Health Insurance in South Korea, in addition to the need for greater utilization of targeted anticancer drugs.

Association of systolic blood pressure with incident chronic kidney disease estimated by marginal structural model: a nationwide population-based study

Background

We aimed to investigate the association between systolic blood pressure (SBP) and risk of incident chronic kidney disease (CKD) using marginal structural model (MSM) to reflect mutual effects of exposure and confounders on the outcome.

Methods

A total of 195,970 adults with an estimated glomerular filtration rate (eGFR) of >60 mL/min/1.73 m2 and no proteinuria were included from a nationally representative sample cohort of Korean population. SBPs were measured through national health examinations. Primary outcome was incident CKD, defined as a composite of events of a decrease in eGFR to <60 mL/min/1.73 m2 or a newly developed proteinuria for at least two consecutive measurements. The association between SBP and risk of CKD was examined using Cox model, time-dependent Cox model, and MSM.

Results

During a follow-up of 5 years, CKD occurred in 3,355 participants (1.7%). With SBP treated as a continuous variable, each 10-mmHg increment was associated with higher risk for incident CKD, regardless of analytical models used. Compared to SBP group of 120-129 mmHg, hazard ratios (95% confidence intervals) for incident CKD for SBP groups of <110, 110-119, 130-139, and ≥140 mmHg in MSM were 0.70 (0.62-0.80), 0.85 (0.77-0.95), 1.16 (1.05-1.27), and 1.63 (1.47-1.80), respectively.

Conclusion

In this nationwide study, we found a significant relationship between higher SBP and higher risk of incident CKD. Further studies are warranted to verify the potential significance of high SBP as a preventable risk factor for the development of CKD in those with preserved renal function.

Risk for depression and anxiety in patients with facial palsy based on population-based data from Korea

BACKGROUND

Several studies point out the association of facial palsy with psychiatric distress such as depression and anxiety. However, there have been few studies on this association based on population-based data.

OBJECTIVES

To investigate the risk for depression and anxiety disorders in patients with Bell's palsy and in those with Ramsay Hunt syndrome.

MATERIALS AND METHODS

This retrospective study included data from the Korean National Health Insurance Service National Sample Cohort. From 2006 to 2015, patients with Bell's palsy and those with Ramsay Hunt syndrome were defined using diagnostic and medication claim codes. Patients with depression or anxiety were defined using diagnostic and medication claim codes. Occurrences of depression and anxiety were included in analyses.

RESULTS

There were significantly higher risks for depressive and anxiety disorders in the group of patients with Bell's palsy than in the control group, as well as in the group of patients with Ramsay Hunt syndrome than in the control group.

CONCLUSIONS AND SIGNIFICANCE

There were significantly higher risks for depression and anxiety in patients with facial palsy including Bell's palsy and Ramsay Hunt syndrome based on population-based data from Korea.

Is ulnar shortening osteotomy or the wafer procedure better for ulnar impaction syndrome?: A systematic review and meta-analysis

BACKGROUND

Wrist pain on the ulnar side is often caused by ulnar impaction syndrome (UIS). Idiopathic UIS requires surgical treatment when conservative treatment fails. The 2 main surgical procedures used are the wafer procedure and ulnar shortening osteotomy (USO) of the metaphysis or diaphysis. This review aimed to analyze comparative studies of the 2 procedures in UIS to determine clinical outcomes and complications.

METHODS

One prospective and 5 retrospective comparison trials were retrieved from the PubMed, Embase, and Cochrane Library databases. The primary outcomes were treatment effectiveness; pain visual analog scale (VAS), disabilities of the arm, shoulder, and hand (DASH) score, Mayo wrist, and Darrow scores. The incidence of postoperative complications formed the secondary outcome.

RESULTS

The selected studies included 107 patients who underwent the wafer procedure (G1) and 117 patients who underwent USO (G2). The wafer procedure had the benefits of less postoperative immobilization and an early return to work. However, there were no significant differences in the postoperative pain improvement and functional scores. All 6 studies reported high total complication rates and reoperation with USO. The most frequent complication was implant-related discomfort or irritation; subsequent plate removal was the most common reason for a secondary operation.

CONCLUSIONS

There was no difference in pain improvement or the postoperative functional score between the groups. Nevertheless, postoperative complications were the major pitfalls of USO. As the specialized shortening system advances further, a high-level study will be necessary to determine the surgical option in UIS.

Uric Acid and Risk of Cardiovascular Disease and Mortality: A Longitudinal Cohort Study

BACKGROUND

This study aimed to examine the association of serum uric acid levels with incident cardiovascular disease and mortality in Korean adults without gout.

METHODS

This large longitudinal cohort study included adults aged > 19 years who had serum uric acid levels measured at least once at the National Health Insurance Service Ilsan Hospital from January 1, 2006 to December 31, 2015. Longitudinal data on person-level cardiovascular disease and cardiovascular mortality were linked to the National Health Insurance Service claims database and National Death Index.

