Korean National Health Insurance Service Research Articles

Risk of cardiocerebrovascular diseases is increased in Korean women with polycystic ovary syndrome: a nationwide cohort study

To investigate the relationship between polycystic ovary syndrome (PCOS) and risk of cardiocerebrovascular disease in Korean women. This longitudinal cohort study using data from the Korean National Health Insurance Service included the women aged 15–44 years diagnosed with PCOS between 2002 and 2019, and the controls were matched 1:3 by age group, income, and region of residence. The endpoint outcomes of this study were the occurrence of ischemic heart disease, cerebrovascular diseases, and combined cardiocerebrovascular diseases in the PCOS and control groups. A stratified Cox proportional hazards regression analysis for matched data was performed to evaluate the relative hazard of events in the PCOS group compared to that in the control group. Among a total of 549,400 participants in the cohort, 137,416 women had a diagnosis of PCOS and 412,118 women did not have it. During a median follow-up of 54 months (interquartile range, 30–78 months), the incidence rates of all cardiovascular, ischemic heart, and cerebrovascular diseases were 6.6, 4.0, and 2.9, respectively, per 1000 person-years for women with PCOS, and 4.8, 2.8, and 2.3, respectively, per 1000 person-years for healthy control women. Women with PCOS had a higher hazard ratio of 1.224 (95% confidence interval, 1.18–1.27) of the composite cardiocerebrovascular diseases than those in the controls after propensity score matching for confounding variables, including body mass index, diabetes mellitus, hypertension, dyslipidemia, physical exercise level, alcohol consumption, current smoking, systolic and diastolic blood pressures, total cholesterol, and triglyceride levels. Hazard ratio for ischemic heart and cerebrovascular diseases was higher in women with PCOS than in the control group (hazard ratio, 1.254; 95% confidence interval, 1.20–1.31 and hazard ratio, 1.201; 95% confidence interval, 1.14–1.27, respectively). PCOS is associated with an increased risk of cardiocerebrovascular diseases in Korean women irrespective of their obesity. Counselling on the management of long-term risk of cardiovascular diseases should be offered to women with PCOS in East Asian countries where PCOS is characterized by a relatively low BMI.

Visit-to-visit variability in blood pressure and the risk of open-angle glaucoma in individuals without systemic hypertension: a nationwide population-based cohort study.

We aimed to evaluate the effect of visit-to-visit variability in blood pressure (BP) on the risk of open-angle glaucoma (OAG) in individuals without systemic hypertension using a population-based retrospective cohort study design. The Korean National Health Insurance Service-National Health Screening Cohort database, which collected data of 209,226 individuals between 2002 and 2015, was used to analyze the data of 140,910 eligible participants. The mean follow-up duration was 8.3 years. Visit-to-visit BP variability was assessed using standard deviation (SD), coefficient of variation (CV), and variability independent of the mean (VIM). Participants were categorized into four groups according to BP variability quartiles. We verified the effect of BP variability by comparing participants of the first to third quartiles of BP variability groups with those belonging to the fourth quartile group. A Cox proportional hazards model was used to determine the hazard ratio (HR) of BP variability in cases of newly diagnosed OAG. Moreover, we conducted subgroup analyses using baseline characteristics. In the multivariable analyses, BP variability did not significantly increase the risk of OAG development. However, subgroup analyses revealed significant interactions between age and systolic BP variability in the development of OAG (CV: p = 0.008; SD: p = 0.007). For participants aged <60 years, the risk of OAG development significantly increased with high systolic BP variability (CV: HR, 1.18; 95% confidence interval [CI], 1.00-1.39; p = 0.049). We observed a similar trend using the SD and VIM as the parameters for systolic BP variability. Higher visit-to-visit systolic BP variability was associated with an increased risk of OAG development in participants younger than 60 years of age without systemic hypertension. These results suggest that BP variability can be the considerable factor when assessing the risk of OAG, especially in relatively young people without systemic hypertension.

Cumulative exposure to impaired fasting glucose and gastrointestinal cancer risk: A nationwide cohort study.

