Nationwide Population-based Cohort Study Research Articles

Mortality Risks and Causes in Previous Carbon Monoxide Poisoning: A Nationwide Population-Based Cohort Study

Objectives: Carbon monoxide (CO) poisoning can cause brain, heart, and kidney injuries. We aimed to determine the association of risks of all-cause and cause-specific mortality in patients with previous CO poisoning. Design, Setting, and Patients: This population-based cohort study used data from the National Health Insurance Service database and the National Death Registry of Korea. Adult patients diagnosed with CO poisoning and controls between 2002 and 2020 were included. Patients were matched with controls on a 1:1 ratio, considering age, sex, insurance type, income level, residential location, smoking status, alcohol consumption, obesity status, medical and psychiatric illness history, and Charlson Comorbidity Index at the index date. The cohort was monitored from 2002 to 2022 or until death or emigration in terms of all-cause and cause-specific mortality. Interventions: None. Measurements and Main Results: A total of 48,600 patients with CO poisoning and matched controls were included. The cohort included 41.30% females, and the mean age was 48.05 years. Patients with CO poisoning exhibited a substantially elevated risk of all-cause mortality compared with those in the control group, with an adjusted hazard ratio (aHR) of 15.67 (95% CI, 12.58–19.51). The mortality associated with infectious (aHR, 6.71; 95% CI, 1.51–29.72), neoplasm/oncologic (aHR, 5.20; 95% CI, 3.39–7.99), endocrine (aHR, 13.44; 95% CI, 1.76–102.70), neurologic (aHR, 7.42; 95% CI, 2.91–18.90), cardiovascular (aHR, 8.97; 95% CI, 5.05–15.93), respiratory (aHR, 17.54; 95% CI, 5.48–56.17), and gastrointestinal (aHR, 24.72; 95% CI, 3.34–182.69) disorders was significantly greater in the former. Deaths due to external causes, including suicide, were significantly higher in the CO poisoning group (aHR, 50.07; 95% CI, 30.98–80.90). Conclusions: Patients with CO poisoning exhibited a heightened risk of all-cause mortality compared with the matched controls. Additionally, the cause-specific mortality risk differed between the groups.

Risk of Traumatic Intracranial Hemorrhage After Stroke: A Nationwide Population-Based Cohort Study in Taiwan.

Stroke and traumatic intracranial hemorrhage (tICH) are major causes of disability worldwide, with stroke exerting significant negative effects on the brain, potentially elevating tICH risk. In this study, we investigated tICH risk in stroke survivors. Using relevant data (2017-2019) from Taiwan's National Health Insurance Research Database, we conducted a population-based retrospective cohort study. Patients were categorized into stroke and nonstroke groups, and tICH risk was compared using a Cox proportional-hazards model. Among 164 628 patients with stroke, 1004 experienced tICH. Patients with stroke had a higher tICH risk than nonstroke counterparts (adjusted hazard ratio [HR], 3.49 [95% CI, 3.17-3.84]). Subgroup analysis by stroke type revealed higher tICH risk in hemorrhagic stroke survivors compared with ischemic stroke survivors (HR, 5.64 [95% CI, 4.97-6.39] versus 2.87 [95% CI, 2.58-3.18], respectively). Older patients (≥45 years) with stroke had a higher tICH risk compared with their younger counterparts (<45 years), in contrast to younger patients without stroke (HR, 7.89 [95% CI, 6.41-9.70] versus 4.44 [95% CI, 2.99-6.59], respectively). Dementia and Parkinson disease emerged as significant tICH risk factors (HR, 1.69 [95% CI, 1.44-2.00] versus 2.17 [95% CI, 1.71-2.75], respectively). In the stroke group, the highest tICH incidence density occurred 3 months after stroke, particularly in patients aged >65 years. Stroke survivors, particularly those with hemorrhagic stroke and those aged ≥45 years, face elevated tICH risk. Interventions targeting the high-risk period are vital, with fall injuries potentially contributing to tICH incidence.

Congenital hypothyroidism and risk of subsequent autism spectrum disorder and attention-deficit/hyperactivity disorder in Taiwan.

