Scholars@Duke
Ziad F. Gellad

Ziad F. Gellad

Professor of Medicine
Medicine, Gastroenterology
ziad.gellad@duke.edu
Box 3913, Durham, NC 27710
508 Fulton Street, 111E GI Clinic, Durham, NC 27705

Selected Publications

Real World Characterization of Chronic Pain, Success Rates and Implant Rates: Evidence from a Digital Health Platform of Patients Undergoing Spinal Cord Stimulation Evaluations.

Journal Article J Pain · December 2023 Spinal cord stimulation is an effective treatment for those experiencing chronic back and leg pain but requires a temporary evaluation period (SCSeval) before permanent implantation. We present real-world data from 7,000 patients who underwent SCSeval whil ... Full text Link to item Cite

Improving patient outcomes with a mobile digital health platform for patients undergoing transcatheter aortic valve replacement.

Journal Article J Invasive Cardiol · September 2023 PURPOSE: ManageMySurgery (MMS) is a digital health application (app) for patients undergoing surgery, including Transcatheter Aortic Valve Replacement (TAVR). Patients using MMS review procedure-specific education, view FAQs, and report patient-reported ou ... Full text Link to item Cite

AGA Clinical Practice Update on Telemedicine in Gastroenterology: Commentary.

Journal Article Gastroenterology · April 2023 DESCRIPTION: The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) is to review the available evidence and provide expert advice regarding best practices for use of telemedicine in gastroenterology and ... Full text Link to item Cite

Outcomes With a Mobile Digital Health Platform for Patients Undergoing Spine Surgery: Retrospective Analysis.

Journal Article JMIR Perioper Med · October 26, 2022 BACKGROUND: Digital health solutions have been shown to enhance outcomes for individuals with chronic medical illnesses, but few have been validated for surgical patients. The digital health platform ManageMySurgery (MMS) has been validated for spine surge ... Full text Link to item Cite

Longitudinal assessment of colonoscopy adverse events in the prospective Cooperative Studies Program no. 380 colorectal cancer screening and surveillance cohort.

Journal Article Gastrointest Endosc · September 2022 BACKGROUND AND AIMS: Data are limited regarding colonoscopy risk during long-term, programmatic colorectal cancer screening and follow-up. We aimed to describe adverse events during follow-up in a colonoscopy screening program after the baseline examinatio ... Full text Link to item Cite

Feasibility study of a novel digital health platform for patients undergoing transcatheter aortic valve replacement.

Journal Article J Card Surg · July 2022 INTRODUCTION: Despite abundant evidence indicating that digital health solutions improve outcomes in chronic medical conditions, there are few validated solutions for acute surgical episodes. Transcatheter aortic valve replacement (TAVR) is a less invasive ... Full text Link to item Cite

Ten or More Cumulative Lifetime Adenomas Are Associated with Increased Risk for Advanced Neoplasia and Colorectal Cancer.

Journal Article Dig Dis Sci · June 2022 BACKGROUND: Colorectal cancer (CRC) screening guidelines recommend frequent colonoscopies and consideration of genetic testing in individuals with ≥10 cumulative adenomas. However, it is unclear how these guidelines apply to routine practice. AIMS: We esti ... Full text Link to item Cite

Practice Management: The Road Taken and the Road Ahead.

Journal Article Clin Gastroenterol Hepatol · June 2022 Full text Link to item Cite

Screening Colonoscopy Findings Are Associated With Noncolorectal Cancer Mortality.

Journal Article Clin Transl Gastroenterol · April 1, 2022 INTRODUCTION: Controversy exists regarding the impact of various risk factors on noncolorectal cancer (CRC) mortality in healthy screening populations. We examined the impact of known CRC risk factors, including baseline colonoscopy findings, on non-CRC mo ... Full text Link to item Cite

Racial and Socioeconomic Disparities in Utilization of Telehealth in Patients with Liver Disease During COVID-19.

Journal Article Dig Dis Sci · January 2022 BACKGROUND AND AIMS: The coronavirus disease 2019 (COVID-19) pandemic resulted in a rapid expansion of telehealth services in hepatology. However, known racial and socioeconomic disparities in internet access potentially translate into barriers for the use ... Full text Link to item Cite

Issue Highlights.

