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Featured researches published by Ziad F. Gellad.


Gastroenterology | 2015

American Gastroenterological Association Institute Guideline on the Diagnosis and Management of Asymptomatic Neoplastic Pancreatic Cysts

Santhi Swaroop Vege; Barry Ziring; Rajeev Jain; Paul Moayyedi; Megan A. Adams; Spencer D. Dorn; Sharon Dudley-Brown; Steven L. Flamm; Ziad F. Gellad; Claudia B. Gruss; Lawrence R. Kosinski; Joseph K. Lim; Yvonne Romero; Joel H. Rubenstein; Walter E. Smalley; Shahnaz Sultan; David S. Weinberg; Yu-Xiao Yang

This article has an accompanying continuing medical education activity on page e12. Learning Objective: At the conclusion of this exercise, the learner will understand the approach to counseling patients regarding the optimal method and frequency of radiologic imaging, indications for invasive tests like endoscopic ultrasonography (EUS) and surgery, select patients for follow-up after surgery, decide the duration of such follow-up, and decide when to stop surveillance for those with and without surgery.


Gastroenterology | 2010

Colorectal Cancer: National and International Perspective on the Burden of Disease and Public Health Impact

Ziad F. Gellad; Dawn Provenzale

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 segments of clinical practice. The United States is the only country in the world where incidence and mortality rates from colorectal cancer are reported to be decreasing significantly, but health disparities in cancer screening, treatment, and survival persist. Health disparities are also evident worldwide, where the impact of this disease is staggering. In fact, rates of cancer are increasing in many parts of the world. Eliminating barriers to cancer screening and treatment could lead to substantial gains in quality and quantity of life and decrease the burden of colorectal cancer on public health. Programmatic and opportunistic screening programs have already had a measurable impact on disease burden, although the optimal screening strategy remains a matter of debate. Screening programs vary throughout the world, and further refinement will require a tailored approach because of differences in politics and fiscal reality among individual countries. Despite the strong impact of colorectal cancer on public health, there is cause for optimism and room for hope.


Gastroenterology | 2015

American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis

Neil Stollman; Walter Smalley; Ikuo Hirano; Megan A. Adams; Spencer D. Dorn; Sharon Dudley-Brown; Steven L. Flamm; Ziad F. Gellad; Claudia B. Gruss; Lawrence R. Kosinski; Joseph K. Lim; Yvonne Romero; Joel H. Rubenstein; Walter E. Smalley; Shahnaz Sultan; David S. Weinberg; Yu-Xiao Yang

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis 67 68 69 70 71 72 73 74 Neil Stollman, Walter Smalley, Ikuo Hirano, and AGA Institute Clinical Guidelines Committee


Transplant Infectious Disease | 2007

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

Ziad F. Gellad; Barbara D. Alexander; J.K. Liu; B.C. Griffith; A.M. Meyer; Jeffrey L. Johnson; Andrew J. Muir

Abstract: 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 greater risk for severe disease because of their profound immunosuppression. Adult SOT patients with CDAD seen at Duke University Medical Center between 1999 and 2003 were compared with a reference group of non‐transplant patients with CDAD. The primary outcome was the development of complicated colitis defined as death, intensive care unit admission, or urgent colectomy within 30 days of diagnosis. A secondary outcome was relapse within 60 days. Eighty transplant and 86 non‐transplant cases were reviewed. There was no significant difference in the development of complicated colitis (13.8% vs. 7.0%) or relapse rates (6.2% vs. 7.0%) between the 2 groups. In the entire sample, 18.5% of patients receiving corticosteroids unrelated to transplantation relapsed as compared with 4.5% not receiving corticosteroids (risk ratio 4.3, P=0.02). In conclusion, no significant difference was found in severity of CDAD between SOT patients and non‐transplant patients. Exposure to corticosteroids was significantly associated with an increased risk of relapse and may warrant a longer treatment course.


Gastroenterology | 2015

American Gastroenterological Association Institute Guideline on the Diagnosis and Management of Lynch Syndrome

Joel H. Rubenstein; Robert Enns; Joel J. Heidelbaugh; Alan N. Barkun; Megan A. Adams; Spencer D. Dorn; Sharon Dudley-Brown; Steven L. Flamm; Ziad F. Gellad; Claudia B. Gruss; Lawrence R. Kosinski; Joseph K. Lim; Yvonne Romero; Walter E. Smalley; Shahnaz Sultan; David S. Weinberg; Yu-Xiao Yang

Veterans Affairs Center for Clinical Management Research; Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, Michigan; Division of Gastroenterology, St Paul’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada; Departments of Family Medicine and Urology, University of Michigan Medical School, Ann Arbor, Michigan; and Division of Gastroenterology, McGill University, McGill University Health Centre, Montreal, Quebec, Canada


The American Journal of Gastroenterology | 2011

Longitudinal Adherence to Fecal Occult Blood Testing Impacts Colorectal Cancer Screening Quality

Ziad F. Gellad; Karen M. Stechuchak; Deborah A. Fisher; Maren K. Olsen; Jennifer R McDuffie; Truls Østbye; William S. Yancy

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 tests (FOBTs) in order to better understand the extent to which longitudinal adherence may impact screening quality.METHODS:This was a retrospective cohort analysis of 1,122,645 patients aged 50–75 years seen at any of the 136 Department of Veterans Affairs medical centers across the United States in 2000 and followed through 2005. The primary outcome was receipt of adequate CRC screening as defined by receipt of FOBTs in at least 4 out of 5 years or receipt of any number of FOBTs in addition to at least one colonoscopy, flexible sigmoidoscopy, or double-contrast barium enema. In a predefined subset of patients receiving exclusively FOBT, adherence with repeated testing was determined over the 5-year study period.RESULTS:Only 41.1% of men and 43.6% of women received adequate screening. Of the 384,527 men who received exclusively FOBT, 42.1% received a single FOBT, 26.0% received 2 tests, 17.8% received 3 tests, and only 14.1% were documented to have received at least 4 tests during the study period. Among the 10,469 female veterans receiving FOBT alone, rates were similar with only 13.7% completing at least 4 FOBTs in the 5-year study period.CONCLUSIONS:Adherence to repeated FOBT is low, suggesting that cross-sectional measurements of quality may overestimate the programmatic success of CRC screening.


