Population-based Matched Cohort Study Research Articles

Exploring the association between acute pancreatitis and biliary tract cancer: A large-scale population-based matched cohort study.

Biliary tract cancer (BTC) often goes undetected until its advanced stages, resulting in a poor prognosis. Given the anatomical closeness of the gallbladder and bile ducts to the pancreas, the inflammatory processes triggered by acute pancreatitis might increase the risk of BTC. To assess the association between acute pancreatitis and the risk of BTC. Using the Swedish Pancreatitis Cohort (SwePan), we compared the BTC risk in patients with a first-time episode of acute pancreatitis during 1990-2018 to a 1:10 matched pancreatitis-free control group. Multivariable Cox regression models, stratified by follow-up duration, were used to calculate hazard ratios (HRs), adjusting for socioeconomic factors, alcohol use, and comorbidities. BTC developed in 0.94% of 85,027 acute pancreatitis patients and in 0.23% of 814,993 controls. The BTC risk notably increased within 3months of hospital discharge (HR 82.63; 95% CI: 63.07-108.26) and remained elevated beyond 10years of follow-up (HR 1.82; 95% CI: 1.35-2.47). However, the long-term risk of BTC subtypes did not increase with anatomical proximity to the pancreas, with a null association for gallbladder and extrahepatic tumors. Importantly, patients with acute pancreatitis had a higher occurrence of early-stage BTC within 2years of hospital discharge than controls (13.0 vs. 3.6%; p-value <0.01). Our nationwide study found an elevated BTC risk in acute pancreatitis patients; however, the risk estimates for BTC subtypes were inconsistent, thereby questioning the causality of the association. Importantly, the amplified detection of early-stage BTC within 2years after a diagnosis of acute pancreatitis underscores the necessity for proactive BTC surveillance in these patients.

Increased bronchiectasis risk and related risk factors in inflammatory bowel disease: A 10-year Korean national cohort study

BackgroundThe association between inflammatory bowel disease (IBD) and an increased risk of bronchiectasis, as well as contributing factors, remains unclear. Additionally, whether bronchiectasis increases disease burden in IBD remains unknown. Therefore, this study aimed to 1) assess whether IBD increases the risk of incident bronchiectasis; 2) compare the risk of bronchiectasis between individuals with Crohn's disease (CD) and those with ulcerative colitis (UC); 3) identify risk factors for bronchiectasis in individuals with IBD; and 4) examine the disease burden in individuals with IBD and bronchiectasisversusthose without.MethodsWe conducted a population-based matched cohort study involving adults aged ≥20 years with IBD, using data acquired from the National Health Insurance Service-National Sample Cohort database in Korea between 2002 and 2012.ResultsDuring the mean follow-up of 9.6 years, the incidence rate of bronchiectasis was 419.63/100 000 and 309.65/100 000 person-years (PY) in the IBD and matched cohorts (adjusted hazard ratio [aHR]=1.21, 95% confidence interval [CI]=1.05–1.39), respectively. UC was associated with increased bronchiectasis risk (aHR=1.42, 95% CI=1.19–1.69), while CD was not. Multivariate Cox regression analyses showed that age, male sex, medical aid, underweight status, chronic obstructive pulmonary disease, and diabetes mellitus were associated with an increased risk of bronchiectasis in the IBD cohort (p&lt;0.05). The mortality, emergency department visit, and hospitalisation rates were significantly higher for individuals with IBD and bronchiectasis compared to those without bronchiectasis (p&lt;0.05).ConclusionIBD is associated with increased risk of bronchiectasis, which results in a greater disease burden in individuals with IBD.

Association of diverticulitis and potential risk of ischemic stroke: population-based matched cohort study in Taiwan.

