Understanding and Utilizing Claim Data from the Korean National Health Insurance Service (NHIS) and Health Insurance Review & Assessment (HIRA) Database for Research

Impact of perioperative COVID-19 infection on postoperative complication in cesarean section using Korean National Health insurance data

The vulnerability during pregnancy has raised concerns about the potential impact of COVID-19 on obstetric anesthesia, an essential aspect of maternal care during cesarean section procedures. To evaluate the influence of COVID-19 infection on obstetric anesthesia during cesarean section, we analyzed the data from Korean National Health Insurance System (NHIS). This retrospective study utilized data from Korean NHIS. We included patients admitted with operation codes specific to cesarean section between January 1, 2020, and December 31, 2021. We classified patients into a COVID (+) group with a diagnosis code (U071) 30 days around surgery and a COVID (-) group without the code in the same period. The primary outcome was 30-day mortality that was defined as death within 30 days of admission due to any causes. Secondary outcomes were pulmonary complications (pneumonia, acute respiratory distress syndrome [ARDS], pulmonary thromboembolism [PTE], or unexpected postoperative mechanical ventilation), ICU admission, cardiac arrest, myocardial infarction [MI], other thromboembolic events, surgical site infection, sepsis, acute renal failure [ARF], and hepatic failure. Among 75,268 patients who underwent cesarean section, 107 had a COVID-19 diagnosis code, while 75,161 did not. After 1:4 propensity score matching (PSM), 535 patients were included in each group. 30-day mortality showed no significant differences between the two groups both before and after PSM. The COVID (+) group demonstrated significantly elevated rates of pneumonia, ARDS, PTE, and surgical site infection both before and after PSM. Hospital length of stay and admission costs were also significantly longer and higher, respectively, in the COVID (+) group before and after PSM. In subgroup analysis, no differences were observed in mortality and postoperative complications based on the anesthesia method after matching. COVID-19 infection is associated with increased rates of postoperative complications, including pneumonia, ARDS, PTE, surgical site infection, longer hospital stays, and increased admission costs, in patients who underwent cesarean section.

One-year post-acute COVID-19 syndrome and mortality in South Korea: a nationwide matched cohort study using claims data

Background

Current understanding of post-COVID-19 syndrome in South Korea is primarily based on survey studies or research targeting specific patient groups, such as those hospitalized. Moreover, the majority of relevant studies have been conducted in European and North American populations, which may limit their applicability to the South Korean context. To address this gap, our study explores the one-year outcomes of COVID-19, focusing on the potential post-acute syndrome and all-cause mortality in South Korea.

Methods

This retrospective cohort study used nationwide claims data in South Korea, including adults aged >18 with records between January 20, 2020, and February 25, 2021. Patients were classified into COVID-19 and non-COVID-19 groups and matched 1:1 based on propensity scores. Primary outcomes were 12-month post-acute COVID-19 syndrome and all-cause mortality.

Results

The study involved 34,802 matched patients. The COVID-19 group had significantly elevated risks of coagulopathies (OR = 2.70 [2.24, 3.28]; p < 0.001), chronic lower respiratory diseases (OR = 1.96 [1.80, 2.14]; p < 0.001), symptoms of the circulatory and respiratory systems (OR = 1.91 [1.80, 2.04]; p < 0.001), mood disorders (OR = 1.67 [1.51, 1.86]; p < 0.001), cardiac diseases (OR = 1.39 [1.21, 1.59]; p < 0.001), and symptoms of cognition, perception, emotional state, and behavior (OR = 1.15 [1.04, 1.27]; p = 0.005). All-cause mortality was higher in the COVID-19 group during the 6 months (OR = 1.34 [1.06, 1.69]; p = 0.015), but gradually decreased, reaching an OR of 0.996 ([0.83, 1.19]; p = 0.964) at 1 year.

Conclusion

In South Korea, the 12-month post-acute COVID-19 syndrome includes coagulopathies, respiratory issues, mood disorders, and cardiac diseases. The risk of all-cause mortality post-COVID-19 is heightened for up to 6 months, then significantly decreases and resolves within a year.

Impact of linkage level on inferences from big data analyses in health and medical research: an empirical study

BACKGROUND

Linkage errors that occur according to linkage levels can adversely affect the accuracy and reliability of analysis results. This study aimed to identify the differences in results according to personally identifiable information linkage level, sample size, and analysis methods through empirical analysis.

METHODS

The difference between the results of linkage in directly identifiable information (DII) and indirectly identifiable information (III) linkage levels was set as III linkage based on name, date of birth, and sex and DII linkage based on resident registration number. The datasets linked at each level were named as databaseIII (DBIII) and databaseDII (DBDII), respectively. Considering the analysis results of the DII-linked dataset as the gold standard, descriptive statistics, group comparison, incidence estimation, treatment effect, and moderation effect analysis results were assessed.

RESULTS

The linkage rates for DBDII and DBIII were 71.1% and 99.7%, respectively. Regarding descriptive statistics and group comparison analysis, the difference in effect in most cases was "none" to "very little." With respect to cervical cancer that had a relatively small sample size, analysis of DBIII resulted in an underestimation of the incidence in the control group and an overestimation of the incidence in the treatment group (hazard ratio [HR] = 2.62 [95% confidence interval (CI): 1.63-4.23] in DBIII vs. 1.80 [95% CI: 1.18-2.73] in DBDII). Regarding prostate cancer, there was a conflicting tendency with the treatment effect being over or underestimated according to the surveillance, epidemiology, and end results summary staging (HR = 2.27 [95% CI: 1.91-2.70] in DBIII vs. 1.92 [95% CI: 1.70-2.17] in DBDII for the localized stage; HR = 1.80 [95% CI: 1.37-2.36] in DBIII vs. 2.05 [95% CI: 1.67-2.52] in DBDII for the regional stage).

CONCLUSIONS

To prevent distortion of the analyses results in health and medical research, it is important to check that the patient population and sample size by each factor of interest (FOI) are sufficient when different data are linked using DBDII. In cases involving a rare disease or with a small sample size for FOI, there is a high likelihood that a DII linkage is unavoidable.

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

Importance

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.

Objective

To evaluate the impact of celebrity mental health disclosures on the incidence and prevalence of panic disorder diagnosis in South Korea.

Design, Setting, and Participants

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.

Exposure

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).

Main Outcomes and Measures

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.

Results

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.

Conclusions and Relevance

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.

A nationwide study of breast reconstruction after mastectomy in patients with breast cancer receiving postmastectomy radiotherapy: comparison of complications according to radiotherapy fractionation and reconstruction procedures

BACKGROUND

We examined the patterns of breast reconstruction postmastectomy in breast cancer patients undergoing postmastectomy radiotherapy (PMRT) and compared complications based on radiotherapy fractionation and reconstruction procedures.

METHODS

Using National Health Insurance Service (NHIS) data (2015-2020), we analysed 4669 breast cancer patients with PMRT and reconstruction. Using propensity matching, cohorts for hypofractionated fractionation (HF) and conventional fractionation (CF) were created, adjusting for relevant factors and identifying grade ≥3 complications.

RESULT

Of 4,669 patients, 30.6% underwent HF and 69.4% CF. The use of HF has increased from 19.4% in 2015 to 41.0% in 2020. Immediate autologous (32.9%) and delayed two-stage implant reconstruction (33.9%) were common. Complication rates for immediate (N = 1286) and delayed two-stage (N = 784) reconstruction were similar between HF and CF groups (5.1% vs. 5.4%, P = 0.803, and 10.5% vs. 10.7%, P = 0.856, respectively) with median follow-ups of 2.5 and 2.6 years. HF showed no increased risk of complications across reconstruction methods.

CONCLUSION

A nationwide cohort study revealed no significant difference in complication rates between the HF and CF groups, indicating HF for reconstructed breasts is comparable to CF. However, consultation regarding the fractionation for reconstructed breast cancer patients may still be necessary.

Real-world evidence of brigatinib as second-line treatment after crizotinib for ALK+ non-small cell lung cancer using South Korean claims data (K-AREAL)

PURPOSE

There is a lack of real-world data in Asian populations for brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor for patients with non-small cell lung cancer (NSCLC). This study analysed real-world outcomes and dosing patterns for brigatinib in patients with crizotinib-refractory ALK+ NSCLC in South Korea.

METHODS

This retrospective, non-interventional, cohort study used South Korean Health Insurance and Review Assessment claims data for adults with ALK+ NSCLC who initiated brigatinib between 19 April 2019 and 31 March 2021 after receiving prior crizotinib. Patients' characteristics, time to discontinuation (TTD), time to dose reduction, overall survival (OS) and treatment adherence were assessed.

RESULTS

The study included 174 patients (56.9% male; 27.0% with a history of brain metastases). Median duration of prior crizotinib was 17 (range 0.3-48) months. Median follow-up after brigatinib initiation was 18 (range 0-34) months. Overall, 88.5% of patients received full-dose brigatinib (180 mg/day) and 93.1% of patients were adherent (proportion of days covered ≥0.8). The median TTD was 24.9 months (95% CI 15.2-not reached). The probability of continuing treatment was 63.2% at 1 year and 51.5% at 2 years. The probability of continuing at full or peak dose was 79.7% at 1 year and 75.6% at 2 years. Median OS was not reached. The 2-year OS rate was 68.7%.

CONCLUSIONS

In this first nationwide retrospective study using national insurance claim data, brigatinib demonstrated real-world clinical benefit as second-line treatment after prior crizotinib in ALK+ NSCLC patients in South Korea.