RESULTS

Among a total of 92,454 study participants with a median follow-up of 4.7 years, 7,670 (8.3%) composite events of cardiovascular disease or cardiovascular mortality were observed. Multivariable Cox proportional-hazards models revealed that each 1 mg/dL increment in uric acid level was associated with a 6% higher risk of composite outcomes. Compared with that for the uric acid level category of 4.0 to < 5.0 mg/dL, adjusted hazard ratios (95% confidence interval) for uric acid level categories of 5.0 to < 6.0, 6.0 to < 7.0, and ≥ 7.0 mg/dL were 1.10 (1.04-1.18), 1.20 (1.11-1.30), and 1.36 (1.25-1.47), respectively. In the secondary analyses for cardiovascular disease or cardiovascular mortality examined separately, a higher uric acid level was similarly associated with a higher risk of each adverse outcome. These associations were generally consistent across clinically relevant subgroups.

CONCLUSION

A graded association was noted between serum uric acid levels and cardiovascular risk, suggesting that higher uric acid levels may adversely affect cardiovascular health and survival in individuals without gout.

Corrigendum: Introducing a healthcare-assistive robot in primary care: a preliminary questionnaire survey

[This corrects the article DOI: 10.3389/frobt.2023.1123153.].

Introducing a healthcare-assistive robot in primary care: a preliminary questionnaire survey

A Healthcare-assistive Infection-control RObot (HIRO) is a healthcare-assistive robot that is deployed in an outpatient primary care clinic to sanitise the premises, monitor people in its proximity for their temperature and donning of masks, and usher them to service points. This study aimed to determine the acceptability, perceptions of safety, and concerns among the patients, visitors, and polyclinic healthcare workers (HCWs) regarding the HIRO. A cross-sectional questionnaire survey was conducted from March to April 2022 when the HIRO was at Tampines Polyclinic in eastern Singapore. A total of 170 multidisciplinary HCWs serve approximately 1,000 patients and visitors daily at this polyclinic. The sample size of 385 was computed using a proportion of 0.5, 5% precision, and 95% confidence interval. Research assistants administered an e-survey to gather demographic data and feedback from 300 patients/visitors and 85 HCWs on their perceptions of the HIRO using Likert scales. The participants watched a video on the HIRO's functionalities and were given the opportunity to directly interact with it. Descriptive statistics was performed and figures were presented in frequencies and percentages. The majority of the participants viewed the HIRO's functionalities favourably: sanitising (96.7%/91.2%); checking proper mask donning (97%/89.4%); temperature monitoring (97%/91.7%); ushering (91.7%/81.1%); perceived user friendliness (93%/88.3%), and improvement in the clinic experience (96%/94.2%). A minority of the participants perceived harm from the HIRO's liquid disinfectant (29.6%/31.5%) and that its voice-annotated instructions may be upsetting (14%/24.8%). Most of the participants accepted the HIRO's deployment at the polyclinic and perceived it to be safe. The HIRO used ultraviolet irradiation for sanitisation during after-clinic hours instead of disinfectants due to the perceived harm.

Association between hearing loss and trauma based on population data of Korea

BACKGROUND

Although several studies have been conducted to assess the association between hearing loss (HL) and trauma, no studies have analyzed trauma comprehensively based on population-based data.

OBJECTIVES

To investigate the association between HL and trauma in daily life using National Health Insurance Service National Sample Cohort data of Korea.

MATERIALS AND METHODS

People who were registered with severe or mild hearing disability by the Korean government from 2002 to 2015, were included in this study. Trauma was defined as an outpatient visit or admission under diagnostic codes associated with trauma. The risk for trauma was analyzed using multiple logistic regression model.

RESULTS

There were 5,114 subjects in the mild hearing disability group and 1,452 in the severe hearing disability group. The risk for trauma was significantly higher in the mild and severe hearing disability groups than in the control group. The risk was higher in the mild hearing disability group than in the severe hearing disability group.

CONCLUSIONS AND SIGNIFICANCE

Individuals with hearing disability are at a higher risk for trauma based on population-based data in Korea, which indicates that HL increases the risk for trauma.

Association between familial aggregation of chronic kidney disease and its incidence and progression

This study aimed to examine the association between familial aggregation of chronic kidney disease (CKD) and risk of CKD development and its progression. This nationwide family study comprised 881,453 cases with newly diagnosed CKD between 2004 and 2017 and 881,453 controls without CKD matched by age and sex, using data from the Korean National Health Insurance Service with linkage to the family tree database. The risks of CKD development and disease progression, defined as an incident end-stage renal disease (ESRD), were evaluated. The presence of any affected family member with CKD was associated with a significantly higher risk of CKD with adjusted ORs (95% CI) of 1.42 (1.38-1.45), 1.50 (1.46-1.55), 1.70 (1.64-1.77), and 1.30 (1.27-1.33) for individuals with affected parents, offspring, siblings, and spouses, respectively. In Cox models conducted on patients with predialysis CKD, risk of incident ESRD was significantly higher in those with affected family members with ESRD. The corresponding HRs (95% CI) were 1.10 (1.05-1.15), 1.38 (1.32-1.46), 1.57 (1.49-1.65), and 1.14 (1.08-1.19) for individuals listed above, respectively. Familial aggregation of CKD was strongly associated with a higher risk of CKD development and disease progression to ESRD.