Previous studies have suggested relationship between diverticular disease and cardiovascular disease. Since cardiovascular disease and cerebrovascular accident share a lot of pathogenesis, diverticulitis could also be a risk factor for stroke. This study tried to establish epidemiological evidence of the relationship between colon diverticulitis and ischemic stroke. In this retrospective cohort study, patients with newly diagnosed colon diverticulitis (N = 6238) and patients without colon diverticulitis (control group; N = 24 952) were recruited between January 1, 2000, and December 31, 2017. Both groups were matched by propensity score at a 1:4 ratio by age, sex, comorbidities and medications. Cox proportional hazard regression was applied to estimate the hazard ratio (HR) and 95% confidence interval (CI) of ischemic stroke. We also conducted 4 different regression models and 2 sensitivity analyses to test the robustness of our findings. The diverticulitis group had a higher risk of IS than the control group (adjusted HR, 1.25; 95% CI, 1.12-1.39; P < 0.001). Serial sensitivity analyses yielded consistent positive link between diverticulitis and IS. Further subgroup analysis showed that in the study group, the risk of IS was 2.54-fold higher than the matched controls in 30-39years. Our study found that colon diverticulitis was associated with a higher risk of developing subsequent ischemic stroke, especially for patients aged 30-39years, among Asian population. This result provides us a chance to undertake preventive measures for ischemic stroke in high-risk patients.

Comorbidities associated with adult asthma: a population-based matched cohort study in Finland

BackgroundAsthma is a common chronic disease characterised by variable respiratory symptoms and airflow limitation, affecting roughly 4%–10% of the adult population. Adult asthma is associated with higher all-cause mortality compared...

Microscopic Colitis and Risk of Incident Psoriasis: A Nationwide Population-Based Matched Cohort Study.

Microscopic colitis (MC) has been associated with several immune-mediated diseases including psoriasis, but earlier research has been limited to psoriasis occurring before MC. Data from large-scale cohort studies investigating MC and risk of future psoriasis are lacking. To examine the association between MC and psoriasis. In a nationwide, population-based, matched cohort study in Sweden from 2007 to 2021, we identified 8404 patients with biopsy-verified MC (diagnosed in 2007-2017), 37,033 matched reference individuals, and 8381 siblings without MC. Information on MC was obtained through the ESPRESSO cohort (a Swedish histopathology database with nationwide coverage). Using Cox regression, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for psoriasis up until 2021. During a median follow-up of 9.2 years (interquartile range = 6.7-11.7), 179 MC patients and 440 reference individuals were diagnosed with psoriasis (241.1 vs 131.8 events per 100,000 person-years), corresponding to one extra case of psoriasis in 91 patients with MC over 10 years. After adjustment for the matching variables (birth year, sex, county of residence, and calendar period) and level of education, we computed an adjusted hazard ratio (aHR) of 1.82 (95% CI = 1.53-2.17). Stratified by sex, estimates were similar and when examining the aHR across different lengths of follow-up, we found significantly elevated estimates up to 10 years after MC diagnosis. Compared to MC-free siblings, the aHR was 1.85 (95% CI = 1.36-2.51). Patients with MC are at an almost doubled risk of psoriasis compared to the general population. Clinicians need to consider psoriasis in MC patients with skin lesions.

Hepatitis C Attributable Healthcare Costs and Mortality among Immigrants: A Population-Based Matched Cohort Study.

Data on the economic burden of chronic hepatitis C (CHC) among immigrants are limited. Our objective was to estimate the CHC-attributable mortality and healthcare costs among immigrants in Ontario, Canada. We conducted a population-based matched cohort study among immigrants diagnosed with CHC between May 31, 2003, and December 31, 2018, using linked health administrative data. Immigrants with CHC (exposed) were matched 1 : 1 to immigrants without CHC (unexposed) using a combination of hard (index date, sex, and age) and propensity-score matching. Net costs (2020 Canadian dollars) collected from the healthcare payer perspective were calculated using a phase-of-care approach and used to estimate long-term costs adjusted for survival. We matched 5,575 exposed individuals with unexposed controls, achieving a balanced match. The mean age was 47 years, and 52% was male. On average, 10.5% of exposed and 3.5% of unexposed individuals died 15 years postindex (relative risk = 2.9; 95% confidence interval (CI): 2.6-3.5). The net 30-day costs per person were $88 (95% CI: 55 to 122) for the prediagnosis, $324 (95% CI: 291 to 356) for the initial phase, $1,016 (95% CI: 900 to 1,132) for the late phase, and $975 (95% CI: -25 to 1,974) for the terminal phase. The mean net healthcare cost adjusted for survival at 15 years was $90,448. Compared to unexposed immigrants, immigrants infected with CHC have higher mortality rates and greater healthcare costs. These findings will support the planning of HCV elimination efforts among key risk groups in the province.