Increased risk of fragility fractures in patients with primary biliary cholangitis

Large-scale studies on the risk of fragility fractures in patients with primary biliary cholangitis (PBC) are limited due to low incidence. We aimed to investigate whether PBC is associated with fragility fractures using real-world nationwide data. The Korean National Health Insurance Service claims data from 2007 to 2020 were analyzed in this population-based cohort study. Patients with PBC (n = 4951) were matched with controls (n = 19 793) using a 1:4 ratio based on age, sex, and follow-up duration. The primary outcome was fragility fracture, which comprised fractures of the vertebra, hip, distal radius, and proximal humerus. The incidence rates (IRs) and hazard ratios (HRs) were determined to assess the impact of PBC on fragility fractures. During the median follow-up period of 5.37 years, 524 patients in the PBC group had fragility fractures (IR, 18.59/1000 person-years [PYs]). After adjusting for covariates, PBC increased the risk of fragility fractures by 1.63-fold (95% confidence interval, 1.20-2.22; P = .002). The vertebra and hip were particularly susceptible to fracture in patients with PBC, with adjusted HRs of 1.77 and 2.23, respectively. In the subgroup analysis, the risk of fragility fracture was 2.53-fold higher in men and 1.59-fold higher in women with PBC than that in the respective matched control groups. Considering the morbidity and mortality related to fragility fractures, increasing awareness of fragility fracture risk and implementing appropriate preventive measures in patients with PBC are imperative.

Association Between Changes in Smoking Habits and Incident Fracture After Acute Ischemic Stroke

BACKGROUND

Survivors of stroke, particularly the older population, are at an increased risk of falls and incident fractures. Smoking is a widely recognized risk factor for fractures. However, the association between changes in smoking habits before and after an index stroke and increased risk of fracture remains unelucidated.

METHODS AND RESULTS

Using the Korean National Health Insurance program, patients with ischemic stroke between 2010 and 2016 were enrolled. Individuals were classified by smoking habits: "never smoker," "former smoker," "smoking quitter," "new smoker," and "sustained smoker." The primary outcome was the composite outcome of the vertebral, hip, and any fractures. Multivariable Cox proportional hazards regression analysis was conducted, using the never-smoker group as the reference. Among 177 787 patients with health screening data within 2 years before and after ischemic stroke, 14 991 (8.43%) patients had any fractures. After multivariable adjustment, the sustained smokers had a significantly increased risk of composite primary outcomes of any, vertebral, and hip fractures (adjusted HR [aHR], 1.222 [95% CI, 1.124-1.329]; aHR, 1.27 [95% CI, 1.13-1.428]; aHR, 1.502 [95% CI, 1.218-1.853], respectively). Additionally, the new smoker group exhibited a similar or higher risk of any fractures and hip fractures (aHR, 1.218 [95% CI, 1.062-1.397]; aHR, 1.772 [95% CI, 1.291-2.431], respectively).

CONCLUSIONS

Sustained smokers had a significantly increased risk of vertebral and hip fractures after an ischemic stroke. The risk of any hip fractures was higher in new smokers after ischemic stroke. As poststroke fractures are detrimental to the rehabilitation process of patients with stroke, physicians should actively advise patients to stop smoking.

Prevalence and Incidence of Strabismus by Age Group in Japan: A Nationwide Population-Based Cohort Study

PURPOSE

To investigate the prevalence and incidence of strabismus in the Japanese population by age group and to estimate the subtype proportions.

DESIGN

A nationwide population-based cohort study.

METHODS

This study investigated the number of cases with previous and new diagnoses of strabismus by age group between 2009 and 2020 using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which includes almost all (≥95%) medical claims data. We calculated the strabismus prevalence and 1-year incidence in 2019 and analyzed the proportion of each strabismus subtype.

RESULTS

The strabismus prevalence was 2.154% (2 709 207/125 708 000; 95% CI, 2.152%-2.157%). It showed a bimodal distribution, with a high proportion in school and old ages (especially ≥75 years). Exotropia, esotropia, and cyclovertical strabismus proportions were 67.3%, 26.0%, and 6.7%, respectively. Cyclovertical strabismus was uncommon in patients aged ≤18 years (1.4%) and more common (10.2%) in those aged >18 years. The strabismus incidence in 2019 was 321 per 100 000 person-years (403 093/125 708 000; 95% CI, 320-322). The annual incidence proportion of cyclovertical strabismus as opposed to whole strabismus subtypes in patients aged >18 years (13.1%) was higher than that in those aged ≤18 years (1.4%).

CONCLUSIONS

This is the first nationwide population-based cohort study to demonstrate strabismus's overall prevalence and incidence. The high prevalence of cyclovertical strabismus in adults compared with children may suggest that cyclovertical strabismus is a primarily age-related strabismus. The high prevalence of exotropia may indicate a genetic difference between Japanese and other ethnicities.

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

Background

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).

Objective

To compare the risk of clinical failure between thiopurines and MTX in bio-naïve patients with CD.

Design

Nationwide, population-based study.

Methods

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).

Results

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.

Conclusion

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.

Association between physical activity changes and incident myocardial infarction after ischemic stroke: a nationwide population-based study

BACKGROUND

The impact of changes in physical activity after ischemic stroke (IS) on the subsequent myocardial infarction (MI) risk is not fully understood. We aimed to investigate the effects of changes in physical activity on the risk of MI after acute IS using data from the Korean National Health Insurance Services Database.

METHODS

224,764 patients newly diagnosed with IS between 2010 and 2016 who underwent two serial biannual health checkups were included. The participants were divided into four categories according to changes in their physical activity: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. The primary outcome was a new diagnosis of incident MI. Multivariable Cox proportional models were used to assess the effects of changes in exercise habits on the risk of MI.

RESULTS

After a median of 4.25 years of follow-up, 6,611 (2.94%) MI cases were observed. After adjusting for confounders, new exercisers and exercise maintainers were significantly associated with a lower risk of incident MI than persistent non-exercisers (aHR, 0.849; 95% CI, 0.792-0.911; P-value < 0.001; and aHR, 0.746; 95% CI, 0.696-0.801; P-value < 0.001, respectively). Effects were consistent across sexes, more pronounced in those > 65 years. Notably, any level of physical activity after stroke was associated with a reduced MI risk compared to no exercise.

CONCLUSIONS

In this nationwide cohort study, commencing or sustaining physical activity after an IS corresponded to a diminished likelihood of subsequent MI development. Advocating physical activity in ambulatory stroke survivors could potentially attenuate the prospective risk of MI.

2023 Diabetic Kidney Disease Fact Sheet in Korea

BACKGRUOUND

To investigate the prevalence, incidence, comorbidities, and management status of diabetic kidney disease (DKD) and diabetes-related end-stage kidney disease (ESKD) in South Korea.

METHODS

We used the Korea National Health and Nutrition Examination Survey data (2019 to 2021, n=2,665) for the evaluation of prevalence, comorbidities, control rate of glycemia and comorbidities in DKD, and the Korean Health Insurance Service-customized database (2008 to 2019, n=3,950,857) for the evaluation of trends in the incidence and prevalence rate of diabetes-related ESKD, renin-angiotensin system (RAS) blockers and sodium glucose cotransporter 2 (SGLT2) inhibitors use for DKD, and the risk of atherosclerotic cardiovascular disease (ASCVD) and mortality according to DKD stages. DKD was defined as albuminuria or low estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in patients with diabetes mellitus.

RESULTS

The prevalence of DKD was 25.4% (albuminuria, 22.0%; low eGFR, 6.73%) in patients with diabetes mellitus aged ≥30 years. Patients with DKD had a higher rate of comorbidities, including hypertension, dyslipidemia, and central obesity; however, their control rates were lower than those without DKD. Prescription rate of SGLT2 inhibitors with reduced eGFR increased steadily, reaching 5.94% in 2019. Approximately 70% of DKD patients were treated with RAS blockers. The prevalence rate of diabetesrelated ESKD has been steadily increasing, with a higher rate in older adults. ASCVD and mortality were significantly associated with an in increase in DKD stage.

CONCLUSION

DKD is prevalent among Korean patients with diabetes and is an independent risk factor for cardiovascular morbidity and mortality, which requiring intensive management of diabetes and comorbidities. The prevalence of diabetes-related ESKD has been increasing, especially in the older adults, during past decade.

Outcomes of non-vitamin K oral anticoagulants for secondary prevention in ischemic stroke with atrial fibrillation

Previous studies have rarely investigated the role of non-vitamin K oral anticoagulants (NOAC) and warfarin in the secondary prevention of ischemic stroke patients with nonvalvular atrial fibrillation (NVAF). In this study, we compared the effectiveness and safety of NOAC and warfarin for secondary prevention in Korean ischemic stroke patients with NVAF. Based on the Korean National Health Insurance Service Database, this study included 21,064 oral anticoagulants-naïve acute ischemic stroke patients with NVAF between July 2015 and June 2019. The main study outcomes included ischemic stroke, systemic embolism, major bleeding, and death. During the observational periods, NOAC users had a significantly decreased risk of ischemic stroke + systemic embolism (adjusted hazard ratio [aHR] 0.86; 95% confidence interval [CI] 0.78-0.95), ischemic stroke (aHR 0.89; 95% CI 0.81-0.99), major bleeding (aHR 0.78; 95% CI 0.68-0.89), and all-cause death (aHR 0.87; 95% CI 0.81-0.93). Standard-dose NOAC users had a lower risk of ischemic stroke, systemic embolism, and major bleeding events than warfarin users. In contrast, low-dose NOAC users did not differ in risk from warfarin users for all outcomes. In conclusion, NOACs were associated with a lower risk of secondary thromboembolic events and bleeding complications in Korean ischemic stroke patients with NVAF than warfarin.

