Health Insurance Service Research Articles

Atrial fibrillation fact sheet in Korea 2024 (part 1): epidemiology of atrial fibrillation in Korea

Background and objectivesThis study aimed to analyze and present updated trends in atrial fibrillation (AF) epidemiology within the Korean population, providing a foundation for planning and implementing appropriate management and treatment strategies for patients with AF.Patients and methodsWe used the Korean National Health Insurance Service database to evaluate the prevalence, incidence, comorbidities, and clinical adverse outcomes of patients with AF in Korea between 2013 and 2022.ResultsAF prevalence in Korean adults aged ≥ 20 years doubled (1.1 to 2.2%) between 2013 and 2022, with significant increases observed across various sex and age groups. Similarly, the number of newly diagnosed patients with AF per year increased steadily, with the incidence rising from 184 to 275 per 100,000 person-years, particularly among older populations. Over this period, the mean age of patients with AF increased from 67.7 to 70.3 years, and comorbidities prevalence and CHA2DS2-VASc score rose significantly, indicating a higher stroke risk. Compared with patients without AF, AF was associated with an increased risk of mortality (hazard ratio [HR]: 1.78), ischemic stroke (HR: 2.39), major bleeding (HR: 2.10), myocardial infarction (HR: 1.44), and heart failure admission (HR: 2.42).ConclusionAF prevalence and incidence have steadily increased between 2013 and 2022, with a more pronounced increase in older patients. Patients with AF are increasingly becoming a high-risk population and are at increased risk of clinical adverse outcomes compared to non-AF patients. Therefore, a sustained national effort to improve AF awareness and comprehensive care quality for patients with AF is required.

Incidence of Panic Disorder Diagnoses After Celebrity Disclosures of Panic Disorder in South Korea

The persistent stigma associated with mental health conditions is a major challenge worldwide. Celebrities may improve this by openly discussing their own mental health issues, potentially influencing public attitudes and encouraging individuals to seek treatment for these conditions. To evaluate the impact of celebrity mental health disclosures on the incidence and prevalence of panic disorder diagnosis in South Korea. This cohort study included the entire South Korean population from January 2004 to December 2021, as reflected in the National Health Insurance Service data. Analysis was conducted from May 2022 through January 2024. Time periods analyzed included the timeframe before (from January 2004 to December 2010) and after the public disclosures of panic disorder by 3 high-profile Korean celebrities between December 2010 and January 2012 (from January 2011 to December 2021). Monthly incidence and prevalence of panic disorder, defined by the presence of a clinical diagnosis of the condition. Trends were assessed using interrupted time series analysis with autoregressive integrated moving average models. To assess public interest in panic disorder, trends in search data were analyzed, examining the association between the timing of increased searches and changes in the incidence and prevalence of panic disorder. Data on obsessive-compulsive disorder (OCD) were included as a control. The study covered the entire population of South Korea, including 48 559 946 individuals in January 2004 and 52 593 886 individuals in December 2021. Before 2011, the mean (SD) annual prevalence of panic disorder was stable at 560 (140) persons per 100 000 persons per year. The celebrity disclosure in December 2010 was associated with higher monthly incidence rates of panic disorder, as measured by insurance claims data, changes that were observed in both the level (5.8 persons; 95% CI, 2.2-9.5 persons) and slope (0.78 persons per month; 95% CI, 0.19-1.40 persons per month) per 100 000 persons. By 2021, the observed annual prevalence per 100 000 persons reached 7530 persons, an increase of 775.6% compared with the 860 persons (95% CI, 330-1400 persons) estimated if the disclosures had not occurred. Internet searches anticipated changes in monthly prevalence with a lag of 2 or 3 months (F = 4.26, P = .02 and F = 3.11, P = .03, respectively). The celebrity disclosures had no significant association with the incidence or prevalence of OCD. In this observational cohort study, celebrity disclosure of mental health conditions was associated with a sustained reduction in stigma, as reflected in increased help-seeking behavior for the condition over more than a decade. This underscores the influential role celebrities can play in shaping public health perceptions and behaviors, offering valuable insights for the development of future mental health policies and public awareness campaigns.

