SAStephen T. Amann

Stephen T. Amann

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Stephen T. Amann has a total of 136 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Resurgent Inflation and Its Impact on Medicare Reimbursements for Outpatient Gastroenterology Procedures

    by Dipen D. Patel, Stephen T. Amann, Benjamin Hart

    INTRODUCTION: Rising healthcare costs have led to decreasing reimbursements for various procedures and providers. We chose to analyze Medicare reimbursement trends for 26 esophagogastroduodenoscopy (EGD) and 31 colonoscopy current procedural terminology (CPT) codes from 2018 to 2023 for hospital outpatient centers, ambulatory surgical centers (ASC), and gastroenterologists. We also wanted to look at the effects of inflation on these Medicare reimbursements. METHODS: We calculated the nominal percentage change from 2018 to 2023 for each CPT code. We then took inflation data provided by the US Bureau of Labor Statistics and calculated the real change in reimbursements from 2018 to 2023 for each of the 31 colonoscopy and 26 EGD CPT codes. RESULTS: Our results show that although nominal reimbursements to physicians have been steadily declining for performing gastrointestinal procedures, nominal reimbursements to hospital outpatient and ASC have been increasing from 2018 to 2023. After taking into account inflation, physicians saw significant decreases in real purchasing power for performing EGD and colonoscopies. ASC and hospital outpatient centers saw reimbursements keep up with inflation. DISCUSSION: Physician reimbursements for gastroenterology procedures make up a small portion of reimbursements by Medicare compared to Medicare reimbursements to facilities such as ASC and hospital outpatient centers. However, physicians have seen significant reimbursement cuts, whereas facilities have not. Moreover, higher inflation leads to increased expenses for gastroenterology practices. It remains to be seen how these reimbursement changes will affect patients access to care and physicians practice sustainability.


  • Differences in Age at Onset of Symptoms, and Effects of Genetic Variants, in Patients With Early vs Late-Onset Idiopathic Chronic Pancreatitis in a North American Cohort

    by Michele D. Lewis, Jyothsna Talluri, C. Mel Wilcox, Judah N. Abberbock, Gong Tang, Darwin L. Conwell, Peter A. Banks, Gregory A. Cote, Stuart Sherman, Samer Alkaade, et al.


  • Increased awareness enhances physician recognition of the role of smoking in chronic pancreatitis

    by Thiruvengadam Muniraj, Dhiraj Yadav, Judah N. Abberbock, Samer Alkaade, Stephen T. Amann, Michelle A. Anderson, Peter A. Banks, Randall E. Brand, Darwin Conwell, Gregory A. Cote, et al.


  • Chronic Pancreatitis

    by Sarah J. Schwarzenberg, Aliye Uc, Bridget Zimmerman, Michael Wilschanski, C. Mel Wilcox, David C. Whitcomb, Steven L. Werlin, David Troendle, Gong Tang, Adam Slivka, et al.

    Objectives: The aim of the present study was to investigate the natural history of chronic pancreatitis (CP); patients in the North American Pancreatitis Study2 (NAPS2, adults) and INternational Study group of Pediatric Pancreatitis: In search for a cuRE (INSPPIRE, pediatric) were compared.Methods: Demographics, risk factors, disease duration, management and outcomes of 224 children and 1063 adults were compared using appropriate statistical tests for categorical and continuous variables.Results: Alcohol was a risk in 53% of adults and 1% of children (P < 0.0001); tobacco in 50% of adults and 7% of children (P < 0.0001). Obstructive factors were more common in children (29% vs 19% in adults, P = 0.001). Genetic risk factors were found more often in children. Exocrine pancreatic insufficiency was similar (children 26% vs adult 33%, P = 0.107). Diabetes was more common in adults than children (36% vs 4% respectively, P < 0.0001). Median emergency room visits, hospitalizations, and missed days of work/school were similar across the cohorts. As a secondary analysis, NAPS2 subjects with childhood onset (NAPS2‐CO) were compared with INSPPIRE subjects. These 2 cohorts were more similar than the total INSPPIRE and NAPS2 cohorts, including for genetic risk factors. The only risk factor significantly more common in the NAPS2‐CO cohort compared with the INSPPIRE cohort was alcohol (9% NAPS2‐CO vs 1% INSPPIRE cohorts, P = 0.011).Conclusions: Despite disparity in age of onset, children and adults with CP exhibit similarity in demographics, CP treatment, and pain. Differences between groups in radiographic findings and diabetes prevalence may be related to differences in risk factors associated with disease and length of time of CP.


  • Recurrent Acute Pancreatitis Significantly Reduces Quality of Life Even in the Absence of Overt Chronic Pancreatitis

    by Gregory A. Coté, Dhiraj Yadav, Judah A. Abberbock, David C. Whitcomb, Stuart Sherman, Bimaljit S. Sandhu, Michelle A. Anderson, Michele D. Lewis, Samer Alkaade, Vikesh K. Singh, et al.