Impaired fasting glucose (IFG) is associated with the risk of various cancers, but the cumulative effect of IFG on gastrointestinal cancer risk remains unclear. This study evaluated the association between the cumulative exposure to IFG and gastrointestinal cancer risk. The authors extracted data from the Korean National Health Insurance Service and health examination data sets. Among individuals ≥40 years old who were free of diabetes or cancer, 1,430,054 who underwent national health examinations over 4 consecutive years from 2009 to 2012 were selected and followed up until gastrointestinal cancer diagnosis, death, or December 31, 2019. The IFG exposure score (range, 0-4) was based on the number of IFG diagnoses over 4years. The median follow-up duration was 6.4years. Consistent normoglycemia for 4years was found in 44.3% of the population, whereas 5.0% had persistent IFG and 50.7% had intermittent IFG. Compared to the group with an IFG exposure score of 0, groups with IFG exposure scores of 1, 2, 3, and 4 had a 5%, 8%, 9%, and 12% increased risk of gastrointestinal cancer, respectively (score 1: adjusted hazard ratio [aHR], 1.05; 95% confidence interval [CI], 1.01-1.08; score 2: aHR, 1.08; 95% CI, 1.04-1.12; score 3: aHR, 1.09; 95% CI, 1.05-1.14; score 4: aHR, 1.12; 95% CI, 1.06-1.19). Persistent IFG exposure was also associated with higher risks of individual cancer types (colorectum, stomach, pancreas, biliary tract, and esophagus). Cumulative exposure to IFG is associated with an increased risk of developing gastrointestinal cancer, in a dose-dependent manner. Hyperglycemia, including both diabetes and prediabetes, has been associated with an increased risk of various cancers. However, the cumulative effect of impaired fasting glucose on the risk of developing gastrointestinal cancer remains unclear. A frequent diagnosis of impaired fasting glucose was dose-dependently associated with a higher risk of developing overall gastrointestinal cancer. Furthermore, risks of individual cancer types increased with persistent impaired fasting glucose. Early detection of hyperglycemia and strict glycemic control can lower the risk of gastrointestinal cancer by reducing hyperglycemic burden. Additionally, for some individuals, lifestyle changes such as managing metabolic syndrome or abstaining from alcohol may also be helpful.

Impact of Rheumatoid Arthritis and Seropositivity on the Risk of Non-Cystic Fibrosis Bronchiectasis

BackgroundDespite the coexistence of bronchiectasis and rheumatoid arthritis (RA) and the poor prognosis associated with the combination of conditions, no longitudinal studies that comprehensively evaluated whether patients with RA have a higher risk of bronchiectasis compared with those without bronchiectasis have been published. Whether seropositivity is associated with an increased risk of bronchiectasis in RA is the subject of ongoing controversy. Research QuestionDoes RA influence the development of bronchiectasis? Is seropositivity associated with an increased risk of bronchiectasis in RA? Study Design and MethodsThe incidence of bronchiectasis was compared between individuals with RA (n=50,651; 35,879 seropositive RA [SPRA] and 14,772 seronegative RA [SNRA]) and 1:5 age- and sex-matched controls (n=253,255) enrolled between 2010 and 2017 in the Korean National Health Insurance Service database. The participants were followed from 1 year after RA diagnosis or the corresponding index date to the date of bronchiectasis incidence, censored date, or December 2019. ResultsThe cumulative incidence of bronchiectasis at 9 years of follow-up was approximately 7% in participants with RA. During a median follow-up of 4.3 years (interquartile range, 2.6–6.3 years), participants with RA showed a 2.12-fold higher risk of developing bronchiectasis compared with matched controls even after adjusting for potential confounders related to bronchiectasis development (95% confidence interval [CI], 2.00–2.25), In an analysis of RA serologic status using a fully adjusted model, participants with SPRA and those with SNRA showed 2.34-fold (95% CI, 2.20–2.49) and 1.56-fold (95% CI, 1.40–1.73) increased risks, respectively, compared with matched controls. InterpretationIndividuals with RA had approximately twice the risk of developing bronchiectasis than matched controls even after adjusting for potential confounders. The increased risk was more evident in individuals with SPRA than in those with SNRA, implying that rheumatic inflammation plays a major role in the development of RA-bronchiectasis.