Epidemiology of autoimmune liver disease in Korea: evidence from a nationwide real-world database

BACKGROUND

Autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are all immune-mediated chronic inflammatory liver diseases. Autoimmune liver diseases are rare, making identification and treatment difficult. To improve clinical outcomes and enhance patient quality of life, we performed an epidemiological study of autoimmune liver diseases based on real-world comprehensive data.

RESULTS

We used National Health Insurance Service claims data in Korea from 2005 to 2019. Patients were identified using the International Classification of Disease 10th Revision code, and rare intractable disease codes assigned according to the strict diagnostic criteria. In the AIH cohort, 8,572 (83.9%) were females and the mean age at diagnosis was 56.3 ± 14.3 years. PBC also showed female dominance (83.3%) and the mean age was 57.8 ± 12.6 years. Patients with PSC showed no sex predominance and had a mean age of 57.8 ± 21.5 years. During the study period, there were 10,212, 6,784, and 888 AIH, PBC, and PSC patients, respectively. The prevalence of AIH, PBC, and PSC in 2019 were 18.4, 11.8, and 1.5 per 100,000 population, while the corresponding incidences were 2.3, 1.4, and 0.3 per 100,000 population, respectively. Analysis of sex-age-standardized data showed that the annual prevalence of these diseases is increasing. The 10-year survival rates were 89.8%, 74.9%, and 73.4% for AIH, PBC, and PSC, respectively.

CONCLUSIONS

The number of patients with autoimmune liver disease in South Korea is increasing over time. Further research on autoimmune liver disease is needed to fulfill unmet clinical needs.

Blind Spots in Therapy: Unveiling Drug-Induced Angle-Closure Glaucoma Through a National Analysis

OBJECTIVE

To identify and quantify medications causing angle-closure glaucoma through the FDA Adverse Event Reporting System (FAERS).

DESIGN

National retrospective database analysis.

SUBJECTS

There were 11 737 133 total adverse event reports from the FDA Federal Adverse Event Reporting System (FAERS) database 2004 to third quarter of 2023 (2023Q3), which included 1629 reports of angle-closure glaucoma.

METHODS

Drugs associated with reports of angle-closure glaucoma were identified in FAERS through disproportionality analysis MAIN OUTCOME MEASURES: To ascertain if these reports yielded statistically significant signals, we used the proportional reporting ratio (PRR), reporting odds ratio (ROR), empirical Bayes geometric mean (EBGM), and information component (IC). We considered a signal to be detected when all 4 disproportionality analysis metrics were positive.

RESULTS

We identified a total of 1629 adverse event reports linked to 611 suspected drugs over the course of 20 years (2004-2023Q3). Frequently reported drugs included topiramate (520 reports) and citalopram (69 reports), amongst many others. Eighteen medications yielded a positive signal, including lesser-known medications like olanzapine, phentermine, and ranibizumab. Tropicamide exhibited the most robust statistical significance (n = 18; PRR: 164.263; ROR [95% confidence interval {CI}]: 167.95 [104.994-268.655]; EBGM [EBGM05]: 162.421 [109.5]; IC [IC05]: 7.344 [4.591]), while acetazolamide was the second strongest (n = 51; PRR: 113.088; ROR 95% CI: 114.782 [86.665-152.021]; EBGM [EBGM05]: 109.506 [86.501]; IC [IC05]: 6.775 [5.115]).

CONCLUSIONS

Drug-induced glaucoma included both well-known medications such as topiramate as well as lesser-known medications such as olanzapine, phentermine, and ranibizumab. Clinician awareness of these findings is important.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Risk factors of reattempt among suicide attempters in South Korea: A nationwide retrospective cohort study

This study aimed to identify underlying demographic and clinical characteristics among individuals who had previously attempted suicide, utilizing the comprehensive Health Insurance Review and Assessment Service (HIRA) database. Data of patients aged 18 and above who had attempted suicide between January 1 and December 31, 2014, recorded in HIRA, were extracted. The index date was identified when a suicide attempt was made within the year 2014. The medical history of the three years before the index date and seven years of follow-up data after the index date were analyzed. Kaplan-Meier estimate was used to infer reattempt of the suicide attempters, and Cox-proportional hazard analysis was used to investigate risk factors associated with suicide reattempts. A total of 17,026 suicide attempters were identified, of which 1,853 (10.9%) reattempted suicide; 4,925 (28.9%) patients had been diagnosed with depressive disorder. Of the reattempters, 391 (21.1%) demonstrated a history of suicide attempts in the three years before the index date, and the mean number of prior attempts was higher compared to that of the non-reattempters (1.7 vs.1.3, p-value < 0.01). Prior psychiatric medication, polypharmacy, and an increase in the number of psychotropics were associated with suicide reattempt in overall suicide attempters. (Hazard ratio (HR) = 3.20, 95% confidence interval [CI] = 2.56-4.00; HR = 2.42, 95% CI = 1.87-3.14; HR = 19.66, 95% CI = 15.22-25.39 respectively). The risk of reattempt decreased in individuals receiving antidepressant prescriptions compared to those unmedicated, showing a reduction of 78% when prescribed by non-psychiatrists and 89% when prescribed by psychiatrists. Similar risk factors for suicide reattempts were observed in the depressive disorder subgroup, but the median time to reattempt was shorter (556.5 days) for this group compared to that for the overall attempters (578 days). Various risk factors including demographics, clinical characteristics, and medications should be considered to prevent suicide reattempts among suicide attempters, and patients with depressive disorder should be monitored more closely.

Association between underweight and risk of heart failure in diabetes patients

BACKGROUND

The risk of heart failure (HF) in underweight diabetes mellitus (DM) patients has rarely been studied. We conducted a cohort study to investigate the association between underweight (BMI < 18.5 kg/m2) and BMI change over time and the risk of HF in patients with type 2 DM.

METHODS

We utilized the health screening data from the National Health Insurance Service and the Korean National Health Screening database from 2009 to 2012, with follow-up until December 2018. Participants with DM were categorized into four groups based on their BMI at 4 years before study inclusion and BMI at the study entry: (1) Always Normal Weight (BMI at 4 years ago/BMI at study entry ≥18.5/≥18.5 kg/m2, reference group); (2) Transitioned to Underweight (≥18.5/<18.5 kg/m2); (3) Transitioned to Normal Weight (<18.5/≥18.5 kg/m2) and (4) Always Underweight (<18.5/<18.5 kg/m2). Participants were followed until the development of HF or at the end of the follow-up. Initial screening data included participants with DM who had the health screening during the study period (n = 2,746,079). Participants aged <20 years (n = 390), those who did not undergo health examination 4 years prior (n = 1,306,520), and those with missing data (n = 77,410) were excluded. Participants diagnosed with HF before study participation (n = 81,645) and within 1 year of study enrolment (n = 11,731) were excluded. After applying exclusion criteria, 1,268,383 participants were finally included in the analysis. The primary outcome was the development of HF. We employed Cox proportional hazards models, adjusting for various confounding factors, to assess the risk of developing HF.

RESULTS

Median follow-up duration was 6.88 years and men were 63.16%. The mean ages of each groups were as follows: Always Normal Weight (57.92 ± 11.64 years), Transitioned to Underweight (62 ± 13.5 years), Transitioned to Normal Weight (56.6 ± 15.29 years) and Always Underweight (57.76 ± 15.35 years). In comparison with the Always Normal Weight group (n = 1,245,381, HF = 76,360), Transitioned to Underweight group (≥18.5/<18.5 kg/m2, n = 9304, HF = 880, adjusted Hazard Ratio (aHR)1.389, 95% confidence interval (CI) 1.3-1.485) or Transitioned to Normal Weight (<18.5/≥18.5 kg/m2, n = 6024, HF = 478, aHR 1.385, 95% CI 1.266-1.515) exhibited an increased risk of HF. The highest risk was observed in the Always Underweight group (<18.5/<18.5 kg/m2, n = 7674, HF = 665, aHR 1.612, 95% CI 1.493-1.740).

CONCLUSIONS

Underweight was significantly associated with the risk of HF in the DM population. Active surveillance for HF in an underweight DM population is needed.

Health Inequities in Cancer Incidence According to Economic Status and Regions Are Still Existed Even under Universal Health Coverage System in Korea: A Nationwide Population Based Study Using the National Health Insurance Database

PURPOSE

The purpose of this study is to determine the level of health equity in relation to cancer incidence.

MATERIALS AND METHODS

We used the National Health Insurance claims data of the National Health Insurance Service between 2005 and 2022 and annual health insurance and medical aid beneficiaries between 2011 and 2021 to investigate the disparities of cancer incidence. We calculated age-sex standardized cancer incidence rates by cancer and year according to the type of insurance and the trend over time using the annual percentage change. We also compared the hospital type of the first diagnosis by cancer type and year and cancer incidence rates by cancer type and region in 2021 according to the type of insurance.

RESULTS

The total cancer incidence increased from 255,971 in 2011 to 325,772 cases in 2021. The absolute difference of total cancer incidence rate between the NHI beneficiaries and the medical aid (MA) recipients increased from 510.1 cases per 100,000 population to 536.9 cases per 100,000 population. The odds ratio of total cancer incidence for the MA recipients increased from 1.79 (95% confidence interval [CI], 1.77 to 1.82) to 1.90 (95% CI, 1.88 to 1.93). Disparities in access to hospitals and regional cancer incidence were profound.

CONCLUSION

This study examined health inequities in relation to cancer incidence over the last decade. Cancer incidence was higher in the MA recipients, and the gap was widening. We also found that regional differences in cancer incidence still exist and are getting worse. Investigating these disparities between the NHI beneficiaries and the MA recipients is crucial for implementing of public health policies to reduce health inequities.