Consumer Experience of Mistreatment and Fraud in Financial Services: Implications from an Integrative Consumer Vulnerability Framework

This study utilizes the National Financial Well-Being Survey (NFWS) from the Consumer Financial Protection Bureau (CFPB) to investigate the profiles of American consumers who experience mistreatment or a type of fraud in financial services (compromised accounts). An integrative consumer vulnerability framework was used as the theoretical framework to examine how disadvantaged consumer characteristics and vulnerable consumer characteristics are associated with mistreatment and compromised accounts. Consumers in vulnerable states, due to low financial capability, cognitive decline, material hardships, financial shocks, and more exposure to various financial services, were more likely to report experiencing mistreatment and having their financial accounts compromised. Consumers from higher socio-economic status were more likely to have been victims of mistreatment and compromised accounts in financial services. These findings offer implications for consumer financial education and protection.

Burden of comorbidities and medication use in childbearing women with rheumatic diseases: a nationwide population-based study

BACKGROUND/AIMS

We aimed to estimate the prevalence of comorbidities and medication use in Korean women with rheumatic diseases (RDs) during their childbearing years.

METHODS

We included women aged 20 to 44 years with seropositive rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and ankylosing spondylitis (AS) (n = 41,547) and age-matched women without seropositive RA, SLE, and AS (n = 208,941) from the National Health Insurance Service-National Health Information Database (2009 to 2016). The prevalence of hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus (DM), and cancer and the use of nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CSs), and disease-modifying anti-rheumatic drugs (DMARDs) were estimated.

RESULTS

Women of childbearing age with RDs were more likely to have at least one of the measured comorbidities than the controls (odds ratio [OR], 3.0; 95% confidence interval [CI], 2.9 to 3.1). The OR (95% CI) was 2.9 (2.8 to 3.0) for HTN, 2.8 (2.7 to 2.9) for HLD, 1.4 (1.4 to 1.5) for DM, and 1.3 (1.3 to 1.4) for cancer. The SLE group had the highest prevalence and odds of all four measured comorbidities. Almost all (97.9%) women of childbearing age with RDs were taking RD-related medications (NSAIDs, 81.6%; CSs, 77.8%; DMARDs, 87.3%). The RD group was 13.8 times more likely to take NSAIDs and 68.2 times more likely to take CSs than the controls. Use of NSAIDs was more prevalent in RA and AS than SLE, whereas use of CSs and DMARDs was more prevalent in RA and SLE than AS.

CONCLUSION

Korean women with RDs have a greater burden of comorbidities and medication use during their childbearing years than women without RDs of the same age.

Ventricular arrhythmias and sudden cardiac death caused by mitral valve prolapse: should we operate and when?

Background

Several autopsy and observational studies have investigated the link between mitral valve prolapse (MVP) and sudden cardiac death (SCD) due to the well accepted yet rare occurrence of complex ventricular arrhythmia (VA) in this cohort. Few studies however have investigated whether arrhythmia burden and more importantly SCD are reduced following surgical correction of MVP.

Purpose

To investigate the impact of mitral valve surgery (MVS) (replacement or repair) on VA and SCD in patients with MVP.

Methods

A systematic review of the current literature was conducted using an electronic search of the PubMed database in October 2021. Studies were included if subjects had undergone mitral valve (MV) repair or replacement with documented rates of arrythmias/SCD pre- and post-intervention. Small patient numbers in individual reports precluded formal meta-analysis and results were reported on a per study basis.

Results

19 identified studies (10 cohort studies, nine case studies) comprised 1322 patients with a pooled mean age of 63.4 years and 38.9% were female. 748 of the 1322 patients underwent MVS: 263 MV repair, 18 MV replacement (one with leaflet and papillary muscle excision), two MV repair with Maze procedure, 177 percutaneous transcatheter MV repair, 45 annuloplasty with or without valve repair, and in 243 cases the surgical method was not specified.

Of the 10 included cohort studies, seven of the eight which investigated rates of VA post MVS concluded there was a significant reduction, while one reported the predisposition to arrythmia persisted after relieving the abnormal mechanical effects of non-ischaemic MR (75% due to MVP). One study reported a reduction in SCD post MVS. Each of the nine included case studies showed a reduction in VA post MVS. One study showed mitral annular disjunction (MAD) was independently associated with a higher risk of arrhythmic events, this link persisting with time dependent MVS although reduced compared to medical management.

Conclusions

The underlying mechanisms for VA and SCD associated with MVP are not completely understood, and guidelines for the surgical correction of MVP based on arrhythmic and SCD risk are lacking. This systematic review illustrates a possible reduction in VA following MVS. Further identification of patients at risk of SCD, and potential use of risk stratification algorithms, would allow for consideration of earlier management and appropriate use of implantable cardioverter-defibrillators (ICD) placement / MVS with an expected survival benefit.

Funding Acknowledgement

Type of funding sources: None.