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

BackgroundMany 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.ObjectivesWe aimed to identify an appropriate algorithm for identifying stroke by applying machine learning (ML) techniques to analyze the claims data.MethodsWe 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.ResultsIn 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%).ConclusionsWe 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.

Risk of Depression according to Cumulative Exposure to a Low-Household Income Status in Individuals with Type 2 Diabetes Mellitus: A Nationwide Population- Based Study.

We aimed to identify the risk of incident depression according to cumulative exposure to a low-household income status in individuals with type 2 diabetes mellitus (T2DM). For this retrospective longitudinal population-based cohort study, we used Korean National Health Insurance Service data from 2002 to 2018. Risk of depression was assessed according to cumulative exposure to low-household income status (defined as Medical Aid registration) during the previous 5 years among adults (aged ≥20 years) with T2DM and without baseline depression who underwent health examinations from 2009 to 2012 (n=2,027,317). During an average 6.23 years of follow-up, 401,175 incident depression cases occurred. Advance in cumulative number of years registered for medical aid during the previous 5 years from baseline was associated with an increased risk of depression in a dose-dependent manner (hazard ratio [HR], 1.44 [95% confidence interval (CI), 1.38 to 1.50]; HR, 1.40 [95% CI, 1.35 to 1.46]; HR, 1.42, [95% CI, 1.37 to 1.48]; HR, 1.46, [95% CI, 1.40 to 1.53]; HR, 1.69, [95% CI, 1.63 to 1.74] in groups with 1 to 5 exposed years, respectively). Insulin users exposed for 5 years to a low-household income state had the highest risk of depression among groups categorized by insulin use and duration of low-household income status. Cumulative duration of low-household income status, defined as medical aid registration, was associated with an increased risk of depression in a dose-response manner in individuals with T2DM.

Fasting glucose variability and risk of dementia in Parkinson's disease: a 9-year longitudinal follow-up study of a nationwide cohort.

Diabetes is associated with an increased risk of Parkinson's disease dementia (PDD); however, it is unknown whether this association is dependent on continuous hyperglycemia, hypoglycemic events, or glycemic variability. We aimed to investigate the relationship between visit-to-visit fasting glucose variability and PDD development in patients with Parkinson's disease (PD). Using data from the Korean National Health Insurance Service, we examined 9,264 patients aged ≥40 years with de novo Parkinson's disease (PD) who underwent ≥3 health examinations and were followed up until December 2019. Glucose variability was measured using the coefficient of variation, variability independent of the mean, and average real variability. Fine and Gray competing regression analysis was performed to determine the effect of glucose variability on incident PDD. During the 9.5-year follow-up period, 1,757 of 9,264 (19.0%) patients developed PDD. Patients with a higher visit-to-visit glucose variability had a higher risk of future PDD. In the multivariable adjusted model, patients with PD in the highest quartile (subdistribution hazard ratio [SHR] = 1.50, 95% CI 1.19 to 1.88), quartile 3 (SHR = 1.29, 95% CI 1.02 to 1.62), and quartile 2 (SHR = 1.30, 95% CI 1.04 to 1.63) were independently associated with a higher risk of PDD than those in the lowest quartile. We highlighted the effect of long-term glucose variability on the development of PDD in patients with PD. Furthermore, our findings suggest that preventive measures for constant glucose control may be necessary to prevent PDD.

Psychotic Disorders and the Risk of Type 2 Diabetes Mellitus, Atherosclerotic Cardiovascular Diseases, and All-Cause Mortality: A Population-Based Matched Cohort Study.