Medication utilization in traumatic brain injury patients-insights from a population-based matched cohort study.

Traumatic brain injury (TBI) is associated with health problems across multiple domains and TBI patients are reported to have high rates of medication use. However, prior evidence is thin due to methodological limitations. Our aim was thus to examine the use of a wide spectrum of medications prescribed to address pain and somatic conditions in a population-based cohort of TBI patients, and to compare this to a sex- and age-matched cohort. We also examined how patient factors such as sex, age, and TBI severity were associated with medication use. We assessed Swedish nationwide registers to include all individuals treated for TBI in hospitals or specialist outpatient care between 2006 and 2012. We examined dispensed prescriptions for eight different non-psychotropic medication classes for the 12 months before, and 12 months after, the TBI. We applied a fixed-effects model to compare TBI patients with the matched population cohort. We also stratified TBI patients by sex, age, TBI severity and carried out comparisons using a generalized linear model. We identified 239,425 individuals with an incident TBI and 239,425 matched individuals. TBI patients were more likely to use any medication [Odds ratio (OR) = 2.03, 95% Confidence Interval (CI) = 2.00-2.05], to present with polypharmacy (OR = 1.96, 95% CI = 1.90-2.02), and to use each of the eight medication classes before their TBI, as compared to the matched population cohort. Following the TBI, TBI patients were more likely to use any medication (OR = 1.83, 95% CI = 1.80-1.86), to present with polypharmacy (OR = 1.74, 95% CI = 1.67-1.80), and to use all medication classes, although differences were attenuated. However, differences increased for antibiotics/antivirals (OR = 2.02, 95% CI = 1.99-2.05) and NSAIDs/antirheumatics (OR = 1.62, 95% CI = 1.59-1.65) post-TBI. We also found that females and older patients were more likely to use medications after their TBI than males and younger patients, respectively. Patients with more severe TBIs demonstrated increased use of antibiotics/ antivirals and NSAIDs/antirheumatics than those with less severe TBIs. Taken together, our results point to poor overall health in TBI patients, suggesting that medical follow-up should be routine, particularly in females with TBI, and include a review of medication use to address potential polypharmacy.

Risk of fractures in half a million survivors of 20 cancers: a population-based matched cohort study using linked English electronic health records

A history of multiple myeloma, prostate cancer, and breast cancer has been associated with adverse bone health, but associations across a broader range of cancers are unclear. We aimed to compare the risk of any bone fracture and major osteoporotic fractures in survivors of a wide range of cancers versus cancer-free individuals. In this population-based matched cohort study, we used electronic health records from the UK Clinical Practice Research Datalink linked to hospital data. We included adults (aged ≥18 years) eligible for linkage, and we restricted the study start to Jan 2, 1998, onwards and applied administrative censoring on Jan 31, 2020. The cancer survivor group included survivors of the 20 most common cancers. Each individual with cancer was matched (age, sex, and general practice) to up to five controls (1:5) who were cancer-free. The primary outcomes were any bone fracture and any major osteoporotic fracture (pelvic, hip, wrist, spine, or proximal humeral fractures) occurring more than 1 year after index date (ie, the diagnosis date of the matched individual with cancer). We used Cox regression models, adjusted for shared risk factors, to estimate associations between cancer survivorship and bone fractures. 578 160 adults with cancer diagnosed in 1998-2020 were matched to 3 226 404 cancer-free individuals. Crude incidence rates of fractures in cancer survivors ranged between 8·39 cases (95% CI 7·45-9·46) per 1000 person-years for thyroid cancer and 21·62 cases (20·18-23·18) per 1000 person-years for multiple myeloma. Compared with cancer-free individuals, the risk of any bone fracture was increased in 15 of 20 cancers, and of major osteoporotic fractures in 17 of 20 cancers. Effect sizes varied: adjusted hazard ratios (HRs) were largest for multiple myeloma (1·94, 95% CI 1·77-2·13) and prostate cancer (1·43, 1·39-1·47); HRs in the range 1·20-1·50 were seen for stomach, liver, pancreas, lung, breast, kidney, and CNS cancers; smaller associations (HR <1·20) were observed for malignant melanoma, non-Hodgkin lymphoma, leukaemia, and oesophageal, colorectal, and cervical cancers. Increased risks of major osteoporotic fracture were noted most substantially in multiple myeloma (2·25, 1·96-2·58) and CNS (2·12, 1·56-2·87), liver (1·62, 1·01-2·61), prostate (1·60, 1·53-1·67), and lung cancers (1·60, 1·44-1·77). Effect sizes tended to reduce over time since diagnosis but remained elevated for more than 5 years in several cancers, such as multiple myeloma and stomach, lung, breast, prostate, and CNS cancers. Survivors of most types of cancer were at increased risk of bone fracture for several years after cancer, with variation by cancer type. These findings can help to inform mitigation and prevention strategies. Wellcome Trust.

