Ascertainment of Infection and Eradication Treatment Using a Nationwide Electronic Health Record Database.

Background And Aims: There are limited contemporary population-based data on epidemiology and outcomes in the United States. Our primary aim was to create a validated cohort of veterans with testing or treatment using Veterans Health Administration data.

Methods: Using Veterans Health Administration structured and unstructured data, we developed and validated 4 algorithms for infection (3 algorithms) and treatment status (1 algorithm).

Pancreatic cyst features predict future development of pancreatic cancer: results of a nested case-control study.

Background And Aims: Risk factors for pancreatic cancer among patients with pancreatic cysts are incompletely characterized. The primary aim of this study was to evaluate risk factors for development of pancreatic cancer among patients with pancreatic cysts.

Methods: We conducted a retrospective case-control study of U.

Risk of Incident and Fatal Colorectal Cancer After Young-Onset Adenoma Diagnosis: A National Cohort Study.

Introduction: Colorectal cancer (CRC) incidence and mortality rates are increasing in adults aged <50 years. Young-onset adenoma (YOA)-adenoma detected in adults younger than 50 years-may signify increased CRC risk, but this association has not been widely studied. Our aim was to compare the risk of incident and fatal CRC in adults aged <50 years with YOA diagnosis compared with those with a normal colonoscopy.

Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy.

Background And Aims: Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors.

Methods: We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.

Baseline Characteristics and Longitudinal Outcomes of Traditional Serrated Adenomas: A Cohort Study.

Background And Aims: Traditional serrated adenomas (TSAs) may confer increased risk for colorectal cancer (CRC). Our objective with this study was to examine clinical characteristics and long-term outcomes associated with TSA diagnosis.

Methods: We conducted a retrospective cohort study of U.

COVID-19 Pandemic Had Minimal Impact on Colonoscopy Completion After Colorectal Cancer Red Flag Sign or Symptoms in US Veterans.

Background: Delays in colonoscopy work-up for red flag signs or symptoms of colorectal cancer (CRC) during the COVID-19 pandemic are not well characterized.

Aims: To examine colonoscopy uptake and time to colonoscopy after red flag diagnosis, before and during the COVID-19 pandemic.

Methods: Cohort study of adults ages 50-75 with iron deficiency anemia (IDA), hematochezia, or abnormal stool blood test receiving Veterans Health Administration (VHA) care from April 2019 to December 2020.

A strategy for validation of variables derived from large-scale electronic health record data.

Purpose: Standardized approaches for rigorous validation of phenotyping from large-scale electronic health record (EHR) data have not been widely reported. We proposed a methodologically rigorous and efficient approach to guide such validation, including strategies for sampling cases and controls, determining sample sizes, estimating algorithm performance, and terminating the validation process, hereafter referred to as the San Diego Approach to Variable Validation (SDAVV).

Methods: We propose sample size formulae which should be used prior to chart review, based on pre-specified critical lower bounds for positive predictive value (PPV) and negative predictive value (NPV).

Pancreas Cancer Incidence and Pancreas Cancer-Associated Mortality Are Low in National Cohort of 7211 Pancreas Cyst Patients.

Background And Aims: Pancreatic cancer incidence and mortality among patients with pancreas cysts are unclear. The aims of this study are to evaluate incidence of pancreatic cancer and cause-specific mortality among patients with pancreatic cysts using a large national cohort over a long follow-up period.

Methods: We conducted a retrospective cohort study of US Veterans diagnosed with a pancreatic cyst 1999-2013, based on International Classification of Diseases, 9th edition (ICD9) coding within national Department of Veterans Affairs (VA) data.

Systematic Review of Prevalence, Risk Factors, and Risk for Metachronous Advanced Neoplasia in Patients With Young-Onset Colorectal Adenoma.

Background & Aims: The incidence and mortality of early-onset colorectal cancer (CRC) are increasing. Adenoma detection, removal, and subsequent endoscopic surveillance might modify risk of CRC diagnosed before age 50 years (early-onset CRC). We conducted a systematic review of young-onset adenoma (YOA) prevalence, associated risk factors, and rate of metachronous advanced neoplasia after YOA diagnosis.

Risk Factors for Early-Onset Colorectal Cancer.

Background & Aims: Colorectal cancer (CRC) incidence and mortality are increasing among persons younger than 50 years old in the United States, but risk factors associated with early-onset CRC (EOCRC) have not been widely studied.

Methods: We conducted a case-control study of US veterans 18 to 49 years old who underwent colonoscopy examinations from 1999 through 2014. EOCRC cases were identified from a national cancer registry; veterans who were free of CRC at their baseline colonoscopy through 3 years of follow-up were identified as controls.

Metformin Is Associated With Reduced Odds for Colorectal Cancer Among Persons With Diabetes.

Introduction: Metformin may be associated with reduced colorectal cancer (CRC) risk, but findings from previous studies have been inconsistent and had insufficient sample sizes to examine whether the association differs by anatomic site. This study examined whether metformin was associated with reduced CRC risk, both overall and stratified by anatomic site, in a large sample of persons with diabetes who underwent colonoscopy.

Methods: We performed a case-control study of US Veterans with prevalent diabetes who underwent colonoscopy between 1999 and 2014 using Department of Veterans Affairs electronic health record data.

Risk factors for colorectal cancer significantly vary by anatomic site.

Objective: To conduct an anatomic site-specific case-control study of candidate colorectal cancer (CRC) risk factors.

Design: Case-control study of US veterans with >1 colonoscopy during 1999-2011. Cases had cancer registry-identified CRC at colonoscopy, while controls were CRC free at colonoscopy and within 3 years of colonoscopy.

Ascertainment of Aspirin Exposure Using Structured and Unstructured Large-scale Electronic Health Record Data.

Background: Aspirin impacts risk for important outcomes such as cancer, cardiovascular disease, and gastrointestinal bleeding. However, ascertaining exposure to medications available both by prescription and over-the-counter such as aspirin for research and quality improvement purposes is a challenge.

Objectives: Develop and validate a strategy for ascertaining aspirin exposure, utilizing a combination of structured and unstructured data.

Structured Approach for Evaluating Strategies for Cancer Ascertainment Using Large-Scale Electronic Health Record Data.

Purpose: Cancer ascertainment using large-scale electronic health records is a challenge. Our aim was to propose and apply a structured approach for evaluating multiple candidate approaches for cancer ascertainment using colorectal cancer (CRC) ascertainment within the US Department of Veterans Affairs (VA) as a use case.

Methods: The proposed approach for evaluating cancer ascertainment strategies includes assessment of individual strategy performance, comparison of agreement across strategies, and review of discordant diagnoses.

A Framework for Leveraging "Big Data" to Advance Epidemiology and Improve Quality: Design of the VA Colonoscopy Collaborative.

Objective: To describe a framework for leveraging big data for research and quality improvement purposes and demonstrate implementation of the framework for design of the Department of Veterans Affairs (VA) Colonoscopy Collaborative.

Methods: We propose that research utilizing large-scale electronic health records (EHRs) can be approached in a 4 step framework: 1) Identify data sources required to answer research question; 2) Determine whether variables are available as structured or free-text data; 3) Utilize a rigorous approach to refine variables and assess data quality; 4) Create the analytic dataset and perform analyses. We describe implementation of the framework as part of the VA Colonoscopy Collaborative, which aims to leverage big data to 1) prospectively measure and report colonoscopy quality and 2) develop and validate a risk prediction model for colorectal cancer (CRC) and high-risk polyps.