Association between children with attention-deficit hyperactivity disorder and parental mental health: Data from the 2011-2020 Korea National Health and Nutrition Examination Survey

BACKGROUND

The aim of this study was to investigate whether children's attention-deficit hyperactivity disorder (ADHD) is associated with parental mental health, using data from the Korean National Health and Nutrition Examination Survey (KNHANES).

METHODS

This cross-sectional study included 14,428 samples from KNHANES of parents with children younger than 19 years between 2011 and 2020. Mental health problems, measured as perceived stress, depressive symptoms, and suicidality, were assessed. Sociodemographic and health-related characteristics were collected as potential confounding factors. The association between children with ADHD and parental mental health problems was expressed as odds ratio and 95 % confidence interval with multivariate logistic regression using PROC SURVEYLOGISTIC.

RESULTS

Among the 14,428 participants, 202 (1.4 %) were classified as parents of children with ADHD. Mothers of children with ADHD reported higher perceived stress (aOR = 1.67, 95 % CI 1.09-2.56), depressive symptoms (aOR = 2.93, 95 % CI 1.59-5.40), and suicidality (aOR = 2.63, 95 % CI 1.29-5.38) than those of children without ADHD after adjusting for parents' age, gender, and parental education level, employment status, cohabitation status, drinking, smoking, and number of children. However, fathers' mental health problems were not significantly associated with having a child with ADHD.

LIMITATION

Because it was conducted the analysis using cross-sectional data, findings on causality are unclear.

CONCLUSIONS

The current findings suggest that parenting children with ADHD is associated with parental mental health problems. Parents of children with ADHD, especially mothers, need community support and public health attention to help alleviate their mental health problems.

Comparative Analysis of Seven Equations for Estimated Glomerular Filtration Rate and Their Impact on Chronic Kidney Disease Categorization in Korean Patients at Local Clinics and Hospitals

(1) Background: Accurate estimation of the glomerular filtration rate (eGFR) is essential for the early detection of chronic kidney disease (CKD), targeted interventions, and ongoing monitoring. Although various equations for calculating eGFR exist, comparative studies on eGFR levels and the impact of these equations on CKD prevalence are limited in the Korean population. (2) Methods: We compared eGFR levels calculated using seven equations and investigated the prevalence of CKD through a retrospective analysis of the data from Korean adult patients who visited local clinics and hospitals and underwent simultaneous serum creatinine (Cr) and cystatin C (Cys-C) measurements. The equations analyzed were: 2006 MDRD, 2009 CKD-EPI Cr, 2012 CKD-EPI Cys-C, 2012 CKD-EPI Cr & Cys-C, 2021 CKD-EPI Cr, 2021 CKD-EPI Cr & Cys-C, and 2021 EKFC. (3) Results: This study included 6688 Korean patients (3736 men and 2952 women; median age: 61.4; IQR: 47.2-73.4). Among the equations, the median eGFR levels were the highest when using the 2021 CKD-EPI Cr & Cys-C equation (85.1 mL/min/1.73 m2) and the lowest when using the 2006 MDRD equation (73.4 mL/min/1.73 m2). The highest prevalence of decreased eGFR < 60 mL/min/1.73 m2 (equivalent to or worse than G3a CKD) was noted with the 2012 CKD-EPI Cys-C equation (32.4%), while the lowest was with the 2021 CKD-EPI Cr equation (22.9%), resulting in a maximum prevalence difference of 9.5%. (4) Conclusions: The prevalence of CKD varies based on the eGFR equation used and the patient's age. Equations that include Cys-C may identify a larger number of patients with decreased kidney function.

Incidence rates of retinal vascular occlusive diseases from 2011 to 2020 in South Korea: a nationwide cohort study

BACKGROUND

Retinal vascular occlusions, including retinal vein occlusion and retinal artery occlusion, are common causes of visual impairment. In order to evaluate the national medical burden and help improve ophthalmic health care policy planning, we investigated the incidence of retinal vascular occlusive diseases from 2011 to 2020 in Korea.

METHODS

This study is a nationwide population-based retrospective study using data from the Korea national health claim database of the Health Insurance Review and Assessment (HIRA) service. We identified retinal vascular occlusive diseases registered from January 1, 2009, to December 31, 2020, according to the retinal vascular occlusion code (H34) and its sub-codes from international classification of disease, tenth revision diagnosis code. We used data from the entire Korean population based on the 2015 census of the population in Korea to calculate standardized incidence rates.

RESULTS

We identified 348,775 individuals (male, 161,673 [46.4%]; female, 187,102 [53.6%]) with incident retinal vascular occlusion (H34), 10,451 individuals (males, 6,329 [60.6%]; females, 4,122 [39.4%]) with incident central retinal artery occlusion (H34.1), and 252,810 individuals (males, 114,717 [45.4%]; females, 138,093 [54.6%]) with incident retinal vein occlusion (H34.8) during the 10-year study period. The weighted mean incidence rate of retinal vascular occlusion was 70.41 (95% CI, 70.18-70.65) cases/100,000 person-years. The weighted mean incidence rate of central retinal artery occlusion was 2.10 (95% CI, 2.06-2.14) cases/100,000 person-years. The weighted mean incidence rate of retinal vein occlusion was 50.99 (95% CI, 50.79-51.19) cases/100,000 person-years.

CONCLUSION

The total retinal vascular occlusion and retinal vein occlusion showed a decreasing trend until 2020. However, the central retinal artery occlusion decreased until 2014 and remained stable without a significant further decline until 2020. The incidence of total retinal vascular occlusion and retinal vein occlusion was higher in females than in males, while the incidence of central retinal artery occlusion was higher in males. All retinal vascular occlusive diseases showed an increasing incidence with older age; the peak age incidence was 75-79 years for total retinal vascular occlusion and retinal vein occlusion, and 80-85 years for central retinal artery occlusion.

Healthcare service use and medical outcomes of tracheostomy-dependent children: a nationwide study

BACKGROUND

Despite the rising trend of tracheostomies in children, there is a lack of comprehensive resources for families to navigate the challenges of living with a tracheostomy, emphasising the need for evidence-based support in understanding postoperative care and long-term adjustments. This study aimed to examine the pattern of using healthcare services and nationwide medical outcomes in children who underwent a tracheotomy before the age of 2 years.

METHODS

This retrospective study used the National Health Insurance System database from 2008 to 2016 and included all children codified with tracheotomy procedure codes before their second birthday. Healthcare utilisation, such as medical costs, number of hospital visits, home healthcare nursing and medical diagnoses on readmission, in the first 2 years after tracheotomy was evaluated. Multivariable logistic regression analysis was used to determine the factors affecting mortality.

RESULTS

In total, 813 patients were included in this study. Their use of healthcare services and the accompanying expenses were higher than the national medians for similar age groups; however, both metrics decreased in the second year. The major causes of admission within 2 years of surgery were respiratory and neurological diseases. The mortality rate within 2 years was 37.8%. Higher risks of mortality were associated with having two or more complex chronic conditions. Use of home healthcare nursing services was associated with a lower mortality risk.

CONCLUSION

Paediatric patients with more complex chronic conditions tended to have higher mortality rates within 2 years after surgery. However, receiving home healthcare nursing was significantly associated with a reduced risk of death. Many causes of hospitalisation may be preventable with education and supportive care. Therefore, further research for establishing an integrated care system for these patients and their caregivers is required.

Clinical characteristics of the "Gap" between the prevalence and incidence of hearing loss using National Health Insurance Service data

OBJECTIVES

Hearing loss is the inability to hear speech or sounds well, owing to a number of causes. This study aimed to simultaneously determine the prevalence, incidence, and the Gap between them in hearing loss in South Korean patients at the same point in time as well as to identify patients who have not recovered from hearing loss.

METHODS

We examined the prevalence and incidence of patients diagnosed with hearing loss in the National Health Insurance Service database over an 11-year period from 2010 to 2020. The difference between the prevalence and the incidence was defined in this study as the term "Gap". Gap is the number of patients converted into the number of patients per 100,000 people by subtracting the incidence from the prevalence. Clinical characteristics such as sex and age per 100,000 individuals were examined.

RESULTS

As of 2020, the domestic prevalence obtained in this study was 1.84%, increasing annually, and the prevalence increased with age to 4.10% among those over 60. The domestic incidence was 1.57%, increasing annually, and the incidence increased with age to 3.36% for those over 60s. The Gap was 0.27%, showing a steady increase from 2011 to 2020 with a corresponding increase in insurance benefit expenses.

CONCLUSION

To fully understand the burden of hearing loss and develop effective prevention and treatment strategies, it is important to measure the Gap between its prevalence and incidence. This Gap means a lot because hearing loss is an irreversible disease. Gap represents patients who have already been diagnosed with hearing loss and are being diagnosed every year, indicating that the number of patients who do not recover is increasing. In other words, the increase in Gap meant that there were many patients who constantly visited the hospital for diagnosis of hearing loss.

Risk of thromboembolism according to statin treatment in patients with cancer: A nationwide nested case-control study

BACKGROUND

Thromboembolic events exhibit increased prevalence in patients with cancer and can negatively affect prognoses. We investigated whether statin treatment would reduce thromboembolic risk in patients with cancer.

METHODS

We conducted a nested case-control study using a Korean nationwide health claims database. The study included patients newly diagnosed with cancer without a prior history of cardiovascular disease between 2014 and 2016. Cases who developed arterial thromboembolism (ATE) or venous thromboembolism (VTE) after cancer diagnosis and three individually matched controls were selected. Conditional logistic regression was used to assess the association between thromboembolic risk and statin therapy after cancer diagnosis.