Evidence suggests an association between maternal hypothyroidism and risk of attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) in offspring. We examined the risk of ASD and ADHD in individuals with congenital hypothyroidism (CHT). A nationwide population-based cohort study enrolled a total of 1260 children younger than 12 years with a confirmed diagnosis of CHT and no prior diagnosis of any neurodevelopmental disorders, selected from the National Health Insurance Research Database of Taiwan between 1998 to 2013. In addition, 12,600 controls matched for sex, age, and residence were selected. Cox proportional hazards analysis was used to investigate the association among CHT, ASD, and ADHD. Children with CHT were associated with a higher incidence of ASD (7.1‰ vs 1.3‰, P < 0.001) and ADHD (39.7‰ vs 18.7‰, P < 0.001) than the control group. Cox regression analyses demonstrated that children with CHT were associated with elevated risks of ASD (hazard ratio [HR], 4.72 [95% confidence interval (CI), 2.08-10.70]) and ADHD (HR, 2.03 [95% CI, 1.49-2.77]), after adjusting for demographic data and family history of major psychiatric disorders, compared with the control group. Children with CHT were associated with approximately a two-fold increased risk of ADHD and a four-fold increased risk of ASD than the control group. Our study highlights the need for future research to elucidate the potential pathophysiology among CHD, ASD, and ADHD.

Risk of psychiatric neurodevelopmental disorders after meningitis in childhood: a nationwide, population-based cohort study.

Few studies have investigated the risk of psychiatric neurodevelopmental disorders (PNDD) after childhood meningitis. Nationwide population-based cohort study (Denmark, 1995-2021) of children with positive cerebrospinal fluid for bacteria or enterovirus, stratified on age as young infants (0 to <90 days, n = 637) or older children (≥90 days to <17 years, n = 1,218). We constructed a comparison cohort from the general population (n = 18,550), and cohorts of siblings of participants. As risk estimates of PNDD we calculated age- and sex-adjusted hazard ratios (aHRs) with 95% confidence intervals (95%CI). Children with bacterial meningitis had increased risks of PNDD, especially learning and intellectual developmental disorders (young infants: aHR 4.2, 95%CI: 2.4-7.1; older children: aHR 1.5, 95%CI: 1.0-2.3), attention deficit disorder (ADHD) (young infants: aHR 2.8, 95%CI: 1.5-5.2; older children: 1.4, 95%CI: 0.9-2.2) and redemption of ADHD medication (young infants: aHR 2.2, 95%CI: 1.0-4.7; older children: 1.5, 95%CI: 1.0-2.3). Young infants with bacterial meningitis additionally had increased risks of autism spectrum disorders (aHR 1.9, 95%CI: 0.9-4.1) and behavioural and emotional disorders (aHR 2.0, 95%CI: 1.0-3.9). In young infants, the excess risk of PNDD was especially observed in premature children. Siblings of older children with bacterial meningitis also had increased risks of PNDD. Children with enteroviral meningitis at any age did not have increased risks of PNDD or redemption of ADHD medication. Bacterial meningitis in childhood is associated with subsequent diagnosis of PNDD, while enteroviral meningitis is not. The association appears to be partly explained by prematurity and familial and socioeconomic factors.

Retinal Vascular Occlusions After COVID-19 Vaccination in South Korea: A Nation-Wide Population-Based Study

ABSTRACT Purpose To investigate the association between the retinal vascular occlusion and vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods This nationwide population-based cohort study included 2,742,065 individuals aged ≥ 20 years who were vaccinated against SARS-CoV-2 from March 1, 2021, to December 31, 2021, and unvaccinated individuals matched at a ratio of approximately 1:10 by gender and age, all without a history of retinal vascular occlusion. The occurrence of retinal vascular occlusion was observed up to 60 days after the 1st vaccination date in the vaccination group, while 60 days from January 1, 2021, in the non-vaccination group. The risk of developing retinal vascular occlusion was compared between vaccinated and unvaccinated subjects. Risks were also compared among the different types of vaccines. Results Vaccination lowered the risk of retinal vascular occlusion, with an odds ratio (OR) of 0.80 (95% confidence interval (CI), 0.64–0.99; p = 0.039). For individuals aged < 40 years, the vaccination lowered the risk of retinal vascular occlusion occurrence significantly compared with those over the age of 40 (OR, 0.35 for age 20–39, 0.83 for age 40–64, 0.81 for age ≥ 65; P for interaction = 0.028). There was a significant difference in the ORs for retinal vascular occlusion among the four vaccine types (p < 0.001). Conclusions SARS-CoV-2 vaccination did not increase the risk of retinal vascular occlusion. However, the risk levels differed depending on the type of vaccine used. Considering the ongoing evolution of SARS-CoV-2 vaccines, it is imperative to conduct additional assessments of the recently introduced vaccines