Risk of cardiac conduction disorders, and pacemaker implantations among individuals tested for serum Borrelia burgdorferi antibodies, a nationwide, matched, population-based cohort study

ObjectivesTo investigate the short- and long-term risks of atrioventricular block and other cardiac conduction disorders associated with being tested for Borrelia burgdorferi (Bb) antibodies or Bb seropositivity as measures of confounding by indication and Bb infection, respectively. MethodsWe performed a nationwide population-based matched cohort study (Denmark, 1993–2021). We included 52 200 Bb-seropositive individuals (stratified as only Bb-IgM-seropositive [n = 26 103], only Bb-IgG-seropositive [n = 18 698], and Bb-IgM-and-IgG-seropositive [n = 7399]) and two age- and sex-matched comparison cohorts: 104 400 Bb-seronegative individuals and 261 000 population controls. We investigated the risk associated with being tested for serum Bb antibodies and being Bb seropositive. Outcomes were atrioventricular block and other conduction disorders. We calculated short-term odds ratios (aOR) (within 1 month), and long-term hazard ratios (aHR) (after 1 month) adjusted for age, sex, diabetes, chronic heart failure, and kidney disease with 95% CI. ResultsCompared with population controls, individuals tested for Bb antibodies had increased short- and long-term risks of atrioventricular block (aOR 47.9, 95% CI: 30.0–76.7, aHR 1.3, 95% CI:1.2–1.3), and other conduction disorders (aOR 18.2, 95% CI: 10.1–32.8, aHR 1.2, 95% CI: 1.1–1.4). Compared with Bb-seronegative individuals, only Bb-IgM-and-IgG-seropositive individuals had increased short-term risk of atrioventricular block (aOR: 2.1, 95% CI: 1.5–3.1). DiscussionThe results suggest that Bb antibody testing is included in the diagnostic work-up of conduction disorders. Finally, that Bb seropositivity is not associated with other conduction disorders than atrioventricular block or with increased long-term risk of conduction disorders.

Herpes zoster diagnosis and treatment in relation to incident dementia: A population-based retrospective matched cohort study.

Evidence suggests that some infectious diseases, such as herpes zoster (HZ), are associated with elevated risk of subsequent dementia, while certain anti-viral medications are associated with lower risk. We sought to evaluate associations between HZ diagnosis and treatment with incident dementia in a large, retrospective matched cohort. Using ICD-9 and ICD-10 diagnosis codes in electronic medical records, we identified members of Kaiser Permanente Northwest age 50 and older from 2000-2019 with a HZ diagnosis during this period. A comparison group without HZ diagnosis was individually matched 3:1 on age at HZ diagnosis date (index date), sex, and membership length prior to index date. We excluded subjects with dementia diagnosed before the index date. Antiherpetic medication was identified using pharmacy fills 1 month before to 12 months after the index date. We employed survival analysis to examine the associations between dementia and HZ diagnosis and antiherpetic medication, adjusting multivariable models for demographic and clinical factors. We stratified on age and sex and conducted a sensitivity analysis with a 5-year lag period. The study included 101,328 persons, 25,332 with HZ. Over a median follow-up of 4.8 years, 6,000 developed dementia. HZ diagnosis was not associated with higher hazard of dementia (hazard ratio (HR) = 0.99, 95% CI 0.93-1.05) in the primary analysis. Among persons with HZ diagnoses, the HR for receipt of any antiherpetic medication was 0.79 (95% CI 0.70-0.90) in univariate analysis and 0.88 (95% CI 0.77-1.00) after adjustment for demographic and clinical factors. Dementia was not associated with trends in duration of medication use or cumulative dose. We found little evidence for an association between HZ diagnosis and dementia overall. Antiherpetic medication prescribed around the time of HZ diagnosis was statistically associated with lower risk of subsequent dementia in some but not all analyses and subgroups.