Trends in alcohol use and alcoholic liver disease in South Korea: a nationwide cohort study

BackgroundThere is a lack of national-level research on alcohol consumption and the epidemiology of alcoholic liver disease (ALD) in South Korea. This study aims to address the critical public health issue of ALD by focusing on its trends, incidence, and outcomes, using nationwide claims data.MethodsUtilizing National Health Insurance Service data from 2011 to 2017, we calculated the population's overall drinking amount and the incidence of ALD based on ICD-10 diagnosis codes.ResultsFrom 2011 to 2017 in South Korea, social drinking increased from 15.7% to 16.5%, notably rising among women. High-risk drinking remained around 16.4%, decreasing in men aged 20–39 but not decreased in men aged 40–59 and steadily increased in women aged 20–59. The prevalence of ALD in high-risk drinkers (0.97%) was significantly higher than in social drinkers (0.16%). A 3-year follow-up revealed ALD incidence of 1.90% for high-risk drinkers and 0.31% for social drinkers. Women high-risk drinkers had a higher ALD risk ratio (6.08) than men (4.18). The economic burden of ALD was substantial, leading to higher healthcare costs and increased hospitalization. Progression rates to liver cirrhosis and hepatocellular carcinoma (HCC) in ALD patients were 23.3% and 2.8%, respectively, with no gender difference in cirrhosis progression.ConclusionsThe study revealed a concerning rise in alcohol consumption among South Korean women and emphasizes the heightened health risks and economic burdens associated with high-risk drinking, especially concerning ALD and its complications.

Attention-deficit/hyperactivity disorder and subsequent diagnoses of major psychiatric disorders: a nationwide population-based study.

We evaluated the risk of being diagnosed with various psychiatric disorders after an attention-deficit/hyperactivity disorder (ADHD) diagnosis using data from South Korea's National Health Insurance Service from 2002 to 2019, which covers approximately 97% of the country's population. ADHD and control groups were selected after propensity score matching was performed for individuals diagnosed with ADHD and their age- and sex-matched counterparts from the general population. Comorbid psychiatric disorders included depressive disorder, bipolar disorder, tic disorder, and schizophrenia. The incidence of newly diagnosed psychiatric disorders was compared between the groups. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated and adjusted for ADHD medication prescription. After matching, 353,898 individuals were assigned to each of the two groups. Compared to the control group, the ADHD group showed a significantly higher risk of being subsequently diagnosed with depressive disorder, bipolar disorder, schizophrenia, and tic disorder. The onset age of depressive disorder, bipolar disorder, and schizophrenia in the ADHD group was 16-17 years, approximately 5 years earlier than that in the control group. The risk for depression was the highest in individuals with high income levels, and that for schizophrenia was the highest among rural patients. The median length of the follow-up time until the diagnosis of each comorbid psychiatric disorder was 7.53, 8.43, 8.53, and 8.34 years for depressive disorder, bipolar disorder, schizophrenia, and tic disorder, respectively. Individuals with ADHD had an overall higher risk of being diagnosed with subsequent psychiatric disorders than did the controls. Hence, they should be carefully screened for other psychiatric symptoms from an early age and followed up for an extended duration, along with appropriate interventions for ADHD symptoms, including psychosocial treatments and educational approaches.