The Effect of Chronic Disease Management Program on the Risk of Complications in Patients With Hypertension in Korea

BACKGROUND

A chronic disease management program was implemented in April 2012 to lower out-of-pocket costs for repeat visits to the same clinic. The aim of this study was to investigate the association between participating in this program and the onset of complications among patients with hypertension using whole-nation claims data.

METHODS

We used National Health Insurance Service data (2011-2018) and patients with newly detected hypertension from 2012 to 2014 were selected. Chronic disease management program reduces the out-of-pocket expenses of consultation fee from 30% to 20% when patients enroll in this program by agreeing to visit the same clinic for the treatment of hypertension or diabetes. As the dependent variable, acute myocardial infarction (MI), stroke, chronic kidney disease (CKD), and heart failure (HF) were selected. For analysis, cox proportional hazards model was used.

RESULTS

Total participants were 827,577, among which 102,831(12.6%) subjects participated in the chronic disease management. Participants of the chronic disease management program were more likely to show lower hazard ratios (HRs) than those of non-participants in terms of all complications (MI: HR, 0.75; 95% confidence interval [CI], 0.68-0.82; stroke: HR, 0.75; 95% CI, 0.72-0.78; CKD: HR, 0.90; 95% CI, 0.85-0.96; HF: HR, 0.56; 95% CI, 0.52-0.61).

CONCLUSION

The results showed that participants of the chronic disease management program were less likely to have hypertension complications compared to non-participants. Enhancing the participation rate may be related to better outcomes and reducing medical expenses among patients with chronic diseases.

Secular Trends of Incidence, Prevalence, and Healthcare Economic Burden in ANCA-Associated Vasculitis: An Analysis of the 2002–2018 South Korea National Health Insurance Database

Objectives

The incidence and prevalence of AAV in Asia remain poorly understood, especially in a nationwide setting. This study investigated the incidence, prevalence, and healthcare burden of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in South Korea by analyzing a national database.

Methods

This study included patients with AAV identified from the National Health Insurance Service Database of South Korea from 2002 to 2018. Patients were diagnosed with AAV in a general or tertiary hospital and were registered in the individual payment beneficiaries program or were prescribed glucocorticoids. A calendar-based meteorological definitions were adopted to assess the differences in the incidence of AAV according to season. The average healthcare expenditure and patient outcomes of mortality and end-stage renal disease (ESRD) in patients with AAV were compared to 1:10 age, sex and residential area matched controls.

Results

A total of 2,113 patients [708, 638, and 767 with microscopic polyangiitis (MPA), granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis, respectively] were identified. The annual incidence and prevalence of AAV increased continuously, and MPA being the most common disease subtype after 2015. The highest incidence and prevalence of AAV was 0.48/100,000 person-years (PY) and 2.40/100,000 PY in 2017 and 2018, respectively. There were no significant differences in monthly and seasonal incidence of AAV. The average expense of medical care, overall mortality, and ESRD rates of patients with AAV were higher in patients with AAV than in controls, especially in the case of MPA.

Conclusion

An increasing trend of AAV diagnosis observed is consistent with the evidence that AAV is more common in recent years; however, a relatively lower incidence and prevalence was observed compared to that in Western countries. The higher medical cost and rates of mortality and ESRD in AAV emphasize the early recognition and implementation of optimal treatment for these patients.

Whole genome and transcriptome analysis enhances precision cancer treatment options

BACKGROUND

Recent advances are enabling delivery of precision genomic medicine to cancer clinics. While the majority of approaches profile panels of selected genes or hotspot regions, comprehensive data provided by whole genome and transcriptome sequencing and analysis (WGTA) presents an opportunity to align a much larger proportion of patients to therapies.

PATIENTS AND METHODS

Samples from 570 patients with advanced or metastatic cancer of diverse types enrolled in the Personalized OncoGenomics (POG) program underwent WGTA. DNA-based data, including mutations, copy number, and mutation signatures, were combined with RNA-based data, including gene expression and fusions, to generate comprehensive WGTA profiles. A multidisciplinary molecular tumour board used WGTA profiles to identify and prioritize clinically actionable alterations and inform therapy. Patient responses to WGTA-informed therapies were collected.

RESULTS

Clinically actionable targets were identified for 83% of patients, 37% of whom received WGTA-informed treatments. RNA expression data were particularly informative, contributing to 67% of WGTA-informed treatments; 25% of treatments were informed by RNA expression alone. Of a total 248 WGTA-informed treatments, 46% resulted in clinical benefit. RNA expression data were comparable to DNA-based mutation and copy number data in aligning to clinically beneficial treatments. Genome signatures also guided therapeutics including platinum, PARP inhibitors, and immunotherapies. Patients accessed WGTA-informed treatments through clinical trials (19%), off-label use (35%), and as standard therapies (46%) including those which would not otherwise have been the next choice of therapy, demonstrating the utility of genomic information to direct use of chemotherapies as well as targeted therapies.

CONCLUSIONS

Integrating RNA expression and genome data illuminated treatment options that resulted in 46% of treated patients experiencing positive clinical benefit, supporting the use of comprehensive WGTA profiling in clinical cancer care.

CLINICAL TRIAL NUMBER

NCT02155621.