Bipolar disorder and the risk of cardiometabolic diseases, heart failure, and all-cause mortality: a population-based matched cohort study in South Korea

The association of bipolar disorder (BD) with the risk of cardiometabolic diseases and premature death in Asians needs to be further determined. Relatively less attention has been paid to heart failure (HF) among cardiometabolic outcomes. We analyzed the Korean National Health Insurance Service database (2002–2018) for this population-based, matched cohort study. The hazards of ischemic stroke, ischemic heart disease (IHD), hospitalization for HF (hHF), composite cardiometabolic diseases, and all-cause mortality during follow-up were compared between individuals with BD (n = 11,329) and 1:1-matched controls without psychiatric disorders among adults without cardiometabolic disease before or within 3 months of baseline. Hazards of outcomes were higher in individuals with BD than in matched controls (adjusted hazard ratios [95% confidence intervals]: 1.971 [1.414–2.746] for ischemic stroke, 1.553 [1.401–1.721] for IHD, 2.526 [1.788–3.567] for hHF, 1.939 [1.860–2.022] for composite cardiometabolic diseases, and 2.175 [1.875–2.523] for all-cause mortality) during follow-up. Associations between BD and outcome hazards were more prominent in younger individuals (p for interaction < 0.02, except for ischemic stroke) and women (p for interaction < 0.04, except for hHF). Screening and preventive measures for cardiometabolic deterioration and early mortality may need to be intensified in individuals with BD, even in young adults, especially women.

Abstract A009: Association between unstable diabetes mellitus and risk of pancreatic cancer

Abstract Worsening of hyperglycemia in people with pre-existing diabetes mellitus may be an indicator of undiagnosed pancreatic cancer. However, there is limited evidence from longitudinal studies regarding the association between deterioration of diabetes and pancreatic cancer in people with previously stable diabetes. The size of the association between deterioration of diabetes and pancreatic cancer, and how the association changes over time, needs further investigation. A population-based matched cohort study was conducted within Australian women with stable diabetes mellitus. Unstable diabetes, the exposure of interest, was defined as change in the type of antidiabetic medication or addition of another antidiabetic medication after at least 24 months of stable antidiabetic medication use. The date of exposure was defined as the index date. Each woman with unstable diabetes was matched to 4 women with stable diabetes by birth year (±1 year) at the index date. Flexible parametric survival models were used to estimate hazard ratios (HR) (overall and at different times) and 95% confidence intervals (CI), and absolute risk in both groups at different time points. We identified 134,954 women with unstable diabetes; these were matched to women who had not developed unstable diabetes at the index date. The mean age of the cohort was 68 years. Over a median follow-up period of 2.8 years, 1,315 pancreatic cancer cases were diagnosed. Overall, women who experienced deterioration in glycemic control had a 2.5-fold increased risk of developing pancreatic cancer (HR 2.55; 95% CI 2.29 – 2.85). The risk was very high during the initial few months [HRs at 3 months (5.76; 95% CI 4.72 – 7.04), 6 months (4.56; 95% CI 3.81 – 5.46), and 12 months (3.33; 95% CI 2.86 – 3.89)]. The risk then progressively declined with time. Worsening of glycemic control in those with previously stable diabetes may be an early clinical manifestation of pancreatic cancer. Further research is warranted to differentiate this pancreatic cancer-associated deterioration of glycemic control from other causes. The longer-term (3-7 years) weaker association between pancreatic cancer and deterioration of glycemic control suggests that poorly controlled hyperglycemia is a predisposing factor for pancreatic cancer. Citation Format: Sitwat Ali, Michael Coory, Peter Donovan, Renhua Na, Nirmala Pandeya, Sallie-Anne Pearson, Katrina Spilsbury, Louise Stewart, Bridie Thompson, Karen Tuesley, Mary Waterhouse, Penelope Webb, Susan Jordan, Rachel Neale. Association between unstable diabetes mellitus and risk of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A009.