Endorsed midwife prescribing in Australia: “[For] the women, more than anything”

ProblemPrescribing by Endorsed Midwives has existed in Australia for more than ten years. Significant barriers exist in the bureaucracy surrounding prescribing and state and territory legislation which further constrain midwives capacity to prescribe required medications. BackgroundCurrent evidence indicates Endorsed Midwives improve timely access to medications and can experience both enablers and barriers to prescribing. AimTo explore Endorsed Midwives’ lived experiences of medication prescribing, including which medications are being prescribed, how this affects the women in their care, midwives’ practice, and perspectives on the future of midwifery prescribing. MethodsA descriptive qualitative approach was used. Data collection occurred through semi-structured interviews (n=10) of Endorsed Midwives from varied Australian practice contexts and locations. Data analysis followed Reflexive Thematic Analysis. FindingsFour themes were developed: Medication prescription as essential healthcare; Prescribing optimises midwifery practice; External structures can both promote and inhibit the capacity to prescribe; The future of prescribing. DiscussionEndorsed Midwife prescribing has the potential to positively impact women’s maternity care and enable midwives to fulfil their scope of practice. However, limitations to prescribing need to be addressed to capitalise on these benefits. ConclusionSignificant reform of health service policy, state and territory legislation and further development of the Pharmaceutical Benefits Scheme are required to fully embrace and capitalise on the full scope of Endorsed Midwives in the Australian Healthcare system.

The Impact of Transcatheter Aortic Valve Implantation on Health Care Costs and Clinical Outcomes Based on Frailty Risk: A Nationwide Cohort Analysis

BackgroundTranscatheter aortic valve implantation (TAVI) is preferred for treating severe aortic stenosis in older, frail populations, yet the impact of frailty on economic and clinical outcomes of TAVI is not well studied. MethodsThis retrospective cohort study included 2175 TAVI patients from 2015 to 2019, using Korea's National Health Insurance Service database, stratifying patients into low, intermediate, and high-frailty groups, using the Hospital Frailty Risk Score (HFRS). Health care costs, admissions, and total length of hospitalization were analyzed using Wilcoxon-rank test 12 months pre- and post-TAVI. Composite endpoint of death, stroke, and major bleeding, with individual outcomes, were compared using χ2 tests and Kaplan-Meier analysis. ResultsMean age was 80.2 years, and 47.3% were male; 747 (34.3%) were low frailty, 1159 (53.3%) were moderate frailty, and 269 (12.4%) were high frailty. After TAVI, medical costs decreased in the intermediate- (pre-TAVI: 2,269,000 KRW [$1668 USD], post-TAVI: 1,607,000 KRW [$1181 USD]; P < 0.001) and high-frailty groups (pre-TAVI: 3,949,000 KRW [$2904 USD], post-TAVI: 2,188,000 KRW [$1609 USD]; P < 0.001). All frailty groups had shorter length of hospital stay post-TAVI (26 to 21 days in the low-frailty, 44 to 31 days in the intermediate-frailty, and 65 to 41 days in the high-frailty group; all P <0.001). The composite outcome was higher in the frailer groups (27.8% in the low-frailty vs 31.5% in the intermediate-frailty vs 37.9% in the high-frailty group; P = 0.008). All groups showed comparable rates of cardiovascular death, stroke, or bleeding. ConclusionsTAVI is clinically viable and cost-saving treatment option for frail patients with severe aortic stenosis.

Risk of pulmonary embolism and deep vein thrombosis following COVID-19: a nationwide cohort study.

Recent studies elucidate that coronavirus disease 2019 (COVID-19) patients may face a higher risk of cardiovascular complications. This study aimed to evaluate association of COVID-19 with the risk of pulmonary embolism (PE) or deep vein thrombosis (DVT). This nationwide population-based retrospective cohort study included Korean adult citizens between January 2021 and March 2022 from the Korea Disease Control and Prevention Agency COVID-19 National Health Insurance Service cohort. The Fine and Gray's regression with all-cause death as a competing event was adopted to evaluate PE and DVT risks after COVID-19. This study included a total of 1,601,835 COVID-19 patients and 14,011,285 matched individuals without COVID-19. The risk of PE (adjusted hazard ratio [aHR], 6.25; 95% confidence interval [CI], 3.67-10.66; p<0.001) and DVT (aHR, 3.05; 95% CI, 1.75-5.29; p<0.001) was higher in COVID-19 group in individuals without complete COVID-19 vaccination. In addition, individuals with complete COVID-19 vaccination still had a higher risk of COVID-19-related PE (aHR, 1.48; 95% CI, 1.15-1.88; p<0.001). However, COVID-19 was not a significant risk factor for DVT among those with complete COVID-19 vaccination. COVID-19 was identified as an independent factor that elevated PE and DVT risks, especially for individuals without complete COVID-19 vaccination.

