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

Background: 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.

Objective: To assess the association between acute pancreatitis and the risk of BTC.

Decreased Risk of Esophageal Adenocarcinoma After Gastric Bypass Surgery in a Cohort Study From 3 Nordic Countries.

Objective: The objective of this study was to test the hypothesis that bariatric surgery decreases the risk of esophageal and cardia adenocarcinoma.

Background: Obesity is strongly associated with esophageal adenocarcinoma and moderately with cardia adenocarcinoma, but whether weight loss prevents these tumors is unknown.

Methods: This population-based cohort study included patients with an obesity diagnosis in Sweden, Finland, or Denmark.

Mortality in small bowel cancers and adenomas - A nationwide, population-based matched cohort study.

Background: Small bowel adenocarcinoma (SBA), neuroendocrine tumors (NET) and gastrointestinal stromal tumors (GIST) are neoplastic lesions of the small bowel while small bowel adenomas are precursors of SBA.

Aim: To examine mortality in patients diagnosed with SBA, small bowel adenomas, NET and GIST.

Methods: We performed a population-based matched cohort study encompassing all individuals with SBA (n = 2289), adenomas (n = 3700), NET (n = 1884) and GIST (n = 509) in the small bowel diagnosed at any of Sweden's 28 pathology departments between 2000 and 2016 (the "ESPRESSO study").

Proton pump inhibitor use and risk of pneumonia: a self-controlled case series study.

Background: Recent research indicates that use of proton pump inhibitors (PPIs) is associated with pneumonia, but existing evidence is inconclusive because of methodological issues. This study aimed to answer whether PPI-use increases risk of pneumonia while taking the methodological concerns of previous research into account.

Methods: This population-based and nationwide Swedish study conducted in 2005-2019 used a self-controlled case series design.

Objectively confirmed gastroesophageal reflux disease and risk of atrial fibrillation: a population-based cohort study in Sweden.

Objective: This study aimed to determine the risk of atrial fibrillation in patients with objectively confirmed GERD.

Methods: This was a nationwide population-based cohort study between 2005 and 2018, including the majority ( n = 8 421 115) of all Swedish adult residents (≥18 years). Within this cohort, the exposed group were all individuals with a diagnosis of esophagitis or Barrett's esophagus, and the unexposed group was made up of five times as many individuals without any GERD, matched by age, sex, and calendar year.

Appendectomy and Future Risk of Microscopic Colitis: A Population-Based Case-Control Study in Sweden.

Background And Aims: Microscopic colitis (MC) is an inflammatory bowel disease and a common cause of chronic diarrhea. Appendectomy has been suggested to have immunomodulating effects in the colon, influencing the risk of gastrointestinal disease. The relationship between appendectomy and MC has only been sparsely studied.

Cohort profile: the Swedish Pancreatitis Cohort (SwePan).

Purpose: The Swedish Pancreatitis Cohort (SwePan) was designed to study long-term outcomes following an episode of acute pancreatitis. It can also be used to study various risk factors for developing acute pancreatitis.

Participants: The SwePan is a register-based nationwide matched cohort.

Incidence and Mortality in Upper Gastrointestinal Cancer After Negative Endoscopy for Gastroesophageal Reflux Disease.

Background And Aims: Gastroesophageal reflux disease (GERD) is associated with an increased risk of cancer of the upper gastrointestinal tract. This study aimed to assess whether and to what extent a negative upper endoscopy in patients with GERD is associated with decreased incidence and mortality in upper gastrointestinal cancer (ie, esophageal, gastric, or duodenal cancer).

Methods: We conducted a population-based cohort study of all patients with newly diagnosed GERD between July 1, 1979 and December 31, 2018 in Denmark, Finland, Norway, and Sweden.

Proton Pump Inhibitor and Clopidogrel Use After Percutaneous Coronary Intervention and Risk of Major Cardiovascular Events.

Purpose: Due to shared hepatic metabolism, concomitant medication with a proton pump inhibitor (PPI) and clopidogrel might reduce the effectiveness of clopidogrel in the prevention of cardiovascular events after percutaneous coronary intervention (PCI). We aimed to examine the risk of major cardiovascular events after PCI comparing patients who used clopidogrel together with PPI with those who used clopidogrel alone.

Methods: This Swedish nationwide cohort study included patients who received clopidogrel after primary PCI in 2005-2019.

Mortality, Reoperation, and Hospital Stay Within 90 Days of Primary and Secondary Antireflux Surgery in a Population-Based Multinational Study.

Background & Aims: Absolute rates and risk factors of short-term outcomes after antireflux surgery remain largely unknown. We aimed to clarify absolute risks and risk factors for poor 90-day outcomes of primary laparoscopic and secondary antireflux surgery.

Methods: This population-based cohort study included patients who had primary laparoscopic or secondary antireflux surgery in the 5 Nordic countries in 2000-2018.

Gastroesophageal Reflux Disease: A Review.