Comment on: Surgeon age in relation to patients' long-term survival after gastrectomy for gastric adenocarcinoma: nationwide population-based cohort study.

Comment on: Surgeon age in relation to patients' long-term survival after gastrectomy for gastric adenocarcinoma: nationwide population-based cohort study.

Impact of multiple infections on risk of incident dementia according to subjective cognitive decline status: a nationwide population-based cohort study.

The interrelation between infections, subjective cognitive decline (SCD), and dementia development is recognized, but not fully understood. This study explored the combined effect of specific infections and SCD on the risk of dementia. To assess the influence of Helicobacter pylori, herpes simplex virus, varicella-zoster virus, and human papillomavirus on dementia risk in individuals with varying cognitive statuses, especially focusing on those with and without SCD. A cohort of 1,100,540 participants aged 66 years from the Korean National Health Insurance Service was divided into cognitively preserved (CP, n = 825,405) and SCD (n = 275,135) groups. This study analyzed the effects of single, dual, and triple infections on the risk of overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD) using incidence rates and hazard ratios. The SCD group consistently showed a doubled risk of dementia, particularly AD, regardless of the number of infections. In the initial data, both the presence and number of infections, especially in the CP group, were associated with an increased dementia incidence and risk; however, this correlation disappeared after adjusting for covariates, hinting at a possible protective effect. Our findings emphasize that, while SCD is a steadfast risk factor for dementia, the role of infections is layered, subject to various influences, and requires more comprehensive exploration to fully understand their impact on dementia development.

Obstetric anal sphincter injury in the second birth after perineal wound complication in the first birth: A nationwide register cohort study.

To investigate whether perineal wound complications in the first birth, alone or in conjunction with obstetric anal sphincter injury (OASI), is associated with an increased risk of OASI in the second birth. Nationwide population-based cohort study. Sweden. Women (n = 411 317) with first and second singleton vaginal births in Sweden, 2001-2019. Data on diagnostic codes and surgical procedures were retrieved from the Swedish Medical Birth Register and the Swedish Patient Register. A perineal wound complication was defined as wound infection, dehiscence or perineal haematoma within 2 months of childbirth. Associations between wound complications in the first birth and OASI in the second birth were investigated with logistic regression and presented as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs). In total, 2619 (0.6%) women had a wound complication in the first birth, and 5318 (1.3%) had an OASI in the second birth. Women with a wound complication but no OASI in the first birth had more than doubled odds of OASI in the second birth (aOR 2.73, 95% CI 2.11-3.53). Women with OASI and a wound complication in the first birth had almost tenfold odds (aOR 9.97, 95% CI 6.53-15.24) of recurrent OASI. Perineal wound complication in the first birth increases the likelihood of OASI in a subsequent birth.

Acarbose might be associated with reduced risk of gastric cancer in patients with diabetes mellitus: A nationwide population-based cohort study.

Several epidemiologic studies have revealed a higher risk of cancer in patients with diabetes mellitus (DM) relative to the general population. To investigate whether the use of acarbose was associated with higher/lower risk of new-onset cancers. We conducted a retrospective cohort study, using a population-based National Health Insurance Research Database of Taiwan. Both inpatients and outpatients with newly onset DM diagnosed between 2000 and 2012 were collected. The Adapted Diabetes Complications Severity Index (aDCSI) was used to adjust the severity of DM. The Cox proportional hazards regression model was used to estimate the hazard ratio (HR) of disease. A total of 22 502 patients with newly diagnosed DM were enrolled. The Cox proportional hazards regression model indicating acarbose was neutral for risk for gastroenterological malignancies, when compared to the acarbose non-acarbose users group. However, when gastric cancer was focused, acarbose-user group had significantly lowered HR than non-acarbose users group (p = 0.003). After adjusted for age, sex, cancer-related comorbidity, severity of DM, and co-administered drugs, the HR of gastric cancer risk was 0.43 (95% CI = 0.25-0.74) for acarbose-user patients. This long-term population-based study demonstrated that acarbose might be associated with lowered risk of new-onset gastric cancer in diabetic patients after adjusting the severity of DM.