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

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

Comparison of Acute Health Care Utilization Between Patients Receiving In-Center Hemodialysis and the General Population: A Population-Based Matched Cohort Study From Ontario, Canada.

Patients receiving maintenance hemodialysis have multiple comorbidities and are at high risk of presenting to the hospital. However, the incidence and cost of acute health care utilization in the in-center hemodialysis population and how this compares with other populations is poorly understood. To determine the rate, pattern, and cost of emergency department visits and hospitalizations in patients receiving in-center hemodialysis compared with a matched general population. Population-based matched cohort study. We used linked administrative health care databases from Ontario, Canada. We included 25 379 patients (incident and prevalent) receiving in-center hemodialysis between January 1, 2010, and December 31, 2018. Patients were matched on birth date (±2 years), sex, and cohort entry date using a 1:4 ratio to 101 516 individuals from the general population. Our primary outcomes were emergency department visits (allowing for multiple visits per individual) and hospital admissions from the emergency department. We also assessed all-cause hospitalizations, all-cause readmissions within 30 days of discharge from the original hospitalization, length of stay for hospital admissions (including multiple visits per individual), and the financial cost of these admissions. We presented the rate, percentage, median (25th, 75th percentiles), and incidence rate per 1000 person-years for emergency department visits and hospitalizations. Individual-level health care costs for emergency department visits and all-cause hospitalization were estimated using resource intensity weights multiplied by the cost per weighted case. Patients receiving in-center hemodialysis had substantially more comorbidities (eg, diabetes) than the matched general population. Eighty percent (n = 20 309) of patients receiving in-center hemodialysis had at least 1 emergency department visit compared with 56% (n = 56 452) of individuals in the matched general population, over a median follow-up of 1.8 years (25th, 75th percentiles: 0.7, 3.6) and 5.2 (2.5, 8.4) years, respectively. The incidence rate of emergency department visits, allowing for multiple visits per individual, was 2274 per 1000 person-years (95% confidence interval [CI]: 2263, 2286) for patients receiving in-center hemodialysis, which was almost 5 times as high as the matched general population (471 per 1000 person-years; 95% CI: 469, 473). The rate of hospital admissions from the emergency department and the rate of all-cause hospital admissions in the in-center hemodialysis population was more than 7 times as high as the matched general population (hospital admissions from the emergency department: 786 vs 101 per 1000 person-years; all-cause hospital admissions: 1056 vs 139 per 1000 person-years). The median number of all-cause hospitalization days per patient year was 4.0 (0, 16.5) in the in-center hemodialysis population compared with 0 (0, 0.5) in the matched general population. The cost per patient-year for emergency department visits in the in-center hemodialysis population was approximately 5.5 times as high as the matched general population while the cost of hospitalizations in the in-center hemodialysis population was approximately 11 times as high as the matched general population (emergency department visits: CAN$ 1153 vs CAN$ 209; hospitalizations: CAN$ 21 151 vs CAN$ 1873 [all costs in 2023 CAN$]). External generalizability and we could not determine whether emergency department visits and hospitalizations were preventable. Patients receiving in-center hemodialysis have high acute health care utilization. These results improve our understanding of the burden of disease and the associated costs in the in-center hemodialysis population, highlight the need to improve acute outcomes, and can aid health care capacity planning. Additional research is needed to address the risk of hospitalization after controlling for patient comorbidities. This is not applicable as this is a population-based matched cohort study and not a clinical trial.