The effects of psychotic disorders on cardiometabolic diseases and premature death need to be determined in Asian populations. In this population-based matched cohort study, the Korean National Health Insurance Service database (2002 to 2018) was used. The risk of type 2 diabetes mellitus (T2DM), acute myocardial infarction (AMI), ischemic stroke, composite of all cardiometabolic diseases, and all-cause death during follow-up was compared between individuals with psychotic disorders treated with antipsychotics (n=48,162) and 1:1 matched controls without psychiatric disorders among adults without cardiometabolic diseases before or within 3 months after baseline. In this cohort, 53,683 composite cases of all cardiometabolic diseases (during median 7.38 years), 899 AMI, and 1,216 ischemic stroke cases (during median 14.14 years), 7,686 T2DM cases (during median 13.26 years), and 7,092 deaths (during median 14.23 years) occurred. The risk of all outcomes was higher in subjects with psychotic disorders than matched controls (adjusted hazard ratios [95% confidence intervals]: 1.522 [1.446 to 1.602] for T2DM; 1.455 [1.251 to 1.693] for AMI; 1.568 [1.373 to 1.790] for ischemic stroke; 1.595 [1.565 to 1.626] for composite of all cardiometabolic diseases; and 2.747 [2.599 to 2.904] for all-cause mortality) during follow-up. Similar patterns of associations were maintained in subgroup analyses but more prominent in younger individuals (P for interaction <0.0001) when categorized as those aged 18-39, 40-64, or ≥65 years. Patients with psychotic disorders treated with antipsychotics were associated with increased risk of premature allcause mortality and cardiometabolic outcomes in an Asian population. This relationship was more pronounced in younger individuals, especially aged 18 to 39 years.

Risk of Parkinson disease in stroke patients: A nationwide cohort study in South Korea.

Previous studies have examined the risk of stroke in patients with Parkinson disease (PD), but the incidence of PD onset among stroke patients and its risk according to severity of poststroke disabilities have scarcely been investigated. This study aims to determine whether the risk of PD is increased among stroke patients using a retrospective cohort with a large population-based database. We used data collected by the Korean National Health Insurance Service from 2010 to 2018 and examined 307,361 stroke patients and 380,917 sex- and age-matched individuals without stroke to uncover the incidence of PD. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI), and the risk of PD was compared according to presence and severity of disability. During 4.31 years of follow-up, stroke patients had a 1.67 times higher risk of PD compared to individuals without stroke (adjusted HR = 1.67, 95% CI = 1.57-1.78). The risk of PD was greater among stroke patients with disabilities than among those without disabilities, even after adjustment for multiple covariates (adjusted HR = 1.72, 95% CI = 1.55-1.91; and adjusted HR = 1.66, 95% CI = 1.56-1.77, respectively). Our study demonstrated an increased risk of PD among stroke patients. Health professionals need to pay careful attention to detecting movement disorders as clues for diagnosing PD.

Socioeconomic Status and Dementia Risk Among Intensive Care Unit Survivors: Using National Health Insurance Cohort in Korea.

In aging populations, more elderly patients are going to the intensive care unit (ICU) and surviving. However, the specific factors influencing the occurrence of post-intensive care syndrome in the elderly remain uncertain. To investigate the association between socioeconomic status (SES) and risk of developing dementia within two years following critical care. This study included participants from the Korean National Health Insurance Service Cohort Database who had not been diagnosed with dementia and had been hospitalized in the ICU from 2003 to 2019. Dementia was determined using specific diagnostic codes (G30, G31) and prescription of certain medications (rivastigmine, galantamine, memantine, or donepezil). SES was categorized into low (medical aid beneficiaries) and non-low (National Health Insurance) groups. Through a 1:3 propensity score matching based on sex, age, Charlson comorbidity index, and primary diagnosis, the study included 16,780 patients. We used Cox proportional hazard models to estimate adjusted hazard ratios (HR) of dementia. Patients with low SES were higher risk of developing dementia within 2 years after receiving critical care than those who were in non-low SES (HR: 1.23, 95% CI: 1.04-1.46). Specifically, patients with low SES and those in the high-income group exhibited the highest incidence rates of developing dementia within two years after receiving critical care, with rates of 3.61 (95% CI: 3.13-4.17) for low SES and 2.58 (95% CI: 2.20-3.03) for high income, respectively. After discharge from critical care, compared to the non-low SES group, the low SES group was associated with an increased risk of developing dementia.