Increased risk of developing cerebro-cardiovascular diseases in police officers: a nationwide retrospective cohort study

BackgroundPolice officers face an increased risk of developing cerebro-cardiovascular diseases (CVD). However, current literature lacks population-based cohort studies specifically focusing on this association. This study aimed to investigate the association between police officers and the risk of developing CVD compared with education officers, while accounting for socioeconomic and demographic factors.MethodsWe used the Korean National Health Insurance Service data spanning from 2009 to 2020. In this population-based retrospective matched cohort study, we identified age, sex, and calendar years of job-enrollment–matched education officers for each police officer. This study evaluated the CVD occurrence, including acute myocardial infarction, ischemic stroke, and hemorrhagic stroke. Using multivariable Cox regression analysis, we determined the risk of developing CVD, expressed as a hazard ratio (HR) and 95% confidence interval (CI).ResultsAmong 104,134 police officers and 104,134 education officers, 4,391(42.2%) cases and 3,631(34.9%) cases of CVD occurred, respectively. The mean ± standard deviation age was 38.4 ± 9.4 years in police officers and 38.6 ± 9.5 years in education officers. The proportion of men was 84.8 % in both groups. Police officers were significantly associated with a higher risk of developing CVD compared with education officers, with an adjusted HR of 1.15 (95% CI, 1.09–1.22). In addition, police officers had significantly higher risks for acute myocardial infarction (adjusted HR, 1.16; 95% CI, 1.06–1.26) and ischemic stroke (adjusted HR, 1.17; 95% CI, 1.09–1.25).ConclusionsThe findings of our study highlight a significant increase in the risk of developing CVD among police officers, particularly among those aged 45 years and older and those with uncontrolled blood pressure compared to their education officer counterparts. Future cohort studies are required to confirm this association.

Comparing Costs and Healthcare Resource Utilization (HCRU) Using LAMA versus LABA/ICS at Treatment Initiation for COPD: Findings from CITRUS (Comparing the Incidence of Tiotropium and ICS/LABA in Real-World Use in South Korea) Study.

COPD causes substantial economic burden on healthcare. Alternative treatment strategies for COPD can be associated with different costs dependent upon their relative safety and effectiveness. We compared costs and healthcare resource utilization (HCRU) associated with LAMA or LABA/ICS initiation. Using the Korean National Health Insurance Service database, we enrolled COPD patients initiating treatment with LAMA or LABA/ICS between January 2005 and April 2015. Propensity score matched individuals were compared on all-cause and COPD-related medical costs and HCRU over a three-year follow-up period. A total of 2444 patients were enrolled in each treatment group. LAMA group was associated with significantly lower costs than LABA/ICS group, both in all-cause (403.08 vs 474.50 USD per patient per month [PPPM], cost ratio 1.18, 95% confidence interval [CI]=1.10-1.26, p<0.0001) and COPD-related (216.37 vs 267.32 USD PPPM, cost ratio 1.24, 95% CI=1.13-1.35, p<0.0001) medical costs. All-cause HCRU was not significantly different between groups, while COPD-related HRCU was higher in LAMA group (0.66 vs 0.60 medical visits PPPM, p<0.0001). COPD patients initiating treatment with LAMA were associated with lower all-cause and COPD-related medical costs than those starting with LABA/ICS despite the similar all-cause HCRU and higher COPD-related HCRU. Initiation with LAMA is a cost-efficient option for the treatment of COPD.