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

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

Cardiovascular and mortality outcomes with GLP-1 receptor agonists vs other glucose-lowering drugs in individuals with NAFLD and type 2 diabetes: a large population-based matched cohort study.

We aimed to determine whether the use of glucagon-like peptide-1 receptor agonists (GLP-1RA) in individuals with non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus decreases the risk of new-onset adverse cardiovascular events (CVEs) and mortality rate compared with other glucose-lowering drugs in a real setting at a population level. We conducted a population-based propensity-matched retrospective cohort study using TriNetX. The cohort comprised patients over 20 years old who were newly treated with glucose-lowering drugs between 1 January 2013 and 31 December 2021, and followed until 30 September 2022. New users of GLP-1RAs were matched based on age, demographics, comorbidities and medication use by using 1:1 propensity matching with other glucose-lowering drugs. The primary outcome was the new onset of adverse CVEs, including heart failure, composite incidence of major adverse cardiovascular events (MACE; defined as unstable angina, myocardial infarction, or coronary artery procedures or surgeries) and composite cerebrovascular events (defined as the first occurrence of stroke, transient ischaemic attack, cerebral infarction, carotid intervention or surgery), and the secondary outcome was all-cause mortality. Cox proportional hazards models were used to estimate HRs. The study involved 2,835,398 patients with both NAFLD and type 2 diabetes. When compared with the sodium-glucose cotransporter 2 (SGLT2) inhibitors group, the GLP-1RAs group showed no evidence of a difference in terms of new-onset heart failure (HR 0.97; 95% CI 0.93, 1.01), MACE (HR 0.95; 95% CI 0.90, 1.01) and cerebrovascular events (HR 0.99; 95% CI 0.94, 1.03). Furthermore, the two groups had no evidence of a difference in mortality rate (HR 1.06; 95% CI 0.97, 1.15). Similar results were observed across sensitivity analyses. Compared with other second- or third-line glucose-lowering medications, the GLP-1RAs demonstrated a lower rate of adverse CVEs, including heart failure (HR 0.88; 95% CI 0.85, 0.92), MACE (HR 0.89; 95% CI 0.85, 0.94), cerebrovascular events (HR 0.93; 95% CI 0.89, 0.96) and all-cause mortality rate (HR 0.70; 95% CI 0.66, 0.75). In individuals with NAFLD and type 2 diabetes, GLP-1RAs are associated with lower incidences of adverse CVEs and all-cause mortality compared with metformin or other second- and third-line glucose-lowering medications. However, there was no significant difference in adverse CVEs or all-cause mortality when compared with those taking SGLT2 inhibitors.

Risk of tuberculosis after endoscopic resection and gastrectomy in gastric cancer: nationwide population-based matched cohort study.

This study aimed to investigate the association between gastrectomy and endoscopic resection for gastric cancer and the subsequent tuberculosis incidence. We conducted a nationwide matched cohort study using data from the Korea National Health Insurance Service from 2013 to 2019. We created two cohorts: patients who underwent gastrectomy and those who had endoscopic resection. Each patient was matched 1:1 with an unexposed individual based on index year, age, sex, income, and various comorbidities. The primary outcome was the incidence of tuberculosis during the follow-up period. Our study comprised 90,886 gastrectomy patients and 46,759 endoscopic resection patients. The tuberculosis incidence was significantly higher in the gastrectomy group compared to its matched non-gastrectomy group (IRR 1.69, 95% CI 1.43-1.99, p < .001). In contrast, there was no significant difference in tuberculosis incidence between the endoscopic resection group and its matched non-resection group (IRR 0.95, 95% CI 0.75-1.19, p = 0.627). The Kaplan-Meier cumulative incidence also did not differ between the two groups. However, tuberculosis incidence significantly increased in the first year after endoscopic resection. Gastrectomy for gastric cancer is associated with a higher incidence of subsequent tuberculosis, while no significant association was observed for endoscopic resection. However, tuberculosis incidence increases significantly during the first year after endoscopic resection.

Effectiveness of a Fourth COVID-19 mRNA Vaccine Dose Against the Omicron Variant in Solid Organ Transplant Recipients.