50835 Air Quality Index (AQI) and atopic dermatitis risk in Taiwan: A nationwide population-based cohort study

50835 Air Quality Index (AQI) and atopic dermatitis risk in Taiwan: A nationwide population-based cohort study

Different Metabolic Associations of Hepatitis C With Colon and Rectal Cancers: A 9-Year Nationwide Population-Based Cohort Study

BackgroundWhether HCV infection is associated with colorectal cancer (CRC) development remains inconclusive. MethodsA nationwide population-based cohort study of the Taiwan National Health Insurance Research Database was conducted. ResultsFrom 2003 to 2012, 1:2:2 propensity score-matched HCV-treated [interferon-based therapy ≥ 6 months, surveys for CRC (n = 9017), colon cancer (CC) (n = 9,022) and rectal cancer (RC) (n = 9,033), HCV-untreated and HCV-uninfected cohorts CRC (n = 18034), CC (n = 18,044) and RC (n = 18,066) were enrolled. The HCV-uninfected cohort had the lowest cumulative incidence of CRC (0.117%; 95% CI: 0.062%-0.207%), whereas the HCV-treated (0.966%; 0.375-2.122%) and HCV-untreated (0.807%; 0.485%-1.280%) cohorts had similar incidences (P = .0662); HCV infection [reference: HCV-untreated cohort, HCV-treated: hazard ratio (HR): 0.598; 95% CI HR: 0.337-1.059; HCV-uninfected: 0.250; 0.138-0.456] and age ≥ 49 years (3.128;1.751-5.59) were associated with CRC development. The HCV-untreated cohort had the highest cumulative incidence of CC (0.883%; 0.371-1.839%), while HCV-treated (0.478%; 0.110-1.518%) and HCV-uninfected cohorts (0.147%; 0.071-0.284%) had similar incidences (P = .4853); HCV infection (HCV-treated: 0.474; 0.232-0.971; HCV-uninfected: 0.338; 0.184-0.62), male sex (2.18; 1.301-3.654), age≥ 49 years (4.818; 2.123-10.936) and diabetes (1.983; 1.205-3.262) were associated with CC development. A higher RC cumulative incidence was noted in the HCV-untreated cohort (0.332%; 0.151-0.664%) than in the HCV-uninfected cohort (0.116%; 0.054-0.232%) (P = .0352); HCV infection (HCV-treated: 0.691; 0.295-1.617; HCV-uninfected: 0.424; 0.207-0.867), age ≥ 49 years (3.745, 1.576-8.898) and stroke (3.162; 1.366-7.322) were associated with RC development. ConclusionsThe baseline associations were HCV infection and age ≥ 49 years with CRC; male sex and diabetes with CC; and stroke with RC. Anti-HCV therapy might reverse the risk of HCV-related CC but not RC.

Relationship between smoking experience and risk of suicide mortality in South Korean adults: A nationwide population-based retrospective cohort study

BackgroundKorea has one of the highest suicide rates in the world. Many factors associated with suicidal thoughts or behaviors are known. This study examines the association between 1) smoking status or intensity (pack-years) and 2) risk of suicide mortality in South Korea. MethodsWe analyzed data from 3,966,305 individuals aged ≥20 who underwent health examinations conducted by the South Korean National Health Insurance Service in 2009 and were followed until December 2021. Participants were categorized based on their baseline smoking status and intensity. We performed a Multivariate Cox proportional hazards regression analysis with subgroup analysis by age, sex, body mass index, alcohol consumption, regular exercise, and depression. ResultsDuring an 11.1-year follow-up period, 12,326 individuals died by suicide. Compared with never-smokers, increased hazard ratios of suicide mortality were observed in current smokers (1.64, 95 % CI = 1.56–1.72), but not in ex-smokers. The suicide mortality risk of current smokers increased for all types of smoking intensity without a dose–response relationship. The association between smoking and suicide mortality risk was stronger among women, non-drinkers, adults aged <40 years, non-obese patients, and individuals without depression. LimitationGiven that the study used retrospective data, the causal relationship remains unclear. ConclusionCurrent smoking is associated with a significant increased risk of suicide mortality. Smoking cessation is crucial to prevent suicide, especially among young adults, non-obese individuals, non-drinkers, women, and those without depression. Government policies in South Korea should focus on raising awareness about smoking hazards and providing cessation education to reduce the suicide mortality.