Association between Systolic Blood Pressure Variability and Incident Aortic Stenosis.

Background: This study investigated the potential link between blood pressure variability (BPV) and the incidence of aortic stenosis (AS) using Korean National Health Insurance Service data from 2002 to 2019. Methods: We collected annual systolic blood pressure variability (SBPV) measurements consisting of three consecutive blood pressure readings each year over three years. The obtained SBPV data was divided into five quantiles, with the highest quintile representing a high fluctuation of blood pressure. Results: Analyzing 9,341,629 individuals with a mean age of 40.7 years, the study found 3981 new AS diagnoses during an average 8.66-year follow-up. Independent predictors for AS included higher blood pressure levels and elevated systolic blood pressure variability (SBPV). The hazard ratios (HR) for different SBPV quintiles compared to the reference (1st quintile) were as follows: 2nd quintile HR 1.09 (p = 0.18), 3rd quintile HR 1.13 (p = 0.04), 4th quintile HR 1.13 (p = 0.04), and 5th quintile HR 1.39 (p < 0.001). Conclusion: Our findings suggest that both hypertension and high fluctuations in SBP during consecutive visits are associated with an increased risk of incident AS. These results emphasize the importance of blood pressure management and stability in the prevention of AS.

4대 공적연금의 연령별 사망률 데이터 구축에 관한 연구

In this study, we aimed to address the issue of not reflecting the characteristics of each public pension system by constructing data on mortality rates by age group for the four public pensions, which had not been established before. To do this, we utilized NHID from National Health Insurance Service and estimated values from statistical yearbooks of the four public pension agencies, along with data obtained through information disclosure requests. Successfully, we constructed mortality rate data by age group. During the data construction process, issues such as data integration and correction arose, which were addressed using statistical methods. Using the constructed data, we compared the life tables of five groups: subscribers and recipients of the four major public pensions, and non-subscribers, for the years 2011 to 2018, and compared life expectancies. The comparison results showed that overall, the order of average life expectancy was non-participants ≤ National Pension ≤ Government employee Pension ≤ Military Pension ≤ Teachers Pension participants and recipients, with significant differences observed. This study is the first in Korea to construct mortality rate data by age group for the four public pensions, which could serve as a foundational dataset for new fiscal projections of public pensions, contributing to addressing issues related to public pension reform.

NSSF Social Health Insurance Benefit (SHIB) and Health Care Services: Accessibility and Availability in Tanzania

This study is about “Social Health Insurance and accessibility of health care services through National Social Security Fund (NSSF) Health Insurance service in Kinondoni Municipality. The focus of this study was on the ease of accessing health services using the NSSF health insurance, and the beneficiaries’ awareness level since people knew about NHIF and ICHF only. The objective of the study is to examine the accessibility of Social Health Insurance Benefits on health care service to people at Kinondoni Municipality. The study used a qualitative research approach to gather and analyze data from informants. In-depth interview was used to capture information from the key informants; observation was used to supplement and understand information gathered from the perspective group studied. This study used conventional theory to signify that any additional health care that consumers purchased through insurance coverage was not worth the real cost of producing it. The results indicated that Health Insurance users have failed to use it due to its accessibility and ignorance of community members and insufficient funds released by the National Social Security Fund (NSSF) to cover all the services required by their customers. This paper recommends that it is important to maintain the quality of healthcare services that NSSF receives from its customers. Also, NSSF should be accessible and reliable to all its customers.