    Ters (the North American Pancreatitis Studies); these included subjects with chronic pancreatitis (n= 1086), RAP alone (n= 508), and non-disease controls (n= 1025). QOL was measured using the Short Form 12 (SF-12), generating a Physical Component Summary (PCS) and the Mental Component Summary score (MCS). Multivariable regression models were developed to measure the effect of RAP on QOL, the predictors of lower QOL in those with RAP, and the differential effect QOL predictors between CP and RAP. RESULTS: Compared to controls (51.0 ± 9.4), subjects with RAP (41.1 ± 11.4) and CP (37.2 ± 11.8) had lower PCS (p< 0.01). Subjects with CP had lower PCS compared to those with RAP (p< 0.01). Similarly, MCS was lower among RAP (44.6 ± 11.5) and CP (42.8 ± 12.2) subjects compared to controls (51.7 ± 9.1,p< 0.01). Subjects with CP had lower MCS compared to those with RAP (p< 0.01). After controlling for independent predictors of PCS, RAP was associated with lower PCS (estimate -8.46,p< 0.01) and MCS (estimate -6.45,p< 0.0001) compared to controls. The effect of endocrine insufficiency on PCS was differentially greater among RAP subjects (-1.28 for CP vs. -4.9 for RAP,p= 0.0184). CONCLUSIONS: Even in the absence of CP, subjects with RAP have lower physical and mental QOL. This underscores the importance of identifying interventions to attenuate RAP before the development of overt CP....


  • Known genetic susceptibility factors for chronic pancreatitis in patients of European ancestry are rare in patients of African ancestry

    by Anna Evans Phillips, Jessica LaRusch, Phil Greer, Judah Abberbock, Samer Alkaade, Stephen T. Amann, Michelle A. Anderson, John Baillie, Peter A. Banks, Randall E. Brand, et al.


  • Patient and Disease Characteristics Associated With the Presence of Diabetes Mellitus in Adults With Chronic Pancreatitis in the United States

    by Melena D Bellin, David C Whitcomb, Judah Abberbock, Stuart Sherman, Bimaljit S Sandhu, Timothy B Gardner, Michelle A Anderson, Michele D Lewis, Samer Alkaade, Vikesh K Singh, et al.

    On of patients with CP of all etiologies enrolled in the North American Pancreatitis 2 studies. Methods: Participants (1,171) with CP (n=383 with DM,n=788 without DM) were enrolled prospectively from 26 participating centers. Questionnaires were completed by patients and physicians in a cross-sectional assessment. Patient demographics and disease characteristics were compared for CP with DM vs. without DM. Logistic regression was performed to assess the variables associated with DM diagnosis in a multivariable model. Results: Diabetics were more likely to be black (P=0.02), overweight, or obese (P<0.001), and with a family history of DM (P=0.0005). CP patients with DM were more likely to have pancreatic calcifications (63% vs. 54%,P=0.002), atrophy (44% vs. 32%,P<0.0001), and prior pancreas surgery (26.9% vs. 16.9%,P<0.0001). In multivariate logistic regression modeling, the strongest risk factors for DM were obesity (odds ratio (OR) 2.8, 95% confidence interval (CI) 1.9, 4.2) and exocrine insufficiency (OR 2.4, 95% CI 1.8, 3.2). Conclusions: In this large multicenter cohort of patients with CP, exocrine insufficiency, calcifications, and pancreas surgery conveyed higher odds of having DM. However, the traditional ‘type 2 DM’ risk factors of obesity and family history were similarly important in conveying risk for DM....


  • Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities

    by Jorge D Machicado, Stephen T Amann, Michelle A Anderson, Judah Abberbock, Stuart Sherman, Darwin L Conwell, Gregory A Cote, Vikesh K Singh, Michele D Lewis, Samer Alkaade, et al.

    Morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. Results: Mean PCS and MCS scores were 36.7±11.7 and 42.4±12.2, respectively. Significant (P<0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild–moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild–moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P<0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8–6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. Conclusions: Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses....


  • Racial Differences in the Clinical Profile, Causes, and Outcome of Chronic Pancreatitis

    by Mel C Wilcox, Bimaljit S Sandhu, Vikesh Singh, Andres Gelrud, Judah N Abberbock, Stuart Sherman, Gregory A Cote, Samer Al-Kaade, Michelle A Anderson, Timothy B Gardner, et al.

    Nts. METHODS: We analyzed data on black patients with CP prospectively enrolled in the multicenter North American Pancreatitis Studies from 26 US centers during the years 2000–2014. CP was defined by definitive evidence on imaging studies or histology. Information on demographics, etiology, risk factors, disease phenotype, treatment, and perceived effectiveness was obtained from responses to detailed questionnaires completed by both patients and physicians. RESULTS: Of the 1,159 patients enrolled, 248 (21%) were black. When compared with whites, blacks were significantly more likely to be male (60.9 vs. 53%), ever (88.2 vs. 71.8%), or current smokers (64.2 vs. 45.9%), or have a physician-defined alcohol etiology (77 vs. 41.9%). There was no overall difference in the duration of CP although for alcoholic CP, blacks had a longer duration of disease (8.6 vs. 6.97 years;P=0.02). Blacks were also significantly more likely to have advanced changes on pancreatic morphology (calcifications (63.3 vs. 55.2%), atrophy (43.2 vs. 34.6%), pancreatic ductal stricture or dilatation (72.6 vs. 65.5%) or common bile duct stricture (18.6 vs. 8.2%)) and function (endocrine insufficiency 39.9 vs. 30.2%). Moreover, the prevalence of any (94.7 vs. 83%), constant (62.6 vs. 51%), and severe (78.4 vs. 65.8%) pain and disability (35.1 vs. 21.4%) were significantly higher in blacks. Observed differences were in part related to variances in etiology and duration of disease. No differences in medical or endoscopic treatments were seen between races although prior cholecystectomy (31.1 vs. 19%) was more common in white patients. CONCLUSIONS: Differences were observed between blacks and whites in the underlying cause, morphologic expression, and pain characteristics of CP, which in part are explained by the underlying risk factor(s) with alcohol and tobacco being much more frequent in black patients as well as disease duration....