Non-cancer-related Deaths in Cancer Survivors: A Nationwide Population-Based Study in Japan.

Advancements in cancer care have improved survivorship, potentially leading to changes in mortality causes. This study aimed to investigate the causes of death among cancer survivors, specially focusing on non-cancer-related mortality. This nationwide population-based cohort study analyzed the causes of death based on the time since cancer diagnosis using data from the National Cancer Registry in Japan between January 2016 and December 2019. Non-cancer-related deaths were identified, and mortality risks associated with non-cancer diseases were compared to those of the Japanese general population using standardized mortality ratios (SMRs) with 95% confidence intervals (CIs). Follow-up period was up to 4 years after cancer diagnosis. A total of 3,990,661 patients (45.8%, women) were included in the analysis, yielding 6,237,269 person-years of follow-up. Of these, 1,001,857 (25.1%) patients died during the study period. Cancer-related and non-cancer-related causes accounted for 86.6% and 13.4% of deaths, respectively. The proportion of non-cancer-related deaths increased from 10.2% at 6 months to 31.6% at 4 years after cancer diagnosis. Heart disease (21.8%), cerebrovascular disease (9.8%), and pneumonia (9.1%) were the leading cause of non-cancer-related deaths: The SMRs for these diseases were 2.69 (95% CI, 2.66-2.72), 2.07 (95% CI, 2.03-2.10), and 2.41 (95% CI, 2.36-2.45), respectively. The SMR for suicide was 1.81 (95% CI, 1.74-1.89); however, it lost significance in males and females 2 and 2.5 years after cancer diagnosis, respectively. The proportion of non-cancer-related deaths among cancer patients has increased over time, emphasizing the need to manage cancer and its comorbidities carefully.

Polycystic ovary syndrome and risk of breast cancer in premenopausal and postmenopausal women: a nationwide population-based cohort study.

Although some reproductive and metabolic characteristics of polycystic ovary syndrome (PCOS) are known risk factors for breast cancer, the evidence regarding a potential association between PCOS and breast cancer is scarce. In this population-based cohort study including all 1,719,452 women born in Denmark between 1940 and 1993, we investigated the association between PCOS and breast cancer. PCOS diagnoses, cancer diagnoses, covariates, migrations, and vital status were all obtained from national population and health registers. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer overall and for histological subtypes separately were calculated based on adjusted cox proportional hazards models. During a median follow-up of 26years, 63,078 women were diagnosed with breast cancer. We found an increased risk of breast cancer overall among women with PCOS compared with women without PCOS (HR: 1.21, 95% CI 1.02-1.44). In analyses stratified for menopausal status, the increased risk was restricted to postmenopausal women (HR: 1.63, 95% CI 1.23-2.15). The results for ductal and lobular histological subtypes analyses separately resembled those observed for breast cancer overall. This is the first study to report an increased risk of breast cancer among women with a history of PCOS. The increased risk was seemingly confined to postmenopausal women. Our results therefore contribute to an increased knowledge of the etiology of breast cancer, but our findings should be further confirmed in other large cohort studies with an appropriately long follow-up period.

Long-term exposure to air pollution and the risks of venous thromboembolism: a nationwide population-based retrospective cohort study.