Distribution of Medical Service Use for Facial Palsy Between Medicine and Traditional Korean Medicine Based on Population-Based Data of Korea

We investigated the distribution of medical service uses for Bell's palsy and Ramsay Hunt syndrome between medicine and traditional Korean medicine using the National Health Insurance Service National Sample Cohort data of Korea from 2006 to 2015. Patients were identified with diagnostic codes and medication or treatment claim codes. For Bell's palsy, there were 5,970 (68.8%) patients who used traditional Korean medical service only, whereas for Ramsay Hunt syndrome, there were 749 (93.6%) patients who used medical service only. The proportion of traditional Korean medical service use was higher than that of medical service use in patients with Bell's palsy, while the opposite was found in patients with Ramsay Hunt syndrome.

Risk of Pregnancy Complications and Low Birth Weight Offsprings in Korean Women With Rheumatic Diseases: A Nationwide Population-Based Study

BACKGROUND

To determine the risk of pregnancy complications and adverse offspring outcomes in Korean women with rheumatic diseases (RDs).

METHODS

Women aged 20-44 years with pregnancies ending in delivery were identified from the National Health Insurance Service-National Health Information Database (2009-2016). Women with RD including systemic lupus erythematosus (SLE), seropositive rheumatoid arthritis (SPRA), and ankylosing spondylitis (AS) (n = 4,284) were age-matched with controls (n = 26,023). Outcome variables included threatened abortion (TA), preterm birth (PB), preeclampsia/eclampsia (PE/E), intrauterine growth retardation (IGR), urinary tract infection, low birth weight (LBW) offsprings, and offspring death within 1 year of birth.

RESULTS

Women with RDs had increased risks for cesarean section delivery (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.4-1.6), TA (OR, 1.4; 95% CI, 1.2-1.5), PB (OR, 2.4; 95% CI, 1.9-3.2), PE/E (OR, 4.4; 95% CI, 3.3-5.9), and IGR (OR, 2.4; 95% CI, 2.0-3.1) than the controls. The risk of pregnancy complications was increased in SLE and SPRA pregnancies but not in AS pregnancies. Offsprings of women with RDs had an increased risk of LBW (OR, 4.0; 95% CI, 3.2-4.9). The offspring mortality rate within 1 year of birth was higher in women with RDs (6.2/10,000 persons) than in the controls (4.9/10,000 persons).

CONCLUSION

Women with RDs are at a risk of developing pregnancy complications, and the risk of LBW offsprings and offspring death within 1 year of birth is increased in these women. Therefore, this population requires special attention during their childbearing years.

Prediction of the risk of developing hepatocellular carcinoma in health screening examinees: a Korean cohort study

Background

Almost all Koreans are covered by mandatory national health insurance and are required to undergo health screening at least once every 2 years. We aimed to develop a machine learning model to predict the risk of developing hepatocellular carcinoma (HCC) based on the screening results and insurance claim data.

Methods

The National Health Insurance Service-National Health Screening database was used for this study (NHIS-2020-2-146). Our study cohort consisted of 417,346 health screening examinees between 2004 and 2007 without cancer history, which was split into training and test cohorts by the examination date, before or after 2005. Robust predictors were selected using Cox proportional hazard regression with 1000 different bootstrapped datasets. Random forest and extreme gradient boosting algorithms were used to develop a prediction model for the 9-year risk of HCC development after screening. After optimizing a prediction model via cross validation in the training cohort, the model was validated in the test cohort.

Results

Of the total examinees, 0.5% (1799/331,694) and 0.4% (390/85,652) in the training cohort and the test cohort were diagnosed with HCC, respectively. Of the selected predictors, older age, male sex, obesity, abnormal liver function tests, the family history of chronic liver disease, and underlying chronic liver disease, chronic hepatitis virus or human immunodeficiency virus infection, and diabetes mellitus were associated with increased risk, whereas higher income, elevated total cholesterol, and underlying dyslipidemia or schizophrenic/delusional disorders were associated with decreased risk of HCC development (p < 0.001). In the test, our model showed good discrimination and calibration. The C-index, AUC, and Brier skill score were 0.857, 0.873, and 0.078, respectively.

Conclusions

Machine learning-based model could be used to predict the risk of HCC development based on the health screening examination results and claim data.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08498-w.

Sex disparities and adverse cardiovascular and kidney outcomes in patients with chronic kidney disease: results from the KNOW-CKD

AIMS

Longitudinal studies of the association between sex and adverse clinical outcomes in patients with chronic kidney disease (CKD) are scarce. We assessed whether major outcomes may differ by sex among CKD patients.

METHODS

We analyzed a total of 1780 participants with non-dialysis CKD G1-5 from the KoreaN cohort study for Outcome in patients with Chronic Kidney Disease (KNOW-CKD). The primary outcome was a composite of non-fatal cardiovascular events or all-cause mortality. Secondary outcomes included fatal and non-fatal cardiovascular events, all-cause mortality, and a composite kidney outcome of ≥ 50% decline in estimated glomerular filtration rate from baseline or the onset of end-stage kidney disease.