RESULTS

Among 455,805 newly diagnosed patients with cancer followed for a mean of 4.3 ± 2.0 years, 22,249 patients developed thromboembolic events (ATE: 6341, VTE: 15,908), resulting in an incidence rate of 1133 per 100,000 person-years. The nested case-control study included 21,289 cases with thromboembolic events and 63,867 controls. Statin use was less frequent in the case group (18.0 % vs. 23.7 %). Statin treatment was associated with a lower risk of thromboembolic events (adjusted odds ratio [OR] 0.70; 95 % confidence interval [CI] 0.67-0.73). This association was observed for both ATE (adjusted OR 0.68; 95 % CI 0.63-0.74) and VTE (adjusted OR 0.71; 95 % CI 0.67-0.75). Longer statin use and better adherence were also associated with lower risk for thromboembolic events. Statin treatment was significantly associated with fewer thromboembolic events in most cancer types.

CONCLUSIONS

Statin use was associated with lower risk for thromboembolic events in patients newly diagnosed with cancer.

Associations of omega-3 fatty acids vs. fenofibrate with adverse cardiovascular outcomes in people with metabolic syndrome: propensity matched cohort study

AIMS

Omega-3 fatty acids and fenofibrates have shown some beneficial cardiovascular effects; however, their efficacy has not been compared. This study aimed to compare the effectiveness of currently available omega-3 fatty acids and fenofibrate for reducing major adverse cardiovascular events (MACE).

METHODS AND RESULTS

From a nationwide population-based cohort in South Korea (2008-2019), individuals with metabolic syndrome (≥30 years) who received statin with omega-3 fatty acids and those receiving statin with fenofibrate were matched by propensity score (n = 39 165 in both groups). The primary outcome was MACE, including ischaemic heart disease (IHD), ischaemic stroke (IS), and death from cardiovascular causes. The risk of MACE was lower [hazard ratio (HR), 0.79; 95% confidence interval (CI), 0.74-0.83] in the fenofibrate group than in the omega-3 fatty acid group. Fenofibrate was associated with a lower incidence of IHD (HR, 0.72; 95% CI, 0.67-0.77) and hospitalization for heart failure (HR, 0.90; 95% CI, 0.82-0.97), but not IS (HR, 0.90; 95% CI, 0.81-1.00) nor death from cardiovascular causes (HR, 1.07; 95% CI, 0.97-1.17). The beneficial effect of fenofibrate compared to omega-3 fatty acids was prominent in patients with preexisting atherosclerotic cardiovascular disease and those receiving lower doses of omega-3 fatty acids (≤2 g per day).

CONCLUSION

In a real-world setting, fenofibrate use was associated with a lower risk of MACE compared with low-dose omega-3 fatty acids when added to statins in people with metabolic syndrome.

Impact of coronavirus disease 2019 on cancer care: How the pandemic has changed cancer utilization and expenditures

PURPOSE

Since identified in December 2019, the novel coronavirus disease 2019 (COVID-19) has had a global impact on medical resource use and costs for patients with cancer in South Korea. This study aimed to identify the medical use and costs among patients with cancer during the COVID-19 pandemic, to predict these patterns in South Korea in the future.

METHODS

We conducted a secondary claims data analysis using the National Health Insurance Service database for the calendar period of 2019-2020. Monthly relative percent changes in cancer incidence, medical use, and billing costs for medical care utilization by cancer type were calculated. Then, the medical use and costs after January 2020 were predicted using a time series model with data before the COVID-19 outbreak (2014-2019).

RESULTS

The incidence of cancer diagnoses has seen a notable decline since the outbreak of the COVID-19 in 2020 as compared to 2019. Despite the impact of COVID-19, there hasn't been a distinct decline in outpatient utilization when compared to inpatient utilization. While medical expenses for both inpatient and outpatient visits have slightly increased, the number of patients treated for cancer has decreased significantly compared to the previous year. In June 2020, overall outpatient costs experienced the highest increase (21.1%), while individual costs showed the most significant decrease (-4.9%) in June 2020. Finally, the number of hospitalisations and outpatient visits increased slightly from June-July in 2020, reducing the difference between the actual and predicted values. The decrease in the number of inpatient hospitalisations (-22~-6%) in 2020 was also high.

CONCLUSIONS

The overall use of medical services by patients with cancer decreased in 2020 compared with that in the pre-COVID-19 pandemic period. In the future, the government should consider how to recover from the COVID-19 pandemic, and establish permanent health policies for patients with cancer.

Prediction of Cardiovascular Complication in Patients with Newly Diagnosed Type 2 Diabetes Using an XGBoost/GRU-ODE-Bayes-Based Machine-Learning Algorithm

BACKGRUOUND

Cardiovascular disease is life-threatening yet preventable for patients with type 2 diabetes mellitus (T2DM). Because each patient with T2DM has a different risk of developing cardiovascular complications, the accurate stratification of cardiovascular risk is critical. In this study, we proposed cardiovascular risk engines based on machine-learning algorithms for newly diagnosed T2DM patients in Korea.

METHODS

To develop the machine-learning-based cardiovascular disease engines, we retrospectively analyzed 26,166 newly diagnosed T2DM patients who visited Seoul St. Mary's Hospital between July 2009 and April 2019. To accurately measure diabetes-related cardiovascular events, we designed a buffer (1 year), an observation (1 year), and an outcome period (5 years). The entire dataset was split into training and testing sets in an 8:2 ratio, and this procedure was repeated 100 times. The area under the receiver operating characteristic curve (AUROC) was calculated by 10-fold cross-validation on the training dataset.

RESULTS

The machine-learning-based risk engines (AUROC XGBoost=0.781±0.014 and AUROC gated recurrent unit [GRU]-ordinary differential equation [ODE]-Bayes=0.812±0.016) outperformed the conventional regression-based model (AUROC=0.723± 0.036).

CONCLUSION

GRU-ODE-Bayes-based cardiovascular risk engine is highly accurate, easily applicable, and can provide valuable information for the individualized treatment of Korean patients with newly diagnosed T2DM.

Helicobacter pylori Treatment and Gastric Cancer Risk After Endoscopic Resection of Dysplasia: A Nationwide Cohort Study

BACKGROUND & AIMS

The study investigated the association between Helicobacter pylori treatment and the risk of gastric cancer after endoscopic resection of gastric dysplasia.

METHODS

Patients who received endoscopic resection for gastric dysplasia between 2010 and 2020 from Korean nationwide insurance data were included. We verified the occurrence of new-onset gastric cancer and metachronous gastric neoplasm, which encompasses both cancer and dysplasia, >1 year after the index endoscopic resection. Newly diagnosed gastric cancer ≥3 years and ≥5 years was regarded as late-onset gastric cancer. A multivariable Cox regression model with H pylori treatment status as a time-dependent covariate was used to determine the risk of gastric cancer and metachronous gastric neoplasms.

RESULTS

Gastric dysplasia in 69,722 patients was treated with endoscopy, and 49.5% were administered H pylori therapy. During the median 5.6 years of follow-up, gastric cancer developed in 2406 patients and metachronous gastric neoplasms developed in 3342 patients. Receiving H pylori therapy was closely related to lower gastric cancer risk (adjusted hazard ratio [aHR], 0.88; 95% confidence interval [CI], 0.80-0.96). H pylori treatment also significantly decreased metachronous gastric neoplasm development (aHR, 0.76; 95% CI, 0.70-0.82). Furthermore, H pylori therapy showed a prominent protective effect for late-onset gastric cancer development at ≥3 years (aHR, 0.84; 95% CI, 0.75-0.94) and ≥5 years (aHR, 0.80; 95% CI, 0.68-0.95).

CONCLUSIONS

In this nationwide cohort, H pylori therapy after endoscopic resection of gastric dysplasia was associated with a reduced risk of gastric cancer and metachronous gastric neoplasm occurrence.

Understanding the long-term impact of incident osteoporotic fractures on healthcare utilization and costs in Korean postmenopausal women

This study provides long-term evidence that healthcare resource utilization and costs of care in women who experienced incident osteoporotic fractures remained higher than those in women without fractures over a span of 5 years. These findings emphasize the importance of early diagnostics and treatment for osteoporosis.

PURPOSE

To evaluate healthcare resource utilization (HCRU) and costs of care over 5 years after the incident osteoporotic fractures (OF) in postmenopausal women.

METHODS

We used data from the National Health Insurance Service databases 2011-2018. Women aged ≥ 50 years with incident OF (OF group) were matched to women without OF (non-OF group). HCRU (inpatient, outpatient, and emergency room [ER] visits) and costs of care (inpatient, outpatient, and ER visits) during the 5-year follow-up period were derived after propensity score matching (PSM). Additionally, we identified women with subsequent fractures within the first 2 years after the incident OF.

RESULTS

After PSM, 47,238 OF and 134,813 non-OF women were identified. HCRU rates and costs of care were highest in the first year after OF and decreased substantially, but remained higher in the OF group during the entire follow-up period. The increase in cumulative HCRU rates over 5 years was highest in inpatient admissions with ER visits (138% higher in OF vs non-OF). The cumulative total costs over 5 years were 73% higher in the OF group than in the non-OF group, which was mostly driven by inpatient costs. Trends were similar for women with subsequent fractures, but they generally showed higher HCRU and costs than those in the total OF group.

CONCLUSION

OF imposes a substantial and sustained economic burden on women, resulting in an approximately twofold increase in the cumulative cost over 5 years compared to women without fracture, which highlights the need for early diagnostics and treatment of osteoporosis.

Association between selective serotonin reuptake inhibitor use and developing irritable bowel syndrome through retrospective analysis

BACKGROUND AND AIM

Serotonin affects the balance and integrity of the gut microbiome; however, studies have confirmed the influence of selective serotonin reuptake inhibitors (SSRIs) on irritable bowel syndrome (IBS). We evaluated the association between SSRI use and subsequent IBS occurrence in a real-world setting.