Journal of Clinical Oncology | 2010

Quality of Nonmetastatic Colorectal Cancer Care in the Department of Veterans Affairs

George L. Jackson; L. Douglas Melton; David H. Abbott; Leah L. Zullig; Diana L. Ordin; Steven C. Grambow; Natia S. Hamilton; S. Yousuf Zafar; Ziad F. Gellad; Michael J. Kelley; Dawn Provenzale

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 Comprehensive Cancer Network practice guidelines (six indicators) and timeliness of care (three indicators). PATIENTS AND METHODS A retrospective medical record abstraction was done for 2,492 patients with incident stages I to III CRC diagnosed between October 1, 2003, and March 31, 2006, who underwent definitive CRC surgery. Patients were treated at one or more of 128 VA medical centers. The proportion of patients receiving guideline-concordant care and time intervals between care processes were calculated. RESULTS More than 80% of patients had preoperative carcinoembryonic antigen determination (ie, stages II to III disease) and documented clear surgical margins (ie, stages II to III disease). Between 72% and 80% of patients had appropriate referral to a medical oncologist (ie, stages II to III disease), preoperative computed tomography scan of the abdomen and pelvis (ie, stages II to III disease), and adjuvant fluorouracil-based chemotherapy (ie, stage III disease). Less than half of patients with stages I to III CRC (43.5%) had a follow-up colonoscopy 7 to 18 months after surgery. The mean number of days between major treatment events included the following: 26.6 days (standard deviation [SD], 38.2; median, 20 days) between diagnosis and initiation of treatment (in stages II to III disease); 64.8 [corrected] days (SD, 54.9; median, 50 days) between definitive surgery and start of adjuvant chemotherapy (in stages II to III disease); and 444.2 [corrected] days (SD, 182.1; median, 393 days) between definitive surgery and follow-up colonoscopies (in stages I to III disease). CONCLUSION Although there is opportunity for improvement in the area of cancer surveillance, the VA performs well in meeting established guidelines for diagnosis and treatment of CRC.


The American Journal of Gastroenterology | 2010

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

Ziad F. Gellad; David G. Weiss; Dennis J. Ahnen; David A. Lieberman; George L. Jackson; Dawn Provenzale

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 the risk of finding neoplasia at interval colonoscopy.METHODS:In all, 3,121 subjects, aged 50–75 years, had screening colonoscopy between 1994 and 1997 at 13 Veteran Affairs Medical Centers. In all, 1,193 subjects returned by protocol for surveillance within 5.5 years. In the 304 patients without polyps at baseline, we evaluated the contribution of baseline WT to their risk of interval neoplasia using bivariate and logistic regression analysis. We also examined the correlation between mean WT, baseline adenoma detection rate, and interval neoplasia rate at the medical-center level.RESULTS:The average WT at the baseline exam in subjects with neoplasia on follow-up was 15.3 min as compared with 13.2 min in subjects without neoplasia (P=0.18). In a logistic regression model, WT was not associated with the risk of interval neoplasia (P=0.07). At the medical-center level, mean WT was not correlated with the probability of finding interval neoplasia (P=0.61) but was positively correlated with adenoma detection rate at baseline (P=0.03).CONCLUSIONS:In this study with a mean baseline WT &12 min, there was no detectable association between WT and risk of future neoplasia. The medical center–level WT was positively correlated with adenoma detection. Therefore, above a certain threshold, WT may no longer be an adequate quality measure for screening colonoscopy.


Antiviral Therapy | 2012

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

Ziad F. Gellad; Shelby D. Reed; Andrew J. Muir

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 effects and considerable costs. Understanding the balance between costs and effectiveness is critical to making decisions about the optimal use of these new agents, especially for health care systems constrained by rising costs. Our goal for this review is to facilitate an understanding of the importance of cost-effectiveness analyses in guiding policy decisions about the use of newly approved drugs as well as future therapies for hepatitis C.


The American Journal of Gastroenterology | 2013

Clinical Practice Variation in the Management of Diminutive Colorectal Polyps: Results of a National Survey of Gastroenterologists

Ziad F. Gellad; Corrine I. Voils; Li Lin; Dawn Provenzale

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 a Web-based survey. We compared respondents and nonrespondents using demographic and practice information from the American Medical Association Physician Masterfile.RESULTS:Respondents varied in their definition of diminutive polyps. Respondents acknowledged leaving diminutive polyps in place during colonoscopy in various scenarios. Years in practice, confidence in endoscopic histologic diagnosis, and never having seen advanced histology in a diminutive polyp were predictive of leaving polyps in place. The majority of respondents were at least somewhat agreeable to leaving diminutive polyps in place if guidelines endorsed this practice.CONCLUSIONS:Gastroenterologists vary in their removal of diminutive polyps. The results have implications for the interpretation and management of variable polyp detection rates.

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