RESULTS

There were 1088 (61%) men and 692 (39%) women in the study cohort. The proportion of smokers was significantly higher in men (24% vs. 3%). During 8430 person-years of follow-up, 201 primary outcome events occurred: 144 (13%) in men and 57 (8%) in women, with corresponding incidence rates of 2.9 and 1.7 per 100 person-years, respectively. In multivariable Cox models, men were associated with a 1.58-fold (95% CI 1.06-2.35) higher risk of composite outcome. Propensity score matching analysis revealed similar findings (HR 1.81; 95% CI 1.14-2.91). Risk of all-cause mortality was significantly higher in men of the matched cohort. However, there was no difference in the risk of CKD progression. In the subgroup with coronary artery calcium (CAC) measurements, men had a higher likelihood of CAC progression.

CONCLUSIONS

In Korean CKD patients, men were more likely to experience adverse cardiovascular events and death than women.

Sudden cardiac death related to physical exercise and sports in the young: a nationwide cohort study of Australia

Funding Acknowledgements

Type of funding sources: None.

Background

Sudden cardiac death (SCD) during physical exercise is uncommon but devastating.

Purpose

We aimed to determine risk factors, causes and circumstances of sports and exercise-related SCD in the young in Australia.

Methods

We retrospectively reviewed the National Coronial Information System (NCIS) registry for deaths in Australia relating to cardiovascular disease (CVD) in cases aged 10 to 35 years between 2000-2016. Included cases had been undertaking sports or physical exercise at time of event. We collected baseline demographics and circumstances of death including location, type of physical exercise, whether the event was witnessed, and engagement of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use prior to ambulance arrival.

Results

Over a 17-year period, 1,925 SCD cases were identified of which 110 cases (6%) related to sports/physical exercise were included in final analysis. Median age was 27 years (interquartile range [IQR] 21-32 years) with most being male (92%). Median BMI was 27 kg/m2 (IQR, 23-30) with 13 cases (12%) occurring in active athletes. Most common causes were coronary artery disease (CAD; 37%) and sudden arrhythmic death syndrome (SADS; 20%). Australian Rules Football (24%), running/jogging (14%) and soccer (14%) were the most frequently practiced at time of event. Prior symptoms were present in 39% (chest pain 37%, presyncope/syncope 26%). Most were witnessed (87%) with bystander CPR in 70%. AED use prior to ambulance arrival was 8%.

Conclusions

This study demonstrates the high occurrence of CAD and SADS in exercise-related SCD in the young. Although events were commonly witnessed, an AED was seldom used prior to ambulance arrival highlighting an important opportunity to improve outcomes in the post-arrest chain of survival.

Incidence and prevalence of systemic lupus erythematosus among Korean women in childbearing years: A nationwide population-based study

BACKGROUND

Most women with systemic lupus erythematosus (SLE) are diagnosed with the disease in their reproductive years, but the incidence and prevalence of SLE among women of childbearing age have not been studied. The objective of this study was to estimate the incidence and prevalence of SLE among the Korean women of childbearing age.

METHODS

Women aged 20 to 44 years with SLE were identified from National Health Insurance Service - National Health Information Database (2009-2016), which contain health information of approximately 97% of the Korean population. SLE was defined by International Classification of Diseases, 10th revision code, M32. Incidence and prevalence were calculated per 100,000 person-years and stratified by year and age.

RESULTS

A total of 12,756 women with SLE were identified. The incidence of SLE from 2011 to 2016 among women in childbearing years was 8.18/100,000 person-years (95% CI 7.94-8.43), with the highest incidence in 2016 (8.56/100,000 person-years, 95% CI 7.95-9.17) and the lowest incidence in 2012 (7.85/100,000 person-years, 95% CI 7.28-8.42). The prevalence of SLE from 2009 to 2016 among women in childbearing years was 77.07/100,000 person-years (95% CI 75.76-78.39), with the highest prevalence in 2014 (79.47/100,000 person-years, 95% CI 77.64-81.30) and the lowest in 2010 (74.19/100,000 person-years, 95% CI 72.45-75.93). The peak age for SLE incidence was between 25-39 years, and lower incidence was seen in the early (20-24 years) and late (40-44 years) childbearing age periods. There was an increasing trend in prevalence according to age in women of childbearing age, with the highest prevalence occurring in the 40-44 age group.

CONCLUSIONS

The risk and burden of SLE are high among women during their childbearing years. This calls for special attention to this particular population group when allocating health resources.

Effects of Adenoidectomy and Adenotonsillectomy on Tympanostomy Tube Reinsertion Based on Korean Population-Based National Sample Cohort Data

OBJECTIVES

We evaluated the effects of adenoidectomy and adenotonsillectomy (AT) on tympanostomy tube (TT) reinsertion using population-based retrospective cohort data to confirm the association of adenoidectomy or AT with TT reinsertion reported in several previous studies.

MATERIALS AND METHODS

This study used data from the National Health Insurance Service National Sample Cohort in Korea. We selected patients who underwent TT insertion between the ages of 0 and 9 years from 2006 to 2015. Patients were divided into the following groups: group 1, TT insertion only; group 2, TT insertion with adenoidectomy; and group 3, TT insertion with AT. The number of TT reinsertions was analyzed.