METHODS

A multivariate Cox proportional hazard model was adopted, and the National Health Insurance Service cohort claims database between 2010 and 2019 was used. Non-SSRI users were selected using the propensity score matching method. Subgroup analyses were performed using the point of use, cumulative dose, and duration of SSRI use. Additional analysis was performed using a control group without psychiatric medications.

RESULTS

We included 2901 SSRI users and 2727 non-SSRI users. After adjusting covariates, the risk of developing IBS in SSRI users was 1.54 times that in non-SSRI users (95% confidence interval [CI]: 1.01-2.33). The hazard ratio (HR) of the recent, heavy, and short-term user groups were 3.19 (95% CI: 2.03-4.99), 2.22 (95% CI: 1.50-3.29), and 4.83 (95% CI: 3.02-7.73), respectively, compared with that of non-users. In patients without a history of psychiatric medications, the risk of IBS incidence after SSRI use increased significantly (HR: 1.61, 95% CI: 1.06-2.42), whereas HR was insignificant in patients with a history of psychiatric medications (HR: 1.25, 95% CI: 0.98-1.60).

CONCLUSIONS

The risk of subsequent IBS occurrence following SSRI use was high in patients who initially took a heavy SSRI dose and those who did not have a history of psychiatric drug use.

Disability-Related Mortality Inequity in South Korea: Comparison in Terms of Seoul Metropolitan/Non-Metropolitan Areas and Income Levels

Despite the improved living standards in South Korea, people with disabilities still experience health disparities. Therefore, we analyzed differences in mortality rates among people with disabilities according to income level and residential area using representative data from the National Health Insurance Service in South Korea. Descriptive statistics and Cox proportional risk models were used to identify the risk factors for mortality affecting people with disabilities stratified by income level and residential area. Those living in non-metropolitan areas and low-income households had high mortality risks, suggesting that income level and residential area were related to mortality risk. The mortality risk of those with a high-income level was 1.534 times higher in non-metropolitan areas than in Seoul metropolitan areas (95% confidence interval [CI] = 1.44-1.63). Among people with low income living in non-metropolitan areas, the crude hazard ratios of mortality risk were 1.26 (95% CI = 1.14-1.39), 1.44 (95% CI = 1.34-1.54), and 1.39 (95% CI = 1.20-1.61) for those with brain lesions, sensory impairment (visual/hearing/speech impairment), and kidney failure, respectively. No significant differences were observed between people with autism in non-metropolitan and Seoul metropolitan areas and those with low- and high-income levels. Health issues and countermeasures are crucial to reduce mortality risk among people with disabilities.

Demographic and clinical characteristics associated with screening practices for hydroxychloroquine retinopathy

In this nationwide population-based cohort study, we investigated the demographic and clinical characteristics associated with hydroxychloroquine retinopathy screening using the National Health Insurance Review and Assessment database in South Korea. This study included a total of 32,732 at-risk patients, identified based on having been prescribed hydroxychloroquine for at least 6 months, and 15,477 long-term (> 5 years) users between January 2010 and December 2020. Participants were categorized based on the performance of baseline examinations (within 1 year of hydroxychloroquine use) and monitoring examinations (after 5 years of hydroxychloroquine use). Demographic and clinical factors, including hospitals and medical specialties prescribing hydroxychloroquine, indications for hydroxychloroquine use, and prescription details, were compared between groups. Significant differences were found in sex, residence, departments and hospitals (primary vs. referral centers) where hydroxychloroquine was prescribed, diagnosis for hydroxychloroquine therapy, and mean daily dose between patients who did and did not undergo baseline or monitoring examinations (all P < 0.01). Patients who received hydroxychloroquine prescriptions from referral hospitals were more likely to undergo baseline and monitoring examinations compared to those from primary clinics (both P < 0.001). Additionally, patients who received hydroxychloroquine prescriptions from the rheumatology department and had systemic lupus erythematosus were more likely to undergo baseline and monitoring examinations compared to other patients (all P < 0.001). There were notable differences in the number of modalities used for retinopathy screening between primary and referral centers (P < 0.001). Our findings suggest that several clinical factors related to hydroxychloroquine prescription and screening centers are associated with retinopathy screening practices.

Statin therapy in individuals with intermediate cardiovascular risk

BACKGROUND

As intermediate cardiovascular risk group accounts for a large part of the total population, determining appropriate cholesterol target in this population is critical. Herein, we investigated the optimal low-density lipoprotein cholesterol (LDL-C) level in individuals with intermediate cardiovascular risk after statin therapy.

METHODS

This was a nationwide observational and validation cohort study (median duration of follow-up: 7.5 and 8.7 years, respectively), using data from the Korean National Health Insurance Service and a tertiary hospital database. Among individuals who underwent regular health examinations, those with ≥2 cardiovascular risk factors except diabetes mellitus, LDL-C 100-189 mg/dL, and newly used statins were enrolled. Of the 358,694 screened people, 57,594 met the inclusion criteria, of whom 27,793 were finally analyzed. The study population was stratified according to post-treatment LDL-C levels as follows: <100, 100-119, 120-139, and ≥ 140 mg/dL. The primary outcome variable was composite cardiovascular events (myocardial infarction, coronary revascularization, and ischemic stroke). From the patients screened of Severance Hospital cohort, 1859 meeting inclusion criteria were used for validation.

RESULTS

The rates of composite events ranged from 7.74 to 9.10 (mean 8.38)/1000 person-years in the three lower LDL-C groups. Adjusted hazard ratios (aHRs) ranged from 0.78 to 0.95 in the three groups with lower LDL-C, and a lower event risk was more evident in the groups that achieved LDL-C levels <120 mg/dL (p = 0.001-0.009). The total mortality risk did not differ between groups. In the validation cohort, the mean rate of composite events was 10.83/1000 person-years. aHRs ranged from 0.52 to 0.78 in the groups with lower LDL-C, and a lower risk was more obvious in patients who achieved LDL-C levels <100 mg/dL (p = 0.006-0.03).

CONCLUSIONS

Individuals with intermediate cardiovascular risk who achieved LDL-C levels <120 mg/dL after statin therapy had lower event risk. This result provides clinically useful evidence on target LDL-C levels in this population.

Increased Risk of Osteoporotic Fracture in Patients With Autoimmune Hepatitis

INTRODUCTION

Few large-scale studies have been published regarding the association between autoimmune hepatitis (AIH) and risk of osteoporotic fracture. This study aimed to determine the risk of developing an osteoporotic fracture in patients with AIH.

METHODS

We used claims data from the Korean National Health Insurance Service between 2007 and 2020. Patients with AIH (n = 7,062) were matched with controls (n = 28,122) based on age, sex, and duration of follow-up using a ratio of 1:4. Osteoporotic fractures included fractures of the vertebrae, hip, distal radius, and proximal humerus. The incidence rate (IR) and IR ratio of osteoporotic fracture were compared between the 2 groups, and their associated factors were evaluated.

RESULTS

During a median follow-up period of 5.4 years, 712 osteoporotic fractures occurred in patients with AIH with an IR of 17.5 per 1,000 person-years. Patients with AIH had a significantly higher risk of osteoporotic fractures than matched controls, with an IR ratio of 1.24 (95% confidence intervals, 1.10-1.39, P < 0.01) in the multivariable analysis. Female sex, older age, history of stroke, presence of cirrhosis, and use of glucocorticoids were associated with an increased risk of osteoporotic fractures. In the 2-year landmark analysis, longer duration of glucocorticoid exposure was associated with an incremental increased risk of osteoporotic fracture.

DISCUSSION

Patients with AIH had an increased risk of osteoporotic fracture compared with controls. The presence of cirrhosis and long-term use of glucocorticoids further adversely affected osteoporotic fracture in patients with AIH.

Association between subconjunctival hemorrhage and hemorrhagic disorders: a nationwide population-based study

Subconjunctival hemorrhage (SCH) is a benign eye condition that is often noticeable and leads to medical attention. Despite previous studies investigating the relationship between SCH and cardiovascular diseases, the relationship between SCH and bleeding disorders remains controversial. In order to gain further insight into this association, a nationwide cohort study was conducted using data from the National Health Insurance Service-National Sample Cohort version 2.0 from 2006 to 2015. The study defined SCH using a diagnostic code and compared the incidence and risk factors of intracerebral hemorrhage (ICH) and gastrointestinal (GI) bleeding in 36,772 SCH individuals and 147,088 propensity score (PS)-matched controls without SCH. The results showed that SCH was associated with a lower risk of ICH (HR = 0.76, 95% CI = 0.622-0.894, p = 0.002) and GI bleeding (HR = 0.816, 95% CI = 0.690-0.965, p = 0.018) when compared to the PS-matched control group. This reduced risk was more pronounced in females and in the older age group (≥ 50 years), but not observed in males or younger age groups. In conclusion, SCH dose not increase the risk of ICH and major GI bleeding and is associated with a decreased incidence in females and individuals aged ≥ 50 years.

Impact of guideline-directed medical therapy on 5-year mortality in patients with newly diagnosed peripheral artery disease

OBJECTIVE

Current guidelines recommend that patients with peripheral artery disease (PAD) should be treated with antithrombotic agents, renin-angiotensin-system blockers, and statins. However, the clinical impact of guideline-directed medical therapy (GDMT) on long-term mortality in patients with newly diagnosed PAD remains unclear. We aimed to investigate the prevalence of GDMT and evaluate 5-year mortality according to GDMT after PAD diagnosis.

METHODS

This retrospective cohort study, using nationwide health insurance claims data in Korea, included patients newly diagnosed with PAD between 2006 and 2015. GDMT was defined as the use of all drugs, including antithrombotic agents, renin-angiotensin-system blockers, and statins, within 3 months of PAD diagnosis. The primary endpoint was all-cause mortality.