To delineate the effects of exposure to air pollution on the risk of venous thromboembolism (VTE). The association between air pollution and arterial occlusive diseases has been well reported in the literature. VTE is the third most common acute cardiovascular syndrome; however, its relationship with exposure to air pollution has been controversial. This study linked data from the Taiwan National Health Insurance Research Database with that from the Taiwan Environmental Protection Administration. Patients who were first admitted for VTE between January 1, 2001, and December 31, 2013, were analyzed. A time-stratified, case-crossover design was employed. Three different exposure periods were defined: exposure for 1month, one quarter, and 1year. Four control periods were designated for each exposure period. The association between exposure to air pollutants and the risk of VTE was tested using logistic regression analysis. Subgroup analyses were also performed, stratified by age, sex, type of VTE, the use of hormone therapy, and level of urbanization at the site of residence. Exposures to particulate matter (PM) smaller than 2.5µm (PM2.5) and those smaller than 10µm (PM10) were associated with higher risks of VTE, with longer exposures associated with higher risk. The concentration of PM2.5 exposure for 1month was linearly associated with a greater risk of VTE up to 28.0µg/m3, beyond which there was no association. PM2.5 exposure for one quarter or 1year remained significantly associated with higher risks of VTE at higher concentrations. The increased risk in VTE associated with exposure to PM2.5 was more prominent in older patients and in patients not under hormone therapy. Similar results were observed for PM10 exposures. Exposure to PM, particularly PM2.5, leads to an increased risk of VTE, with possible accumulative effects. With increased PM production in industrializing countries, the effects of PM on VTE occurrence warrant further attention.

Association of Uterine Leiomyoma with Type 2 Diabetes Mellitus in Young Women: A Population-Based Cohort Study.

We investigated the association between uterine leiomyoma (UL) and incident type 2 diabetes mellitus (T2DM) in young women. A nationwide population-based cohort study of 2,541,550 women aged between 20 and 40 years was performed using the National Health Information Database. Cox proportional hazards models were used to analyze the risk of incident T2DM according to the presence of UL and myomectomy. The mean age was 29.70 years, and mean body mass index was 21.31 kg/m2. Among 2,541,550 participants, 18,375 (0.72%) women had UL. During a median 7.45 years of follow-up, 23,829 women (0.94%) were diagnosed with T2DM. The incidence of T2DM in women with UL (1.805/1,000 person-years) was higher than in those without UL (1.289/1,000 person-years). Compared with women without UL, women with UL had a higher risk of incident T2DM (hazard ratio, 1.216; 95% confidence interval [CI], 1.071 to 1.382). Women with UL who did not undergo myomectomy had a 1.505 times (95% CI, 1.297 to 1.748) higher risk for incident T2DM than women without UL. However, women with UL who underwent myomectomy did not have increased risk for incident T2DM. Young women with UL were associated with a high risk of incident T2DM. In addition, myomectomy seemed to attenuate the risk for incident T2DM in young women with UL.

Prevalence, Risk Factors, and Postoperative Infection Rates of Blood Transfusion in Lumbar Spinal Fusion Surgery: A Nationwide Population-Based Study.

Study Design: Retrospective cohort study. Objectives: Effects of blood loss that requires blood transfusion after lumbar spinal fusion remain an important issue. Blood transfusions are used commonly in cases of significant blood loss in lumbar spinal fusion but are associated with adverse effects. The objective was to assess the rate of blood transfusion and the associated risk after lumbar spinal fusion from 2013 to 2018. Methods: In this nationwide population-based cohort study, the Korean Health Insurance Review and Assessment Service database was reviewed retrospectively from 2013 to 2018. Data were extracted from patients who underwent lumbar spinal fusion without history of lumbar spinal surgery in the preceding year. The primary outcome was the rate of blood transfusion within 1 week of surgery. In addition, the risk factors for blood transfusion and the rate of postoperative infection were evaluated. Results: A total of 188,581 patients underwent lumbar spinal fusion between 2013 and 2018. A significant decline in blood transfusions was observed during the study period (56.38-47.51%). The presence of comorbidities was associated with an increased risk of blood transfusion. Patients who underwent the posterior approach were more likely to receive blood transfusion than patients who underwent the anterior or anterior and posterior approach. Receiving blood transfusion was associated with postoperative infection. Conclusions: In the present study, the prevalence, risk factors, and postoperative infection rates associated with blood transfusion in lumbar spinal fusion were identified. Spine surgeons should consider these risk factors in patients at high risk of blood transfusion.

Insurance Types and All-Cause Mortality in Korean Cancer Patients: A Nationwide Population-Based Cohort Study.