RESULTS

There were 745 patients in group 1, 115 in group 2, and 251 in group 3. There were 1,019 cases of total TT insertion and 336 of reinsertion in group 1, 169 of total TT insertion and 31 of reinsertion in group 2, and 343 of total TT insertion and 50 of reinsertion in group 3. The rates of TT reinsertion were significantly lower in groups 2 and 3 than in group 1. The risks of TT reinsertion in groups 2 and 3 were significantly lower than the risk in group 1 in both univariate and multivariate Cox regression analysis.

CONCLUSION

TT reinsertion was significantly lower in the TT insertion with adenoidectomy and TT insertion with AT groups than in the TT insertion only group. We confirmed the effects of adenoidectomy and AT on reduction of the rate of repeated TT insertion by analysis of population-based data.

Machine learning prediction for mortality of patients diagnosed with COVID-19: a nationwide Korean cohort study

The rapid spread of COVID-19 has resulted in the shortage of medical resources, which necessitates accurate prognosis prediction to triage patients effectively. This study used the nationwide cohort of South Korea to develop a machine learning model to predict prognosis based on sociodemographic and medical information. Of 10,237 COVID-19 patients, 228 (2.2%) died, 7772 (75.9%) recovered, and 2237 (21.9%) were still in isolation or being treated at the last follow-up (April 16, 2020). The Cox proportional hazards regression analysis revealed that age > 70, male sex, moderate or severe disability, the presence of symptoms, nursing home residence, and comorbidities of diabetes mellitus (DM), chronic lung disease, or asthma were significantly associated with increased risk of mortality (p ≤ 0.047). For machine learning, the least absolute shrinkage and selection operator (LASSO), linear support vector machine (SVM), SVM with radial basis function kernel, random forest (RF), and k-nearest neighbors were tested. In prediction of mortality, LASSO and linear SVM demonstrated high sensitivities (90.7% [95% confidence interval: 83.3, 97.3] and 92.0% [85.9, 98.1], respectively) and specificities (91.4% [90.3, 92.5] and 91.8%, [90.7, 92.9], respectively) while maintaining high specificities > 90%, as well as high area under the receiver operating characteristics curves (0.963 [0.946, 0.979] and 0.962 [0.945, 0.979], respectively). The most significant predictors for LASSO included old age and preexisting DM or cancer; for RF they were old age, infection route (cluster infection or infection from personal contact), and underlying hypertension. The proposed prediction model may be helpful for the quick triage of patients without having to wait for the results of additional tests such as laboratory or radiologic studies, during a pandemic when limited medical resources must be wisely allocated without hesitation.

Association between Body Mass Index and Risk of COVID-19: A Nationwide Case-Control Study in South Korea

Background

Increased body mass index (BMI) has been associated with higher risk of severe coronavirus disease 2019 (COVID-19) infections. However, whether obesity is a risk factor for contracting COVID-19 has been hardly investigated so far.

Methods

We examined the association between BMI level and the risk of COVID-19 infection in a nationwide case-control study comprised of 3,788 case patients confirmed with COVID-19 between January 24 and April 9, 2020 and 15,152 controls matched by age and sex, who were aged 20 years or more and underwent National Health Insurance Service (NHIS) health examinations between 2015−2017, using data from the Korean NHIS with linkage to the Korea Centers for Disease Control and Prevention data. Our primary exposure of interest was BMI level categorized into four groups; &18.5 (underweight), 18.5-22.9 (normal weight), 23-24.9 (overweight), and ≥25 kg/m ² (obese).

Results

Of the entire 18,940 study population, 11,755 (62.1%) were women, and the mean (SD) age of the study participants was 53.7 (13.8) years. In multivariable logistic regression models adjusted for sociodemographic, comorbidity, laboratory and medication data, there was a graded association between higher BMI levels and higher risk of COVID-19 infection; compared to normal weight individuals, the adjusted ORs in the overweight and obese individuals were 1.13 (95% CI, 1.03-1.25) and 1.26 (95% CI, 1.15-1.39), respectively. This association was robust across age and sex subgroups.

Conclusions

Higher BMI levels were associated with higher risk of contracting COVID-19.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Associations of Systolic Blood Pressure With Incident CKD G3-G5: A Cohort Study of South Korean Adults

RATIONALE & OBJECTIVE

Clinical practice guidelines recommend a target blood pressure (BP)<130/80 mm Hg to reduce cardiovascular risk. However, the optimal BP to prevent chronic kidney disease (CKD) is unknown.

STUDY DESIGN

Population-based retrospective cohort study.

SETTING & PARTICIPANTS

10.5 million adults who participated in the National Health Insurance Service National Health Checkup Program in South Korea between 2009 and 2015 and had an estimated glomerular filtration rate (GFR) ≥ 60 mL/min/1.73 m² at the beginning of follow-up.

PREDICTORS

Baseline and time-updated systolic BP (SBP) as a continuous variable and categorized as<110, 110 to 119, 120 to 129, 130 to 139, or≥140 mm Hg.