RESULTS

We investigated 19,561 newly diagnosed patients with PAD without proven cardiovascular disease. Among the study population, 4378 patients (22.4%) were categorized in the GDMT and 15,183 (77.6%) in the non-GDMT groups. During the 5-year follow-up, GDMT showed a lower incidence of all-cause mortality than that of non-GDMT (2.8% vs 4.8%; adjusted hazard ratio, 0.329; 95% confidence interval, 0.257-0.421; P < .001). Even in the propensity-matched population, GDMT showed a lower mortality rate than non-GDMT (hazard ratio, 0.283; 95% confidence interval, 0.217-0.370; P < .001). As the number of guideline-recommended drugs increased, the mortality rate decreased proportionately.

CONCLUSIONS

After PAD diagnosis, GDMT was associated with a lower incidence of mortality regardless of proven cardiovascular disease. This retrospective analysis showed an insufficient prevalence of GDMT among patients with PAD in real-world practice.

Headaches during pregnancy and the risk of subsequent stroke

BACKGROUND

Primary headache disorder is a known risk factor for stroke in women and usually improves during the first trimester of pregnancy. However, despite this, some women develop headaches during pregnancy (G-HA), and the effect of this headache on subsequent stroke is unknown. In this study, we evaluated the association between G-HA and stroke after delivery in women.

METHODS

Based on the Korean National Health Insurance Service database, we included women hospitalized for delivery between 2012 and 2013. G-HA was defined as a headache diagnosed during pregnancy. Primary outcome was any stroke that occurred during the observational periods from delivery to December 31, 2020. All diseases were identified based on data registered in the database using the International Classification of Disease-10th Revision-Clinical Modification codes.

RESULTS

Of 906,187 pregnant women, G-HA was found in 56,813 (6.3%). During the observational periods, the G-HA ( +) group had a significantly higher risk of any stroke [adjusted hazard ratio (aHR) = 1.59, 95% confidence interval (CI): 1.30-1.95], ischemic stroke (aHR = 1.50, 95% CI: 1.12-2.01), hemorrhagic stroke (aHR = 1.63, 95% CI: 1.23-2.15), and intracerebral hemorrhage (aHR = 1.63, 95% CI: 1.19-2.23) than the G-HA (-) group. When analyzed considering the interaction with history of headache disorder, G-HA showed a significant association with hemorrhagic stroke, but lost its effect on ischemic stroke.

CONCLUSIONS

We demonstrated that G-HA was associated with subsequent stroke occurrence after delivery. However, the relationship between G-HA and ischemic stroke is mitigated by a history of pre-pregnancy headache disorder.

Association between initial continuity of care status and diabetes-related health outcomes in older patients with type 2 diabetes mellitus: A nationwide retrospective cohort study in South Korea

BACKGROUND AND AIM

Timely and continuous care is necessary for patients with diabetes to prevent hospitalization and complications. This study investigated the association between initial Continuity of Care Index (COCI) status after diagnosis of type 2 diabetes mellitus (T2DM) and short- and long-term diabetes-related health outcomes.

METHODS

It targeted elderly patients aged 60 years and above diagnosed with T2DM and used the National Health Insurance Service Senior cohort data from 2008 to 2019. The outcome measures were diabetic avoidable hospitalization and diabetic complication incidence for a five-year period. The main independent variable was the first-year COCI status after T2DM diagnosis. Survival analyses were performed using the Cox proportional hazards model.

RESULTS

Participants with a good COCI status within the first year of being diagnosed with T2DM experienced a reduced risk of diabetes-induced avoidable hospitalization (five years: Hazard ratio (HR) 0.39, 95 % Confidence interval (CI) 0.27-0.57; overall period: HR 0.56, 95 % CI 0.43-0.72) and diabetic complications (five years: HR 0.74, 95 % CI 0.68-0.80; overall period: HR 0.77, 95 % CI 0.71-0.82).

CONCLUSIONS

In the short- and long-term, there is a need for early management and improved healthcare accessibility of diabetes to prevent diabetes-avoidable hospitalization and diabetes-related complications.

Influenza viral infection is a risk factor for severe illness in COVID-19 patients: a nationwide population-based cohort study

In order to prepare for the twindemic of influenza and SARS-CoV-2 infection, we investigated the association between influenza infection and subsequent severity of SARS-CoV-2 infection. A population-based nationwide cohort study was performed using data from the National Health Insurance Service (NHIS) in the Republic of Korea. This study included 274,126 individuals who underwent SARS-CoV-2 PCR testing between 20 January 2020 and 1 October 2020. Among these patients, 28,338 tested positive for SARS-CoV-2, and 4,003 of these individuals had a history of influenza. The control group was selected through 1:1 propensity score matching. In the group of 4,003 COVID-19-positive individuals with no history of influenza, 192 (4.8%) experienced severe illness from COVID-19 infection. In the group of 4,003 COVID-19-positive individuals with a history of influenza, 260 (6.5%) had severe illness from COVID-19, and the overall adjusted odds ratio (aOR) was 1.29 (95% confidence interval 1.04-1.59). Among the 4,003 COVID-19-positive individuals with a history of influenza, severe COVID-19 infection was experienced by 143 of 1,760 (8.1%) with an influenza history within 1 year before the onset of COVID-19, 48 of 1,129 (4.3%) between 1 and 2 years, and 69 of 1,114 (6.2%) between 2 and 3 years before COVID-19 onset, and the aORs were 1.54 (1.20-1.98), 1.19 (0.84-1.70), and 1.00 (0.73-1.37), respectively. In conclusion, individuals who had an influenza infection less than 1 year before COVID-19 infection were at an increased risk of experiencing severe illness from the SARS-CoV-2 infection. To control the public health burden, it is essential that effective public health control measures, which include influenza vaccination, hand washing, cough etiquette, and mask use are in place.

Characteristics of the Mycoplasma pneumoniae Epidemic from 2019 to 2020 in Korea: Macrolide Resistance and Co-Infection Trends

Mycoplasma pneumoniae, a major etiological agent of community-acquired pneumonia, exhibits distinct cyclic epidemic patterns recurring every three to five years. Several cases of co-infection with severe acute respiratory syndrome coronavirus 2 have been reported globally, resulting in unfavorable clinical manifestations. This study investigated the epidemiological features of the recent M. pneumoniae outbreak (May 2019-April 2020) using retrospective data from the last five years. Molecular test data for macrolide resistance and co-infection were obtained from the Seegene Medical Foundation. National medical expenditure and hospitalization rates were analyzed using data from The Health Insurance Review and Assessment Service of Korea. The macrolide resistance rate was 69.67%, peaking at 71.30% during the epidemic period, which was considerably higher than the 60.89% rate during non-epidemic periods. The co-infection rate with other respiratory pathogens was 88.49%; macrolide-resistant M. pneumoniae strains showed a 2.33% higher co-infection rate than the susceptible strains. The epidemic period had 15.43% higher hospitalization and 78.27% higher medical budget expenditure per patient than non-epidemic periods. The increased rates of macrolide resistance and co-infection observed in macrolide-resistant M. pneumoniae during the epidemic period highlight the importance of monitoring future outbreaks, especially considering macrolide resistance and the risk of co-infection with other pathogens.

The role of income and frequency of dental visits in the relationship between dental sealant use and resin fillings after extended coverage: a retrospective cohort study

BACKGROUND

Prevention and treatment services use is closely associated with socioeconomic factors, such as income. This study aimed to investigate the relationship between implementing the sealant program and resin fillings restoration and to explore the role of income and frequency of dental visits in this relationship.

METHODS

This retrospective cohort study used the cohort database from the National Health Information Database of the National Health Insurance Service. The study population comprised 494,731 children born in 2007. A logistic regression model for the experience of resin fillings and a linear regression model for weighted utilization of them were used to identify the independent effects of dental sealants, income, and frequency of dental visits. All analyses were conducted using the SAS Enterprise Guide version 7.1 (SAS Institute Inc., Cary, NC, USA).

RESULTS

The ratio based on income level was almost proportional in all groups except the medical aid group, which had a rate as high as that of the wealthier group. Children without sealants were 1.05 times more likely to have resin fillings than others after adjusting for income level and frequency of visiting dental clinics in the final model. However, an opposite relationship between sealant experiences and resin fillings was observed in the previous model without dental visits. The gap in the weighted resin filling scores according to socioeconomic variables showed a similar tendency.

CONCLUSIONS

Income and frequency of dental visits might be confounding factors for the relationship between dental sealant and resin fillings. It is necessary to consider the complex relationship between socioeconomic indicators and service use while studying oral health inequality.

Effectiveness and Safety of COVID-19 Vaccination During Preconceptional and Preclinical Pregnancy Period: A National Population Study

BACKGROUND

We aimed to assess the risk of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and early abortive outcomes after the association between coronavirus disease 2019 (COVID-19) vaccination during the preconceptional period and preclinical pregnancy, which are likely to be inadvertent vaccination.

METHODS

We used data from the Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort from December 2020 to December 2021. The vaccinated pregnant women were matched to unvaccinated pregnant controls at a 1:4 ratio. The risks of SARS-CoV-2 infection and intensive care unit (ICU) admission within 14 days of infection were analyzed to assess its effectiveness. For safety measures, the adjusted relative risks (aRRs) of early abortive outcomes for the first COVID-19 vaccination during the preconceptional and preclinical periods were calculated considering covariates. We compared the risk of early abortion between mRNA and viral vector vaccines.