Economic deprivation is expected to influence cancer mortality due to its impact on screening and treatment options, as well as healthy lifestyle. However, the relationship between insurance type, premiums, and mortality rates remains unclear. This study investigated the relationship between insurance type and mortality in patients with newly diagnosed cancer using data from the Korean National Health Insurance Database. this retrospective cohort study included 111,941 cancer patients diagnosed between 1 January 2007 and 31 December 2008, with a median follow-up period of 13.41 years. The insurance types were categorized as regional and workplace subscribers and income-based insurance premiums were divided into tertiles (T1, T2, and T3). Cox proportional hazards regression analysis adjusted for age, lifestyle factors, health metrics, and comorbidities showed workplace subscribers (n = 76,944) had a lower all-cause mortality hazard ratio (HR) (95% confidence interval [CI]: 0.940 [0.919-0.961]) compared to regional subscribers (n = 34,997). Higher income tertiles (T2, T3) were associated with lower mortality compared to the T1 group, notably in male regional and workplace subscribers, and female regional subscribers. The study identified that insurance types and premiums significantly influence mortality in cancer patients, highlighting the necessity for individualized insurance policies for cancer patients.

Impact of Helicobacter pylori eradication on age-specific risk of incident dementia in patients with peptic ulcer disease: a nationwide population-based cohort study.

The impact of peptic ulcer disease (PUD) and Helicobacter pylori (H. pylori) eradication therapy on dementia risk in high H. pylori prevalence populations remains uncertain. This study investigates the relationship between PUD, H. pylori eradication, and dementia risk, including Alzheimer's disease (AD), in an elderly South Korean cohort, considering age and eradication timing. Data from the Korean National Health Insurance Service (2002-2015) for individuals aged 55-79 were analyzed. Participants were divided based on PUD and H. pylori therapy status. Propensity score matching was used to evaluate dementia incidence and hazard ratios over 5 and 10 years, alongside the timing of eradication therapy. PUD is linked to higher dementia risk at 5 and 10 years, more for overall dementia than AD, with eradication status not significantly altering the risk. Age-specific analysis showed increased AD risk in the 60s and 70s age groups. Late eradication therapy is correlated with a higher dementia risk. PUD is a risk factor for dementia in elderly South Koreans, particularly with delayed H. pylori therapy. The findings emphasize timely H. pylori management and its potential role in neurodegenerative disease prevention.

Association between gastrectomy and the risk of type 2 diabetes in gastric cancer survivors: A nationwide cohort study

AimPostprandial glycemic fluctuations after gastrectomy are seen in patients with gastric cancer but, no studies have investigated the association between gastrectomy and type 2 diabetes mellitus (T2DM) in gastric cancer survivors. This study aimed to elucidate the relationship between gastrectomy (total or subtotal) and incident T2DM. In addition, we explored whether vitamin B12 supplementation modulates this risk among patients who have undergone total gastrectomy. MethodsIn this large nationwide population-based retrospective cohort study using the National Health Insurance Service database of South Korea, we identified patients aged >20 years who underwent gastrectomy from 2008 to 2015 (n = 150,074) and age- and sex-matched controls without gastrectomy (n = 301,508). A Cox proportional hazards model was used. ResultsDuring the median follow-up duration of 4.4 years after the 2-year time lag after gastrectomy, of the 78,006 subjects, 4,597 (5.9 %) developed T2DM. Compared with matched controls, the adjusted hazard ratio (AHR[95 % confidence interval]) for T2DM of patients with total gastrectomy was 1.34[1.23;1.47]. The corresponding AHR after subtotal gastrectomy was 0.81[0.76;0.86]. Among the patients with total gastrectomy, the risk of T2DM was significantly increased in those who did not receive any vitamin B12 supplementation (AHR=1.60[1.33;1.92]), whereas the risk of T2DM was lower (close to being statistically significant) in those who received continuous vitamin B12 supplementation after gastrectomy (AHR=0.70[0.49;1.01]). ConclusionThese results show a significantly reduced risk of T2DM in gastric cancer patients undergoing subtotal gastrectomy and a significantly increased risk of T2DM in gastric cancer patients undergoing total gastrectomy, which is mitigated by continuous vitamin B12 supplementation.