Trend in the Incidence of Severe Partial Edentulism among Adults Using the Korean National Health Insurance Service Claim Data, 2014-2018.

Missing teeth is one of the most important indicators of oral health behavior and the result of dental caries, periodontal disease, and injuries. This study examined a trend in the incidence of severe partial edentulism (SPE) using the Korean National Health Insurance Service (KNHIS) data. Data of adults aged ≥20 years were obtained from the KNHIS for the 2014-2018 period. SPE was defined in dental information within a population with a treatment history of dental scaling as having 1 to 8 natural teeth. Crude incidence rates (CIRs) and age-standardized incidence rates (AIRs) with 95% confidence interval were calculated per 100000 persons. The Cochran Armitage trend (CAT) test and average annual percentage change were used to analyze SPE trends. The CIRs among Korean adults were from 346.29 to 391.11 in 2014-2016 and from 391.11 to 354.09 in 2016-2018. The AIRs trend statistically increased by 4.31% from 346.29 to 376.80 and decreased by 4.72% from 376.80 to 342.10. The AIRs in men increased by 4.00% and decreased by 3.01%. The AIRs in women decreased by 2.18% and increased by 2.11% (CAT; p<0.01). The AIRs by region and income also showed trends of increase and decrease. The study showed that the incidence trend of SPE increased and decreased from 2014 to 2018. This result would be able to aid in the planning of public oral health, and may also serve as fundamental data for verifying the impact of the public oral health policies implemented.

Trends in Triptan Usage in Korea: A Population-Based Cohort Study.

Migraine presents a significant global health problem that emphasizes the need for efficient acute treatment options. Triptans, introduced in the early 1990s, have substantially advanced migraine management owing to their effectiveness compared to that of traditional medications. However, data on triptan use in migraine management from Asian countries, where migraines tend to have milder symptoms than those in European and North American countries, are limited. This study aimed to identify the trends in triptan usage in Korea. This retrospective cohort study used data from the Korean National Health Insurance Service-National Sample Cohort spanning from 2002 to 2019. Patients with migraine were identified using the International Classification of Diseases 10th revision codes, and triptan prescriptions were evaluated annually in terms of quantity, pills per patient, and associated costs. The distribution of triptan prescriptions across different medical specialties was also examined. Factors contributing to the odds of triptan use were analyzed using multivariable logistic regression. From 2002 to 2019, the total number of triptan tablets, prescriptions, and patients using triptans increased by 24.0, 17.1, and 13.6 times, respectively, with sumatriptan being the most frequently prescribed type of triptan. Additionally, the number of prescriptions and related costs have consistently increased despite stable pricing because of government regulation. By 2019, only approximately one-tenth of all patients with migraines had been prescribed triptans, although there was a notable increase in prescriptions over the study period. These prescription patterns varied according to the physician's specialty. After adjusting for patient-specific factors including age and sex, the odds of prescribing triptans were higher for neurologists than for internal medicine physicians (odds ratio 2.875, P < 0.001), while they were lower for general practitioners (odds ratio 0.220, P < 0.001). The findings revealed an increasing trend in triptan use among individuals with migraines in Korea, aligning with global usage patterns. Despite these increases, the overall prescription rate of triptans remains low, indicating potential underutilization and highlighting the need for improved migraine management strategies across all medical fields. Further efforts are necessary to optimize the use of triptans in treating migraines effectively.

Associations Between COVID-19, Delirium, and 1-Year Mortality: Exploring Influences on Delirium Incidence in COVID-19 Patients.