Journal Article Clin Gastroenterol Hepatol · November 2021 Full text Link to item Cite

Mobile Health Application for Patients Undergoing Breast Cancer Surgery: Feasibility Study.

Journal Article JCO Oncol Pract · September 2021 PURPOSE: Contemporary breast cancer surgery often requires hospital stays of 1 day or less, presenting challenges to delivery of high-quality care. Without sufficient time for proper education and guidance, patients may delay seeking care, experience anxie ... Full text Link to item Cite

Patient, Physician, and Procedure Characteristics Are Independently Predictive of Polyp Detection Rates in Clinical Practice.

Journal Article Digestive diseases and sciences · August 2021 BackgroundVariability in colon polyp detection impacts patient outcomes. However, the relative influence of physician, patient, and procedure-specific factors on polyp detection is unclear. Therefore, determining how these factors contribute to ad ... Full text Cite

Characterizing chronological accumulation of comorbidities in healthy veterans: a computational approach.

Journal Article Sci Rep · April 14, 2021 Understanding patient accumulation of comorbidities can facilitate healthcare strategy and personalized preventative care. We applied a directed network graph to electronic health record (EHR) data and characterized comorbidities in a cohort of healthy vet ... Full text Open Access Link to item Cite

Esophageal contractile segment impedance from high-resolution impedance manometry correlates with mean nocturnal baseline impedance and acid exposure time from 24-hour pH-impedance monitoring.

Journal Article Dis Esophagus · December 7, 2020 Esophageal baseline impedance (BI) acquired during esophageal contraction (contractile segment impedance [CSI]) is proposed to improve BI accuracy in gastroesophageal reflux disease (GERD). We evaluated associations between CSI and conventional and novel G ... Full text Link to item Cite

Genetic Colorectal Cancer and Adenoma Risk Variants Are Associated with Increasing Cumulative Adenoma Counts.

Conference Cancer Epidemiol Biomarkers Prev · November 2020 BACKGROUND: The genetic basis for most individuals with high cumulative lifetime colonic adenomas is unknown. We investigated associations between known colorectal cancer-risk single-nucleotide polymorphisms (SNP) and increasing cumulative adenoma counts. ... Full text Link to item Cite

A Smartphone App With a Digital Care Pathway for Patients Undergoing Spine Surgery: Development and Feasibility Study.

Journal Article JMIR Perioper Med · October 16, 2020 BACKGROUND: There is a great unmet clinical need to provide patients undergoing spinal surgery and their caregivers with ongoing, high-quality care before and after surgery in an efficiency-focused health care environment. OBJECTIVE: The objective of this ... Full text Open Access Link to item Cite

Issue Highlights

Journal Article Clinical Gastroenterology and Hepatology · October 1, 2020 Full text Cite

Esophageal Baseline Impedance From High-resolution Impedance Manometry Correlates With Mean Nocturnal Baseline Impedance From pH-impedance Monitoring.

Journal Article J Neurogastroenterol Motil · September 30, 2020 BACKGROUND/AIMS: Esophageal baseline impedance (BI) can be extracted from pH-impedance tracings as mean nocturnal baseline impedance (MNBI), and from high-resolution impedance manometry (HRIM), but it is unknown if values are similar between acquisition me ... Full text Link to item Cite

Terminal ileum intubation is not associated with colonoscopy quality measures.

Journal Article J Gastroenterol Hepatol · September 2020 BACKGROUND AND AIM: Intubation of the terminal ileum (TI) demonstrates a complete colonoscopy, but its clinical value during screening exams is unknown. We aimed to determine whether TI intubation during screening colonoscopy is associated with colonoscopy ... Full text Open Access Link to item Cite

High-Risk Adenomas at Screening Colonoscopy Remain Predictive of Future High-Risk Adenomas Despite an Intervening Negative Colonoscopy.

Journal Article Am J Gastroenterol · August 2020 INTRODUCTION: Limited data inform the current postpolypectomy surveillance guidelines, which suggest a shortened interval to third colonoscopy after a negative second examination if high-risk adenomas (HRA) were present on the initial screening colonoscopy ... Full text Link to item Cite

Telehealth transformation: COVID-19 and the rise of virtual care.

Journal Article J Am Med Inform Assoc · June 1, 2020 The novel coronavirus disease-19 (COVID-19) pandemic has altered our economy, society, and healthcare system. While this crisis has presented the U.S. healthcare delivery system with unprecedented challenges, the pandemic has catalyzed rapid adoption of te ... Full text Open Access Link to item Cite

Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance.