Risk of lung diseases in patients with previous carbon monoxide poisoning: a nationwide population-based cohort study in the Republic of Korea

Introduction Carbon monoxide poisoning is associated with severe damage to various organs. In this study, we aimed to determine if previous carbon monoxide poisoning was associated with an increased risk of lung diseases. Methods The study population was derived from the National Health Insurance Service database of Korea between 1 January 2002 and 31 December 2021. Adults with carbon monoxide poisoning, with at least one visit to medical facilities between 2002 and 2021, were included. For comparison, an equal number of matched controls with the same index date were selected from the database. Results A total of 28,618 patients with carbon monoxide poisoning and 28,618 matched controls were included in this study. Approximately 42.8 per cent of the patient and control groups were female, with a mean age of 51.3 years. In patients with carbon monoxide poisoning, there was a significant increase in the risk of lung cancer (adjusted hazard ratio, 1.84; 95 per cent confidence interval, 1.42–2.39; P < 0.001), chronic obstructive pulmonary disease (adjusted hazard ratio, 1.60; 95 per cent confidence interval, 1.36–1.89; P < 0.001), pulmonary tuberculosis (adjusted hazard ratio, 1.46; 95 per cent confidence interval, 1.13–1.88; P = 0.003), and non-tuberculous mycobacterial infection (adjusted hazard ratio, 1.54; 95 per cent confidence interval, 1.01–2.36; P = 0.047). Discussion In this retrospective cohort study, previous carbon monoxide poisoning was associated with an increased risk of lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection. Further studies are needed to confirm such an association in other populations and the risk of lung diseases due to the toxic effect of carbon monoxide from different sources. Conclusions Previous carbon monoxide poisoning was associated with an increased risk of lung diseases, but the relative importance of the causes and sources of exposure was not known. The long-term management of survivors of acute carbon monoxide poisoning should include monitoring for lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection.

Prevalence of temporomandibular disorder in Korea: a nationwide population-based study

Purpose: Few studies have assessed the prevalence of temporomandibular disorders (TMD) in the Korean population.Methods: We used cohort data from the Korean National Health Insurance Service between 2012 and 2020. The data consisted of main diagnoses related to TMD (International Classification of Diseases 10th Revision [ICD-10] code: K07.6 and K07.6x). The age-standardized prevalence of TMD was calculated using the estimated Korean population in 2020 as a reference.Results: The age-standardized prevalence of TMD increased from 604 persons per 100,000 persons in 2012 to 869 persons in 2020. In 2020, the overall age-standardized prevalence was 1,355 persons in the 10 to 19 years age group, 1,809 persons in the 20 to 29 years age group, and 979 persons in the 30 to 39 years age group. The age-standardized prevalence was approximately 1.5 times higher in females than in males (698 persons in males vs. 1,040 persons in females). Among the specific TMD subtypes, the age-standardized prevalence of internal derangement of the temporomandibular joint and pain in the temporomandibular joint, not classified elsewhere, was higher than that of other specific TMDs.Conclusion: The overall age-standardized prevalence of TMD was higher in the 10s, 20s, and 30s age groups and in females between 2012 and 2020. The age-standardized prevalence of internal derangement of temporomandibular joint was the highest among specific TMD subtypes.

Validation of self-reported morbidities of the Korean Atomic Bomb Survivor Cohort.

This study aimed to evaluate the agreement of disease status collected through a survey of the Korean Atomic Bomb Survivor Cohort (K-ABC), compared with medical claim records from the Korean National Health Insurance Service (NHIS) database and the Korean Central Cancer Registry (KCCR). Data on the lifetime physician-diagnosed morbidities of 1,215 K-ABC participants were collected through an interviewer-administered questionnaire between 2020 and 2022. Survey data were linked to the NHIS and KCCR databases. Eleven diseases were included for validation. We evaluated the following indicators: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, the area under the curve (AUC), and the kappa coefficient. The mean (standard deviation) age was 62.1 (18.7) years, and 42.6% of the participants were aged ≥70 years. Hypertension and cataracts showed the highest prevalence rates (33.8% and 28.8%, respectively). Hypertension, diabetes, and cancer demonstrated high sensitivity (>0.8) and specificity (>0.9), whereas diabetes, cancer, myocardial infarction, angina pectoris, and asthma exhibited high accuracy (>0.9). In contrast, arthritis, allergic rhinitis, and asthma showed low sensitivity (<0.4) and kappa values (<0.3). In the participants aged ≥70 years, the kappa value was ≥0.4 for all diseases except arthritis, allergic rhinitis, and asthma. The results from this initial analysis showed relatively high agreement between the survey and NHIS/KCCR databases, especially for hypertension, diabetes, and cancer. Our findings suggest that the information on morbidities collected through the questionnaires in this cohort was valid for both younger and older individuals.