This study investigated the relationship between coronavirus disease 2019 (COVID-19), delirium, and 1-year mortality. Factors associated with delirium in COVID-19 patients were identified, along with the influence of psychotropic medications on delirium. The study used the South Korean National Health Insurance Service database. Adult COVID-19 patients diagnosed between October 2020 and December 2021 were included, with a propensity score-matched control group. Time-dependent Cox regression assessed associations among COVID-19, delirium, and mortality. Logistic regression analyzed the impact of psychotropic medications on delirium incidence. The study included 832,602 individuals, with 416,301 COVID-19 patients. COVID-19 (hazard ratio [HR], 3.03; 95% confidence interval [CI], 2.92-3.13) and delirium (HR, 2.33; 95% CI, 2.06-2.63) were independent risk factors for 1-year mortality. Comorbidities, insurance type, and residence were also related to mortality. Among COVID-19 patients, antipsychotic use was associated with lower delirium incidence (odds ratio [OR], 0.38; 95% CI, 0.30-0.47), while mood stabilizers (OR, 1.77; 95% CI, 1.40-2.21) and benzodiazepines (OR, 8.62; 95% CI, 7.46-9.97) were linked to higher delirium incidence. COVID-19 and delirium are risk factors for 1-year mortality. Some factors associated with delirium in COVID-19 patients are modifiable and can be targeted in preventive and therapeutic interventions.

Time interval between surgery and adjuvant chemotherapy in patients with gastric cancer after gastrectomy: a population-based cohort study using a nationwide claim database.

Adjuvant chemotherapy can reduce recurrence rates by eradicating microscopic metastases which may persist after curative resection. However, the optimal time interval (TI) between the surgery and chemotherapy remains controversial. This study investigated the optimal TI between surgery and chemotherapy. A population-based cohort study using a nationwide claims database. The data were obtained from the Korean National Health Insurance Service (NHIS) of Korea. We included patients who underwent gastrectomy between 2013 and 2018. To determine the optimal cutoff point of TI, a restricted cubic spline Cox regression model was established, and categorized the population into three groups based on TI: the early (⩽20 days), the late (⩾35 days), and the reference group (21-34 days), and with the reference group having the lowest mortality and recurrence. Propensity score matching was performed for each group. The primary outcomes were disease-free survival (DFS) and overall survival (OS). After excluding ineligible participants, 6602 patients were included. The median DFS and OS did not differ significantly between the early and reference groups (p = 0.7258 and p = 0.6056, respectively). In comparison between the late and reference groups, it was significantly lower in the late group (p = 0.0079). Five-year DFS rates were 77.6% and 81.3% in the late and reference groups, respectively. The late group showed worse OS than the reference group (p = 0.0336). Five-year OS rates were 82.1% and 85.0% in the late and reference groups, respectively. In the multivariable analysis, DFS in the late group retained inferiority [adjusted hazard ratio (aHR): 1.138, 95% confidence interval (CI): 1.003-1.292, p = 0.045]. OS showed a worse trend without significance compared to the reference group (aHR: 1.138, 95% CI: 0.984-1.317, p = 0.0805). Adjuvant chemotherapy after gastrectomy in patients with gastric cancer should be initiated within 5 weeks of surgery. A delay of more than 5 weeks may have a detrimental effect on the subsequent disease course.

Increased Risk of Incident Chronic Obstructive Pulmonary Disease and Related Hospitalizations in Tuberculosis Survivors: A Population-Based Matched Cohort Study.

Tuberculosis (TB) survivors have an increased risk of developing chronic obstructive pulmonary disease (COPD). This study assessed the risk of COPD development and COPD-related hospitalization in TB survivors compared to controls. We conducted a population-based cohort study of TB survivors and 1:1 age- and sex-matched controls using data from the Korean National Health Insurance Service database collected from 2010 to 2017. We compared the risk of COPD development and COPD-related hospitalization between TB survivors and controls. Of the subjects, 9.6% developed COPD, and 2.8% experienced COPD-related hospitalization. TB survivors had significantly higher COPD incidence rates (36.7/1,000 vs. 18.8/1,000 person-years, P < 0.001) and COPD-related hospitalization (10.7/1,000 vs. 4.3/1,000 person-years, P < 0.001) than controls. Multivariable Cox regression analyses revealed higher risks of COPD development (adjusted hazard ratio [aHR], 1.63; 95% confidence interval [CI], 1.54-1.73) and COPD-related hospitalization (aHR, 2.03; 95% CI, 1.81-2.27) in TB survivors. Among those who developed COPD, the hospitalization rate was higher in individuals with post-TB COPD compared to those with non-TB COPD (10.7/1,000 vs. 4.9/1,000 person-years, P < 0.001), showing an increased risk of COPD-related hospitalization (aHR, 1.84; 95% CI, 1.17-2.92). TB survivors had higher risks of incident COPD and COPD-related hospitalization compared to controls. These results suggest that previous TB is an important COPD etiology associated with COPD-related hospitalization.