Journal Article Gastroenterology · March 2020 BACKGROUND & AIMS: Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous h ... Full text Link to item Cite

Advanced neoplasia in Veterans at screening colonoscopy using the National Cancer Institute Risk Assessment Tool.

Journal Article BMC Cancer · November 12, 2019 BACKGROUND: Adapting screening strategy to colorectal cancer (CRC) risk may improve efficiency for all stakeholders however limited tools for such risk stratification exist. Colorectal cancers usually evolve from advanced neoplasms that are present for yea ... Full text Link to item Cite

Randomized Trial of Medical versus Surgical Treatment for Refractory Heartburn.

Journal Article N Engl J Med · October 17, 2019 BACKGROUND: Heartburn that persists despite proton-pump inhibitor (PPI) treatment is a frequent clinical problem with multiple potential causes. Treatments for PPI-refractory heartburn are of unproven efficacy and focus on controlling gastroesophageal refl ... Full text Link to item Cite

Content Validity and Reliability of a Self-Report Measure of Medication Nonadherence in Hepatitis C Treatment.

Journal Article Dig Dis Sci · October 2019 BACKGROUND: Nonadherence to direct-acting agents (DAAs) for hepatitis C (HCV) decreases viral response. To measure nonadherence to DAAs, a reliable, valid, and easily implemented method is needed. AIMS: The goals of this study were to refine a previously v ... Full text Link to item Cite

Issue Highlights

Journal Article Clinical Gastroenterology and Hepatology · September 1, 2019 Full text Cite

Adoption of direct-acting antiviral medications for hepatitis C: a retrospective observational study.

Journal Article BMC Health Serv Res · July 25, 2019 BACKGROUND: Approximately 3.5 million Americans are infected with the hepatitis C virus (HCV). Although many patients with HCV are asymptomatic, HCV is the leading cause of infection-related death in the U.S. With advances in curative medication therapy fo ... Full text Open Access Link to item Cite

Characterization of temporal relationships of comorbidities developed following cancer diagnoses in veterans.

Conference Journal of Clinical Oncology · May 20, 2019 e18049 Background: Understanding patient trajectories and common sequences of comorbidity accrual among those newly diagnosed with cancer is critical for precision approaches to care and prevention. The Veterans Affairs (VA) Coop ... Full text Cite

A Roadmap for Value-Based Payment Models Among Patients With Cirrhosis.

Journal Article Hepatology · March 2019 Healthcare reimbursement is shifting from fee-for-service to fee-for-value. Cirrhosis, which costs the U.S. healthcare system as much as heart failure, is a prime target for value-based care. This article describes models in which physician groups or healt ... Full text Link to item Cite

Issue Highlights.

Journal Article Clin Gastroenterol Hepatol · October 2018 Full text Link to item Cite

Designing risk prediction models for ambulatory no-shows across different specialties and clinics.

Journal Article J Am Med Inform Assoc · August 1, 2018 OBJECTIVE: As available data increases, so does the opportunity to develop risk scores on more refined patient populations. In this paper we assessed the ability to derive a risk score for a patient no-showing to a clinic visit. METHODS: Using data from 2  ... Full text Open Access Link to item Cite

Factors Associated With Emergency Department Visits and Hospital Admissions After Invasive Outpatient Procedures in the Veterans Health Administration.

Journal Article JAMA Surg · August 1, 2018 This study evaluates the prevalence of postprocedure emergency department visits and admissions and the association of these outcomes with relevant patient, procedure, and facility factors. ... Full text Link to item Cite

Improving Quality in the Care of Patients with Inflammatory Bowel Diseases.

Journal Article Inflamm Bowel Dis · July 12, 2018 Efforts to improve healthcare quality were firmly established before the Institute of Medicine (IOM) historic 2000 and 2001 reports, To Err is Human Building a Safer Health System and Crossing the Quality Chasm: A New Health System for the 21st Century Des ... Full text Link to item Cite

Issue Highlights.

Journal Article Clin Gastroenterol Hepatol · October 2017 Full text Link to item Cite

Bolus Administration of Fentanyl and Midazolam for Colonoscopy Increases Endoscopy Unit Efficiency and Safety Compared With Titrated Sedation.