Graves' orbitopathy development in thyroid cancer patients: a 16-year nationwide cohort study in South Korea.

We aimed to investigate the prevalence, risk factors, and prognosis of Graves' orbitopathy (GO) in patients with thyroid cancer without a history of hyperthyroidism. This retrospective cohort study analysed a sample from the Korean National Health Insurance Service database, which included 1,137,861 subjects from 2002 through 2019. Patients diagnosed with thyroid cancer, without a history of hyperthyroidism, were identified according to the Korean Standard Classification of Disease codes. The study compared the type of surgery, dose of radioactive iodine (RAI), and daily average thyroid hormone dose between patients who developed GO after being diagnosed with thyroid cancer and those who did not develop GO. We analysed the course of GO and the type of treatment. A total of 8499 cancer patients without a history of hyperthyroidism were identified, among whom 7836 underwent thyroidectomy. Of those who underwent thyroidectomy, 12 developed GO postoperatively. Among the 663 patients who did not undergo thyroidectomy, none developed GO. The prevalence of GO among thyroid cancer patients was 0.14%. The GO group received a significantly higher total RAI dose than the non-GO group (p = 0.036). There were no significant differences in sex, age, type of surgery, rate of RAI treatment, or average thyroid hormone dose between the two groups. One of the 12 patients who developed GO required intravenous steroids. Although GO rarely develops in thyroid cancer patients without coexisting hyperthyroidism, the total RAI dose may increase its risk. Further research would help clarify GO's association with thyroid cancer.

Chronic periodontitis and risk of lung cancer: a nationwide cohort study.

The impact of long-term chronic periodontal conditions on the risk of lung cancer could not be accurately evaluated. Our aim was to provide more evidence on the connection between chronic periodontitis (CP) and lung cancer using a nationwide dataset. This study used data from the Korean National Health Insurance Service National Sample Cohort. We enrolled 72,658 individuals with CP (CP cohort) between 2005 and 2019 and 1:1 age- and sex-matched controls without CP (non-CP cohort). During the median follow-up period of 5.1 (interquartile range, 2.8-8.0) years, 0.56% (n = 405/72,658) of the CP cohort and 0.29% (n = 212/72,658) of the matched non-CP cohort developed lung cancer, with incidence rates of 8.3 and 4.5 per 10,000 person-years. The risk of incident lung cancer was significantly higher in the CP cohort than in the matched non-CP cohort (adjusted hazard ratio = 2.27, 95% confidence interval = 1.94-2.65). The risk of incident lung cancer was 2.45-fold and 2.10-fold higher in mild and moderate-to-severe CP cohorts than in the matched non-CP control. The risk of incident lung cancer was especially higher in the 40-59 age group, females, and never-smokers than their counterparts. We demonstrate that the risk of incident lung cancer is higher in individuals with CP than in those without. The risk of lung cancer was especially high in individuals with more severe CP, females, never-smokers, and obese populations.

Effect of gout and diabetic kidney disease on renal cancer development in Korea.