Lower Atrial Fibrillation Risk With Sodium-Glucose Cotransporter 2 Inhibitors Than With Dipeptidyl Peptidase-4 Inhibitors in Individuals With Type 2 Diabetes: A Nationwide Cohort Study.

Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55-0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI, 0.52-0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44-2.44; p=0.936). In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

Comparison of Statin With Ezetimibe Combination Therapy Versus Statin Monotherapy for Primary Prevention in Middle-Aged Adults.

Lipid lowering therapy is essential to reduce the risk of major cardiovascular events; however, limited evidence exists regarding the use of statin with ezetimibe as primary prevention strategy for middle-aged adults. We aimed to investigate the impact of single pill combination therapy on clinical outcomes in relatively healthy middle-aged patients when compared with statin monotherapy. Using the Korean National Health Insurance Service database, a propensity score match analysis was performed for baseline characteristics of 92,156 patients categorized into combination therapy (n=46,078) and statin monotherapy (n=46,078) groups. Primary outcome was composite outcomes, including death, coronary artery disease, and ischemic stroke. And secondary outcome was all-cause death. The mean follow-up duration was 2.9±0.3 years. The 3-year composite outcomes of all-cause death, coronary artery disease, and ischemic stroke demonstrated no significant difference between the 2 groups (10.3% vs. 10.1%; hazard ratio [HR], 1.022; 95% confidence interval [CI], 0.980-1.064; p=0.309). Meanwhile, the 3-year all-cause death rate was lower in the combination therapy group than in the statin monotherapy group (0.2% vs. 0.4%; p<0.001), with a significant HR of 0.595 (95% CI, 0.460-0.769; p<0.001). Single pill combination therapy exhibited consistently lower mortality rates across various subgroups. Compared to the statin monotherapy, the combination therapy for primary prevention showed no difference in composite outcomes but may reduce mortality risk in relatively healthy middle-aged patients. However, since the study was observational, further randomized clinical trials are needed to confirm these findings.

Effect of Cost-Exemption Policy on Treatment Interruption in Patients With Newly Diagnosed Pulmonary Tuberculosis in South Korea.

In 2021, South Korea had the highest incidence rate (49 per 100 000 population) and the third highest mortality rate (3.8 per 100 000 population) due to pulmonary tuberculosis (TB) among Organization for Economic Co-operation and Development countries. Notably, premature interruption of TB treatment interferes with TB control efforts. Therefore, we examined the effect of the co-payment waiver on treatment interruption and mortality among patients with pulmonary TB in South Korea. Patients who had newly treated TB in South Korea from 2013 to 2019 were selected from the nationwide data of the entire Korean National Health Insurance Service (NHIS) population. The effects of policy implementation on treatment adherence and mortality rates depending on treatment interruption history were evaluated. In total, 73 116 and 1673 patients with drug-susceptible (DS) and multidrug-resistant (MDR) pulmonary TB, respectively, were included in the final study population. After implementing the cost-exemption policy, the treatment interruption rate tended to decrease in the continuation phase in the DS-TB group (slope change: -0.097, P=.011). However, it increased in the intensive phase in the MDR-TB group (slope change: 0.733, P=.001). MDR-TB patients were likely to experience an interruption of TB treatment (adjusted odds ratio [aOR], 6.04; 95% CI, 5.43-6.71), and treatment interruption history was a significant risk factor for 1-year and overall mortality rates (adjusted hazard ratios [aHRs]: 2.01, 95% CI, 1.86-2.18 and 1.77, 95% CI, 1.70-1.84, respectively) in the DS-TB group. Implementing the cost-exemption policy effectively reduced the treatment interruption rate among patients with DS pulmonary TB.