OUTCOME

Incident CKD GFR categories 3 to 5 (CKD G3-G5), defined as de novo development of estimated GFR<60 mL/min/1.73 m² for at least 2 consecutive assessments confirmed at least 90 days apart.

ANALYTICAL APPROACH

Cox proportional hazards regression for baseline BP and marginal structural analysis for time-updated BP.

RESULTS

During 49,169,311 person-years of follow-up, incident CKD G3-G5 developed in 172,423 (1.64%) individuals with a crude event rate of 3.51 (95% CI, 3.49-3.52) per 1,000 person-years. Compared to a baseline SBP of 120 to 129 mm Hg, HRs for incident CKD G3-G5 for the<110, 110 to 119, 130 to 139, and≥140 mm Hg categories were 0.84 (95% CI, 0.82-0.85), 0.92 (95% CI, 0.91-0.94), 1.11 (95% CI, 1.09-1.12), and 1.30 (95% CI, 1.28-1.31), respectively. For time-updated SBPs, corresponding HRs were 0.57 (95% CI, 0.56-0.59), 0.79 (95% CI, 0.78-0.80), 1.58 (95% CI, 1.55-1.60), and 2.49 (95% CI, 2.45-2.53), respectively. Treated as a continuous exposure, each 10-mm Hg higher SBP was associated with 35% higher risk for incident CKD G3-G5 (95% CI, 1.35-1.36).

LIMITATIONS

Use of International Classification of Diseases codes to assess comorbid condition burden; residual confounding, and potential selection bias cannot be excluded.

CONCLUSIONS

In this large national cohort study, higher SBPs were associated with higher risk for incident CKD G3-G5. These findings support evaluation of SBP-lowering strategies to reduce the development of CKD.

Machine learning prediction of incidence of Alzheimer's disease using large-scale administrative health data

Nationwide population-based cohort provides a new opportunity to build an automated risk prediction model based on individuals' history of health and healthcare beyond existing risk prediction models. We tested the possibility of machine learning models to predict future incidence of Alzheimer's disease (AD) using large-scale administrative health data. From the Korean National Health Insurance Service database between 2002 and 2010, we obtained de-identified health data in elders above 65 years (N = 40,736) containing 4,894 unique clinical features including ICD-10 codes, medication codes, laboratory values, history of personal and family illness and socio-demographics. To define incident AD we considered two operational definitions: "definite AD" with diagnostic codes and dementia medication (n = 614) and "probable AD" with only diagnosis (n = 2026). We trained and validated random forest, support vector machine and logistic regression to predict incident AD in 1, 2, 3, and 4 subsequent years. For predicting future incidence of AD in balanced samples (bootstrapping), the machine learning models showed reasonable performance in 1-year prediction with AUC of 0.775 and 0.759, based on "definite AD" and "probable AD" outcomes, respectively; in 2-year, 0.730 and 0.693; in 3-year, 0.677 and 0.644; in 4-year, 0.725 and 0.683. The results were similar when the entire (unbalanced) samples were used. Important clinical features selected in logistic regression included hemoglobin level, age and urine protein level. This study may shed a light on the utility of the data-driven machine learning model based on large-scale administrative health data in AD risk prediction, which may enable better selection of individuals at risk for AD in clinical trials or early detection in clinical settings.

Association Between Income Disparities and Risk of Chronic Kidney Disease: A Nationwide Cohort Study of Seven Million Adults in Korea

OBJECTIVE

To examine the association between income level and incident chronic kidney disease (CKD) in adults with normal baseline kidney function.

PATIENT AND METHODS

We studied the association between income level categorized into deciles and incident CKD in a national cohort comprised of 7,405,715 adults who underwent National Health Insurance Service health examinations during January 1, 2009, to December 31, 2015, with baseline estimated glomerular filtration rates (eGFRs) ≥60 mL/min/1.73 m². Incident CKD was defined as de novo development of eGFR <60 mL/min/1.73 m² (model 1) or ≥25% decline in eGFR from baseline values accompanied by eGFR <60 mL/min/1.73 m² (model 2).

RESULTS

During a median follow-up of 4.8 years, there were 122,032 of 7,405,715 (1.65%) and 55,779 of 7,405,715 (0.75%) incident CKD events based on model 1 and 2 definitions, respectively. Compared with income levels in the sixth decile, there was an inverse association between lower income level and higher risk for CKD up to the fourth decile, above which no additional reduction (model 1) or slightly higher risk for CKD (model 2) was observed at higher income levels. The multivariable-adjusted hazard ratios from the lowest to fourth deciles were 1.30 (95% CI, 1.26-1.33), 1.16 (95% CI, 1.13-1.19), 1.07 (95% CI, 1.05-1.10), and 1.06 (95% CI, 1.03-1.09) in model 1 and 1.32 (95% CI, 1.27-1.37), 1.18 (95% CI, 1.14-1.22), 1.08 (95% CI, 1.04-1.13), and 1.05 (95% CI, 1.01-1.09) in model 2, respectively. These associations persisted across various subgroups of age, sex, and comorbidity status.

CONCLUSION

In this large nationwide cohort, lower income levels were associated with higher risk for incident CKD.