Chronic kidney disease (CKD) and gout are risk factors for renal cancer. We analysed the effects of comorbid diabetic kidney disease and gout on renal cancer. This retrospective cohort study enrolled 847884 patients with type 2 diabetes mellitus (T2DM) who underwent health assessments provided by the Korean National Health Insurance Service in 2009. Based on CKD occurrence (glomerular filtration rate <60ml/min/1.73m2) and gout (two outpatient visits or one hospitalization within 5years), patients were classified into four groups: CKD-Gout- (87.5%), CKD-Gout+ (2.5%), CKD+Gout- (9.3%) and CKD+Gout+ (0.7%). Patients with incident renal cancer (International Classification of Diseases code C64) were followed up until December 2018. Renal cancer was diagnosed in 2376 patients (0.3%). Renal cancer incidence increased in sequential order of CKD-Gout- [0.29/1000 person-years (PY), CKD+Gout- and CKD-Gout+ (0.44 and 0.48/1000 PY, respectively) and CKD+Gout+ (1.14/1000 PY). Comorbid gout increased renal cancer risk depending on CKD occurrence {hazard ratio [HR] 1.28 [95% confidence interval (CI) 1.04-1.58 among those without CKD; HR 1.95 [95% CI 1.45-2.63] among those with CKD; P-value for interaction=0.024}. The interaction was significant, particularly in men and patients with a shorter diabetes duration (<5years) and lesser medication use (no insulin or fewer than three classes of oral hypoglycaemic agents). CKD and gout individually contributed to renal cancer incidence, and the risk is further increased when gout coexists with CKD. Screening for gout and appropriate management of CKD at an early T2DM stage may be beneficial.

Association between Smoking Habit Changes and the Risk of Myocardial Infarction in Ischemic Stroke Patients: a Nationwide cohort study.

Smoking is a well-known risk factor for cardiovascular diseases, including myocardial infarction (MI) and ischemic stroke (IS). While the relationship between smoking and the risk of cardiovascular diseases is established, the impact of changing smoking habits post-IS on the risk of subsequent MI remains unclear. This study aims to elucidate the effects of alterations in smoking behavior following an IS diagnosis on the likelihood of experiencing an MI. Utilizing data from the Korean National Health Insurance Services Database, this nationwide population-based cohort study included 199,051 participants diagnosed with IS between January 2010 and December 2016. Smoking status was categorized based on changes in smoking habits before and after IS diagnosis. The association between changes in smoking behavior and the risk of subsequent MI was analyzed using multivariable Cox proportional hazard regression models. During a median follow-up of 4.17 person-years, a total of 5,734 (2.88%) patients were diagnosed with MI after IS. Smoking quitters (2.93%) or former smokers (2.47%) have a similar or lower rate of MI than the average, even if they have smoked cigarettes, while sustained smokers (3.46%) or new smokers (3.81%) have much higher rates of MI. Among sustained and new smokers, the risk of incident MI were significantly higher than never smokers (new smoker adjusted HR [aHR]: 1.496, 95% CI 1.262-1.774; sustained smoker aHR 1.494, 95% CI 1.361-1.641). Also, among the study participants, approximately two-thirds continued smoking after their IS diagnosis. Changing smoking habits after an IS diagnosis significantly influences the risk of subsequent MI. Specifically, continuing or starting to smoke after an IS diagnosis is associated with a higher risk of MI. These results underscore the importance of targeted smoking cessation interventions for stroke patients to reduce the risk of subsequent myocardial infarction.

Association between depression and young-onset dementia in middle-aged women

BackgroundDementia is associated with older adults; however, it can also affect younger individuals, known as young-onset dementia (YOD), when diagnosed before the age of 65 years. We aimed to conduct a retrospective cohort study involving middle-aged women to investigate the association between premorbid depression and YOD development.MethodsWe included 1.6 million women aged 40–60 years who underwent health checkups under the Korean National Health Insurance Service and investigated the association between depression and YOD.ResultsWomen with depression had a significantly higher risk of developing YOD than women without depression. Among premenopausal women, those with depression had a 2.67-fold increased risk, whereas postmenopausal women with depression had a 2.50-fold increased risk. Late age at menarche (> 16 years) and young age at menopause (< 40 years) was associated with an increased risk of YOD.ConclusionsDepression in middle-aged women is a significant risk factor for the development of YOD. Understanding the role of reproductive factors can aid in the development of targeted therapeutic interventions to prevent or delay YOD.