Association between nurse staffing level in intensive care settings and hospital-acquired pneumonia among surgery patients: result from the Korea National Health Insurance cohort.

This study examined the association between the number of nursing staff in intensive care units (ICUs) and hospital-acquired pneumonia (HAP) among surgical patients in South Korea. Data were obtained between 2008 and 2019 from the Korean National Health Insurance Service Cohort Database; 37,706 surgical patients who received critical care services were included in the analysis. Patients with a history of pneumonia 1 year prior to surgery or those who had undergone lung-related surgery were excluded. The ICU nursing management fee is an admission fee that varies based on the grading determined by nurse-to-bed ratio. Using this grading system, we classified four groups from the highest to the lowest level based on the proportion of beds to nurses (high, high-mid, mid-low, and low group). HAP was defined by the International Classification of Disease, 10th revision (ICD-10) code. Multilevel logistic regression was used to investigate the relationship between the level of ICU nurse staffing and pneumonia, controlling for variables at the individual and hospital levels. Lower levels of nurse staffing were associated with a greater incidence of HAP than higher levels of nurse staffing (mid-high, OR: 1.33, 95% CI: 1.12-1.57; mid-low, OR: 1.61, 95% CI: 1.27-2.04; low, OR: 2.13, 95% CI: 1.67-2.71). The intraclass correlation coefficient value was 0.177, and 17.7% of the variability in HAP was accounted for by the hospital. Higher ICU nursing management fee grades (grade 5 and above) in general and hospital settings were significantly associated with an increased risk of HAP compared to grade 1 admissions. Similarly, in tertiary hospitals, grade 2 and higher ICU nursing management fees were significantly associated with an increased risk of HAP compared to grade 1 admissions. Especially, a lower level of nurse staffing was associated with bacterial pneumonia but not pneumonia due to aspiration. In conclusion, this study found an association between the level of ICU nurse staffing and HAP among surgical patients. A lower level of nurse staffing in the ICU was associated with increased rates of HAP among surgical patients. This indicates that having fewer beds assigned to nurses in the ICU setting is a significant factor in preventing HAP, regardless of the size of the hospital.

Differences in the risk of clinical failure between thiopurine and methotrexate in bio-naïve patients with Crohn's disease: a Korean nationwide population-based study.

Although immunomodulators are widely prescribed in patients with Crohn's disease (CD), it is unclear whether there is a difference in treatment outcomes between thiopurines and methotrexate (MTX). To compare the risk of clinical failure between thiopurines and MTX in bio-naïve patients with CD. Nationwide, population-based study. We used claims data from the Korean National Health Insurance Service. After inverse probability of treatment weighting, logistic regression and Cox proportional hazard analyses were used to evaluate the risk of clinical failure in bio-naïve patients with CD treated with thiopurine (thiopurine group) or MTX (MTX group). Overall, 10,296 adult and pediatric patients with CD [9912 (96.3%) and 384 (3.7%) in the thiopurine and MTX groups, respectively] were included. The odds ratios (ORs) of failure to induce remission were significantly higher in the MTX group than in the thiopurine group [adjusted OR (aOR), 1.115; 95% confidence interval (CI), 1.045-1.190; p = 0.001]. However, the opposite result was observed only in patients without concomitant steroid use: the MTX group had a lower risk of induction failure than the thiopurine group (aOR, 0.740; 95% CI, 0.673-0.813; p < 0.001). The risk of overall maintenance failure was higher in the MTX group than in the thiopurine group [adjusted hazard ratio (aHR), 1.117; 95% CI, 1.047-1.191; p = 0.001]. The risk of overall maintenance failure was higher in the standard-dose MTX group than in the low-dose MTX group (aHR, 1.296; 95% CI, 1.134-1.480; p < 0.001). There was no significant difference in the risk of maintenance failure according to the administration route of MTX. Thiopurine is more effective than MTX in inducing and maintaining remission in bio-naïve patients with CD; however, the concomitant use of steroids influences inducing remission.