RESULTS

The overall COVID-19 vaccination rates during the preconceptional period and preclinical pregnancy were 3.1% (6,662/215,211) and 2.6% (5,702/215,211), respectively. The cumulative incidence of ICU admission within 14 days of SARS-CoV-2 infection was 6/100,000 in the unvaccinated group, whereas there were no ICU admissions in the vaccinated groups. The risks of early abortive outcomes were not significantly different between the preconceptional vaccination group and the unvaccinated group (aRR, 1.04; 95% confidence interval [CI],0.99-1.10) or between preclinical pregnancy vaccination and their matched controls (1.02; 95% CI, 0.96-1.08). mRNA and viral vector vaccines have shown similar risks for early abortive outcomes and miscarriages.

CONCLUSION

Our findings have provided compelling evidence regarding the effectiveness and safety of COVID-19 vaccination prior to and during early pregnancy. Further research is required to extend the safety and efficacy profiles of COVID-19 vaccines to pregnant women and their babies.

Exploring Utilization and Establishing Reference Intervals for the Apolipoprotein B Test in the Korean Population

We investigated the reference intervals for Apolipoprotein B (ApoB), a valuable biomarker for cardiovascular diseases, in Korean adults who had undergone health check-ups and showed normal lipid levels under traditional lipid tests, including total cholesterol, triglyceride, and high-density lipoprotein cholesterol, along with ApoB. We compared the findings with different cutoffs for ApoB from international clinical guidelines. Among a total of 264,105 traditional lipid test sets, only 464 (0.2%) included ApoB tests, indicating underutilization of this test in health check-up clinics in Korea. From these 464 samples, 334 ApoB results (164 men and 170 women) with normal traditional lipid test results were used to establish reference intervals. Using the parametric method (mean ± 2 SD), the reference intervals ranged from 46 to 134 mg/dL for men and 49 to 129 mg/dL for women. Employing the non-parametric method (central 95th percentile value), the reference intervals ranged from 50 to 131 mg/dL for men and 51 to 127 mg/dL for women. The prevalence of high ApoB did not significantly differ by sex when considering the established reference intervals for each sex and the cutoffs recommended by international clinical guidelines. This study enhances knowledge on ApoB reference intervals in the Korean population, and it will in aid test result interpretation for clinicians and laboratories.

Effectiveness and safety of secondary prevention of non-vitamin K oral anticoagulants use by drug type in Asian patients

BACKGROUND

Although widely used in clinical fields, real-world data on the role of warfarin and non-vitamin K oral anticoagulants (NOACs) for the secondary prevention of thromboembolic complications in ischemic stroke patients with nonvalvular atrial fibrillation (NVAF) are scarce.

AIMS

This retrospective cohort study compared the effectiveness and safety of secondary prevention of NOAC and warfarin in ischemic stroke patients with NVAF.

METHODS

From the Korean National Health Insurance Service Database, we included 16,762 oral anticoagulants-naive acute ischemic stroke patients with NVAF between July 2016 and June 2019. The main outcomes included ischemic stroke, systemic embolism, major bleeding, and all-cause of death.

RESULTS

In total, 1717 warfarin and 15,025 NOAC users were included in the analysis. After 1:8 propensity score matching, during the observation period, all types of NOACs had a significantly lower risk of ischemic stroke and systemic embolism than warfarin (edoxaban: adjusted hazard ratio [aHR], 0.80; 95% confidence interval [CI], 0.68-0.93, rivaroxaban: aHR, 0.82; 95% CI, 0.70-0.96, apixaban: aHR, 0.79; 95% CI, 0.69-0.91, and dabigatran: aHR, 0.82; 95% CI, 0.69-0.97). Edoxaban (aHR, 0.77; 95% CI, 0.62-0.96), apixaban (aHR, 0.73; 95% CI, 0.60-0.90), and dabigatran (aHR, 0.66; 95% CI, 0.51-0.86) had lower risks of major bleeding and all-cause of death.

CONCLUSIONS

All NOACs were more effective than warfarin in the secondary prevention of thromboembolic complications in ischemic stroke patients with NVAF. Except for rivaroxaban, most NOACs demonstrated a lower risk of major bleeding and all-cause of death than warfarin.

Proton pump inhibitor use and the risk of metachronous gastric cancer after H. pylori eradication in patients who underwent endoscopic resection for gastric neoplasms: A population-based cohort study

BACKGROUND

The association between proton pump inhibitors (PPI) use and gastric cancer remains controversial.

AIMS

To investigate the impact of long-term PPI use on metachronous gastric cancer after Helicobacter pylori eradication in high-risk patients who underwent endoscopic resection of gastric neoplasms.

METHODS

Using the Korean National Health Insurance Services database, we identified 1836 PPI users and 12,218 non-users among patients who received H. pylori eradication therapy after endoscopic resection for gastric neoplasms between 2009 and 2014. We then compared the incidence of metachronous gastric cancer between the PPI user and non-user groups. We conducted sensitivity analysis using various time lags and propensity score-matched analysis to ensure the robustness of the results.

RESULTS

After a median follow-up of 7.3 years, the incidence of metachronous gastric cancer was significantly higher in the PPI user group than in the non-user group, with a crude hazard ratio of 6.20 (95% confidence interval, 5.78-6.65). After adjustment, PPI use was associated with the development of metachronous gastric cancer, with an adjusted hazard ratio of 5.51 (95% confidence interval, 5.12-5.92). The PPI user group was categorised into three subgroups according to the cumulative PPI dose; the increased risk of metachronous gastric cancer remained significant regardless of the PPI dose. Moreover, these results remained robust after applying various time lags and propensity score-matched analyses.

CONCLUSIONS

Long-term PPI use is associated with an increased risk of metachronous gastric cancer in patients who undergo H. pylori eradication therapy after endoscopic resection of gastric neoplasms.

Risk of Subsequent Primary Cancer in Thyroid Cancer Survivors: A Nationwide Population-Based Study

Background: Despite obtaining a good prognosis and long life expectancy, survivors of thyroid cancer can nevertheless develop subsequent primary cancer (SPC). We investigated the risk and types of SPC in patients with thyroid cancer and compared them with subjects without thyroid cancer history (controls). Methods: We conducted a nationwide, population-based, retrospective cohort study based on the Korean National Health Insurance Database. A total of 432,654 patients diagnosed with thyroid cancer between 2004 and 2019 were 1:1 matched with controls for age, sex, income, and region of residence. The hazard ratios (HR) and 95% confidence intervals (CI) of SPC were estimated using Cox proportional hazard models. Results: In total, 78,584 (18.2%) patients with thyroid cancer and 49,979 (11.6%) controls were diagnosed with SPCs over a mean follow-up of 6.9 years. Patients with thyroid cancer had a higher risk of SPC at any site (adjusted HR, 1.62; 95% CI, 1.60-1.64) than the controls. The risk of SPCs was particularly high for patients diagnosed with thyroid cancer at a younger age (<40 years) and within 5 years. Conclusions: Medical caregivers should consider the long-term follow-up of patients with thyroid cancer and discuss the risk of SPC, especially if they complain of cancer-related symptoms.

Exploring patient medication adherence and data mining methods in clinical big data: A contemporary review

BACKGROUND

Increasingly, patient medication adherence data are being consolidated from claims databases and electronic health records (EHRs). Such databases offer an indirect avenue to gauge medication adherence in our data-rich healthcare milieu. The surge in data accessibility, coupled with the pressing need for its conversion to actionable insights, has spotlighted data mining, with machine learning (ML) emerging as a pivotal technique. Nonadherence poses heightened health risks and escalates medical costs. This paper elucidates the synergistic interaction between medical database mining for medication adherence and the role of ML in fostering knowledge discovery.

METHODS

We conducted a comprehensive review of EHR applications in the realm of medication adherence, leveraging ML techniques. We expounded on the evolution and structure of medical databases pertinent to medication adherence and harnessed both supervised and unsupervised ML paradigms to delve into adherence and its ramifications.

RESULTS

Our study underscores the applications of medical databases and ML, encompassing both supervised and unsupervised learning, for medication adherence in clinical big data. Databases like SEER and NHANES, often underutilized due to their intricacies, have gained prominence. Employing ML to excavate patient medication logs from these databases facilitates adherence analysis. Such findings are pivotal for clinical decision-making, risk stratification, and scholarly pursuits, aiming to elevate healthcare quality.

CONCLUSION

Advanced data mining in the era of big data has revolutionized medication adherence research, thereby enhancing patient care. Emphasizing bespoke interventions and research could herald transformative shifts in therapeutic modalities.

Individual and joint effect of socioeconomic status and lifestyle factors on cancer in Korea

BACKGROUND

There is limited evidence on the individual and joint effect of socioeconomic status (SES) and unhealthy lifestyle on cancer. Therefore, this study aimed to examine the effects of these factors on cancer incidence and mortality.

METHODS

In this population-based cohort study, income was used as the proxy of SES. A combined unhealthy lifestyle score was obtained using data on smoking, alcohol consumption, physical activity, and body mass index. Hazard ratios were estimated using a Cox proportional hazards model.

RESULTS

The study included data on 8,353,169 participants (median follow-up period, 17 years). Although the association between low income and cancer incidence varied depending on cancer type, low income consistently increased the risk of cancer-related death with a social gradient. Unhealthy behaviors increased the risk of cancer incidence and mortality, except for thyroid and breast cancer in women and prostate cancer in men. Compared with the wealthiest and healthiest individuals, the poorest and unhealthiest men and women showed 2.1-fold (2.05-2.14) and 1.36-fold (1.31-1.41) higher risk of cancer-related death, respectively. The joint effect was most robust for lung, liver, head, and neck cancers in men and liver and cervical cancers in women; further, the effect was stronger with cancer-specific mortality than with incidence.

CONCLUSION

In conclusion, income and combined healthy lifestyle behaviors have individual and joint effects on cancer incidence and mortality. The effect varies by cancer type and sex.