Journal Article Clin Gastroenterol Hepatol · September 2017 BACKGROUND & AIMS: Guidelines recommend slow titration of sedatives for moderate sedation. Bolus sedation, in which a larger weight-based dose of medication is given upfront, has been shown in a single trial to be beneficial. We evaluated the effects of bo ... Full text Link to item Cite

Cultivating Competencies for Value-Based Care.

Journal Article Clin Gastroenterol Hepatol · July 2017 Full text Link to item Cite

Reply.

Journal Article Clin Gastroenterol Hepatol · March 2016 Full text Link to item Cite

Factors Associated With Missed and Cancelled Colonoscopy Appointments at Veterans Health Administration Facilities.

Journal Article Clin Gastroenterol Hepatol · February 2016 BACKGROUND & AIMS: Cancelled and missed colonoscopy appointments waste resources, increase colonoscopy delays, and can adversely affect patient outcomes. We examined individual and organizational factors associated with missed and cancelled colonoscopy app ... Full text Link to item Cite

Toward a Learning Health-Care System: Use of Colorectal Cancer Quality Measures for Physician Evaluation

Chapter · January 1, 2015 The development of evidence-based quality measures and benchmarks in colorectal cancer (CRC) screening is a critical step toward building a truly accountable health-care system. Indeed, much of the gastroenterology research literature in quality has focuse ... Full text Cite

Endoscopy unit efficiency.

Journal Article Gastroenterol Hepatol (N Y) · May 2014 Link to item Cite

Reply: To PMID 23978500.

Journal Article Clin Gastroenterol Hepatol · March 2014 Full text Link to item Cite

Physician perceptions on colonoscopy quality: results of a national survey of gastroenterologists.

Journal Article Gastroenterol Res Pract · 2014 Background. Quality indicators for colonoscopy have been developed, but the uptake of these metrics into practice is uncertain. Our aims were to assess physician perceptions regarding colonoscopy quality measurement and to quantify the perceived impact of ... Full text Link to item Cite

Simulation as a guide for systems redesign in gastrointestinal endoscopy: Appointment template redesign

Journal Article Proceedings of the 2013 Winter Simulation Conference Simulation Making Decisions in A Complex World Wsc 2013 · December 1, 2013 In this era of health care value-based purchasing, health care systems are increasingly focused on maximizing the utilization of their most expensive resources. This trend is evident in gastrointestinal endoscopy which makes up the largest percentage of am ... Full text Cite

Impact of Propofol on Endoscopy Unit Efficiency: A Discrete Event Simulation Model

Conference American Journal of Gastroenterology · October 2013 Full text Cite

Endoscopy unit efficiency: quality redefined.

Journal Article Clin Gastroenterol Hepatol · September 2013 Full text Link to item Cite

Personalisation of colorectal cancer screening.

Journal Article Lancet Oncol · July 2013 Featured Publication Full text Link to item Cite

Clinical practice variation in the management of diminutive colorectal polyps: results of a national survey of gastroenterologists.

Journal Article Am J Gastroenterol · June 2013 Featured Publication OBJECTIVES: We investigated physician beliefs and behaviors regarding diminutive colorectal polyps and the contribution of these beliefs to variable detection rates. METHODS: One hundred sixty-seven members of the American College of Gastroenterology took ... Full text Link to item Cite

Using NCCN clinical practice guidelines in oncology to measure the quality of colorectal cancer care in the veterans health administration.

Journal Article J Natl Compr Canc Netw · April 1, 2013 Featured Publication Clinical practice guidelines can be used to help develop measures of quality of cancer care. This article describes the use of a Cancer Care Quality Measurement System (CCQMS) to monitor these measures for colorectal cancer in the Veterans Health Administr ... Full text Link to item Cite

A simulation study to reduce nurse overtime and improve patient flow time at a hospital endoscopy unit

Journal Article Proceedings Winter Simulation Conference · December 1, 2012 Featured Publication Increasing demand for endoscopic procedures, coupled with decreasing insurance reimbursement, has necessitated improvement in endoscopy unit operational performance measures, such as increasing throughput and reducing staff overtime without an increase in ... Full text Cite

Comparative effectiveness of i-SCAN™ and high-definition white light characterizing small colonic polyps.