Importance: Gastroesophageal reflux disease (GERD) is defined by recurrent and troublesome heartburn and regurgitation or GERD-specific complications and affects approximately 20% of the adult population in high-income countries.

Observations: GERD can influence patients' health-related quality of life and is associated with an increased risk of esophagitis, esophageal strictures, Barrett esophagus, and esophageal adenocarcinoma. Obesity, tobacco smoking, and genetic predisposition increase the risk of developing GERD.

Laryngeal and Pharyngeal Squamous Cell Carcinoma After Antireflux Surgery in the 5 Nordic Countries.

Objective: The aim of this study was to clarify whether antireflux surgery prevents laryngeal and pharyngeal squamous cell carcinoma.

Summary Background Data: Gastroesophageal reflux disease (GERD) seems to increase the risk of laryngeal and pharyngeal squamous cell carcinoma.

Methods: All-Nordic (Denmark, Finland, Iceland, Norway, and Sweden) population-based cohort study of adults with documented GERD in 1980 to 2014.

Antireflux surgery and risk of lung cancer by histological type in a multinational cohort study.

Introduction: Airway micro-aspiration might contribute to the proposed associations between gastroesophageal reflux disease (GERD) and some lung diseases, including lung cancer. This study aimed to examine the hypothesis that antireflux surgery decreases the risk of small cell carcinoma, squamous cell carcinoma and adenocarcinoma of the lung differently depending on their location in relation to micro-aspiration.

Methods: Population-based cohort study including patients having undergone antireflux surgery during 1980-2014 in Denmark, Finland, Iceland, Norway or Sweden.

Hospital volume of esophageal cancer surgery in relation to outcomes from primary anti-reflux surgery.

No previous study has sought to identify the effect of hospital volume of esophagectomy on anti-reflux surgery outcomes. The hypothesis under investigation was hospitals performing esophagectomies, particularly those of higher annual volume, have better outcomes from primary anti-reflux surgery. This population-based cohort study included adult individuals (≥18 years) in Sweden receiving primary anti-reflux surgery for a recorded gastro-esophageal reflux disease in 1997-2010, with follow-up until 2013 The 'exposure' was hospital volume of esophagectomy, with hospitals conducting esophagectomies divided into 0, >0-1, >1-3 and ≥ 4 based on annual volume, and hospitals not conducting esophagectomies were the reference category.

Aspiration pneumonia after antireflux surgery among neurologically impaired children with GERD.

Background And Objective: Aspiration pneumonia is a common and serious complication to gastroesophageal reflux disease (GERD) among neurologically impaired children. Medication of GERD does not effectively prevent aspiration pneumonia, and whether antireflux surgery with fundoplication is better in this respect is uncertain. The objective was to determine whether fundoplication prevents aspiration pneumonia among children with neurological impairment and GERD.

Hospital Volume of Antireflux Surgery in Relation to Endoscopic and Surgical Re-interventions.

Objective: To test the hypothesis that higher hospital volume decreases endoscopic and surgical re-intervention rates after antireflux surgery.

Background: Antireflux surgery for gastro-esophageal reflux disease is followed by varying rates of re-interventions. Whether hospital volume influences re-intervention rates is uncertain.

Esophageal Adenocarcinoma After Antireflux Surgery in a Cohort Study From the 5 Nordic Countries.

Objective: We aimed to clarify the long-term risk development of EAC after antireflux surgery.

Summary Of Background Data: Gastroesophageal reflux disease (GERD) increases EAC risk, but whether antireflux surgery prevents EAC is uncertain.

Methods: Multinational, population-based cohort study including individuals with GERD from all 5 Nordic countries in 1964-2014.

Risk of Esophageal Adenocarcinoma After Antireflux Surgery in Patients With Gastroesophageal Reflux Disease in the Nordic Countries.

Importance: Gastroesophageal reflux disease (GERD) is associated with a strong and severity-dependent increased risk of esophageal adenocarcinoma. Whether antireflux surgery prevents esophageal adenocarcinoma is a matter of uncertainty.

Objectives: To examine whether antireflux surgery is associated with reduced risk of esophageal adenocarcinoma and whether the risk is different between surgically and medically treated patients.

Association Between Laparoscopic Antireflux Surgery and Recurrence of Gastroesophageal Reflux.

Importance: Cohort studies, mainly based on questionnaires and interviews, have reported high rates of reflux recurrence after antireflux surgery, which may have contributed to a decline in its use. Reflux recurrence after laparoscopic antireflux surgery has not been assessed in a long-term population-based study of unselected patients.

Objectives: To determine the risk of reflux recurrence after laparoscopic antireflux surgery and to identify risk factors for recurrence.

Nordic registry-based cohort studies: Possibilities and pitfalls when combining Nordic registry data.

Aims: All five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) have nationwide registries with similar data structure and validity, as well as personal identity numbers enabling linkage between registries. These resources provide opportunities for medical research that is based on large registry-based cohort studies with long and complete follow-up. This review describes practical aspects, opportunities and challenges encountered when setting up all-Nordic registry-based cohort studies.