The effectiveness of booster doses of COVID-19 vaccines in solid organ transplant recipients is unclear. We conducted a population-based matched cohort study using linked administrative healthcare databases from Ontario, Canada to estimate the marginal vaccine effectiveness of a fourth versus third dose of the BNT162b2 and mRNA-1273 vaccines against clinically important outcomes (ie, hospitalization or death) and infection during the era of the Omicron variant. We matched 3120 solid organ transplant recipients with a third COVID-19 vaccine dose (reference) to 3120 recipients with a fourth dose. Recipients were matched on the third dose date (±7 d). We used a multivariable Cox proportional hazards model to estimate the marginal vaccine effectiveness with outcomes occurring between December 21, 2021 and April 30, 2022. The cumulative incidence of COVID-19-related hospitalization or death was 2.8% (95% confidence interval [CI], 2.0-3.7) in the third dose group compared with 1.1% (95% CI, 0.59-1.8) in the fourth dose group after 84 d of follow-up (P < 0.001). The adjusted marginal vaccine effectiveness was 70% (95% CI, 47-83) against clinically important outcomes and 39% (95% CI, 21-52) against SARS-CoV-2 infection. Compared with a third dose, a fourth dose of the COVID-19 vaccine was associated with improved protection against hospitalization, death, and SARS-CoV-2 infection during the Omicron era. Results highlight the importance of a booster COVID-19 vaccine dose in solid organ transplant recipients.

Pregnancy Weight Gain After Gastric Bypass or Sleeve Gastrectomy

Pregnancy weight gain may affect the association of bariatric surgery with postsurgery pregnancy outcomes. However, the association of pregnancy weight gain with bariatric surgery is unclear. To compare pregnancy weight gain among women with a history of bariatric surgery vs those without and to investigate whether pregnancy weight gain differs by surgical procedure, surgery-to-conception interval, and/or surgery-to-conception weight loss. This nationwide, population-based matched cohort study was conducted in Sweden from 2014 to 2021. Singleton pregnancies with a history of bariatric surgery were propensity score matched (1:1) to pregnancies without such a history according to early-pregnancy body mass index (BMI), prepregnancy diabetes, prepregnancy hypertension, maternal age, smoking status, education level, height, country of birth, and delivery year. In addition, post-gastric bypass pregnancies were matched to post-sleeve gastrectomy pregnancies using the same matching strategy. Data analysis was performed from November 2022 to May 2023. History of bariatric surgery. Pregnancy weight gain was standardized by gestational age into early-pregnancy BMI-specific z scores. This study included 12 776 pregnancies, of which 6388 had a history of bariatric surgery and 6388 were matched controls. The mean (SD) age was 31.6 (4.9) years for the surgery group and 31.4 (5.2) for the matched controls, with an early-pregnancy mean (SD) BMI of 29.4 (5.2) in both groups. Across all early-pregnancy BMI strata, women with a history of bariatric surgery had lower pregnancy weight gain than matched controls. The differences in pregnancy weight gain z score values between the 2 groups were -0.33 (95% CI, -0.43 to -0.23) for normal weight, -0.33 (95% CI, -0.40 to -0.27) for overweight, -0.21 (95% CI, -0.29 to -0.13) for obese class I, -0.16 (95% CI, -0.29 to -0.03) for obese class II, and -0.08 (95% CI, -0.28 to 0.13) for obese class III. Pregnancy weight gain did not differ by surgical procedure. A shorter surgery-to-conception interval (particularly within 1 year) or lower surgery-to-conception weight loss was associated with lower pregnancy weight gain. In this nationwide matched cohort study, women with a history of bariatric surgery had lower pregnancy weight gain than matched controls with similar early-pregnancy characteristics. Pregnancy weight gain was lower in those with a shorter surgery-to-conception interval or lower surgery-to-conception weight loss, but did not differ by surgical procedure.

EPH38 Exploring the Relationship Between Hemochromatosis and Fracture Risk: A Population-Based Matched Cohort Study Stratified on Ferritin Levels

EPH38 Exploring the Relationship Between Hemochromatosis and Fracture Risk: A Population-Based Matched Cohort Study Stratified on Ferritin Levels