Journal Article World J Gastroenterol · November 7, 2012 Featured Publication AIM: To evaluate accuracy of in vivo diagnosis of adenomatous vs non-adenomatous polyps using i-SCAN digital chromoendoscopy compared with high-definition white light. METHODS: This is a single-center comparative effectiveness pilot study. Polyps (n = 103) ... Full text Link to item Cite

Cost-effectiveness of truncated therapy for hepatitis C based on rapid virologic response.

Journal Article Value Health · 2012 Featured Publication BACKGROUND: Shortened courses of treatment with pegylated interferon alfa and ribavirin for patients with hepatitis C virus infection who experience rapid virologic response can be effective in appropriately selected patients. The cost-effectiveness of tru ... Full text Link to item Cite

Economic evaluation of direct-acting antiviral therapy in chronic hepatitis C.

Journal Article Antivir Ther · 2012 Featured Publication In 2011, the protease inhibitors boceprevir and telaprevir were approved in the United States and European Union for the treatment of hepatitis C infection. While remarkably effective, the newly approved therapies are also accompanied by additional side ef ... Full text Link to item Cite

Longitudinal adherence to fecal occult blood testing impacts colorectal cancer screening quality.

Journal Article Am J Gastroenterol · June 2011 Featured Publication OBJECTIVES: Existing cross-sectional quality measures for colorectal cancer (CRC) screening do not assess longitudinal adherence and thus may overestimate the quality of care. Our goal was to evaluate the adherence to repeated yearly fecal occult blood tes ... Full text Link to item Cite

Colonoscopy withdrawal time and risk of neoplasia at 5 years: results from VA Cooperative Studies Program 380.

Journal Article Am J Gastroenterol · August 2010 Featured Publication OBJECTIVES: Withdrawal time (WT) has been proposed as a quality indicator for colonoscopy based on evidence that it is directly related to the rate of adenoma detection. Our objective was to test the hypothesis that baseline WT is inversely associated with ... Full text Link to item Cite

Quality of nonmetastatic colorectal cancer care in the Department of Veterans Affairs.

Journal Article J Clin Oncol · July 1, 2010 Featured Publication PURPOSE: The Veterans Affairs (VA) healthcare system treats approximately 3% of patients with cancer in the United States each year. We measured the quality of nonmetastatic colorectal cancer (CRC) care in VA as indicated by concordance with National Compr ... Full text Link to item Cite

Colorectal cancer: national and international perspective on the burden of disease and public health impact.

Journal Article Gastroenterology · June 2010 Featured Publication Colorectal cancer is a significant cause of morbidity and mortality in the United States and throughout the world. The importance of this disease to gastroenterologists cannot be understated, given that screening and surveillance colonoscopy are dominant s ... Full text Link to item Cite

Reply

Journal Article Gastroenterology · January 1, 2010 Full text Cite

Time from positive screening fecal occult blood test to colonoscopy and risk of neoplasia.

Journal Article Dig Dis Sci · November 2009 Featured Publication There is no guideline defining the optimal time from a positive screening fecal occult blood test to follow-up colonoscopy. We reviewed records of 231 consecutive primary care patients who received a colonoscopy within 18 months of a positive fecal occult ... Full text Link to item Cite

Severity of Clostridium difficile-associated diarrhea in solid organ transplant patients.

Journal Article Transpl Infect Dis · December 2007 Clostridium difficile-associated diarrhea (CDAD) has a wide spectrum of disease severity. Studies have implicated immunosuppressants as a risk factor for severe disease. We hypothesized that solid organ transplant (SOT) patients with CDAD would be at great ... Full text Link to item Cite

Direct-to-consumer advertising of pharmaceuticals.

Journal Article Am J Med · June 2007 Since the US Food and Drug Administration (FDA) released new guidelines on broadcast direct-to-consumer advertising in 1997, the prevalence of direct-to-consumer advertising of prescription drugs has increased exponentially. The impact on providers, patien ... Full text Link to item Cite

Disparity in the kinetics of onset of hypermutation in immunoglobulin heavy and light chains.

Journal Article Immunol Cell Biol · June 2000 The present paper describes a comparative analysis of light chains associated with primary and secondary IgM, as well as with secondary IgG antibodies to fluorescein, undertaken in order to explore the relationship between light chain somatic hypermutation ... Full text Link to item Cite