Publications

2024

Shah ED, Chan WW, Jodorkovsky D, et al. Optimizing the Management Algorithm for Heartburn in General Gastroenterology: Cost-Effectiveness and Cost-Minimization Analysis.. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024;22(10):2011-2022.e5. doi:10.1016/j.cgh.2023.08.026

BACKGROUND AND AIMS: Heartburn is the most common symptom seen in gastroenterology practice. We aimed to optimize cost-effective evaluation and management of heartburn.

METHODS: We developed a decision analytic model from insurer and patient perspectives comparing 4 strategies for patients failing empiric proton pump inhibitors (PPIs): (1) PPI optimization without testing, (2) endoscopy with PPI optimization for all patients, (3) endoscopy with PPI discontinuation when erosive findings are absent, and (4) endoscopy/ambulatory reflux monitoring with PPI discontinuation as appropriate for phenotypic management. Health outcomes were respectively defined on systematic reviews of clinical trials. Cost outcomes were defined on Centers for Medicare and Medicaid Services databases and commercial multipliers for direct healthcare costs, and national observational studies evaluating healthcare utilization. The time horizon was 1 year. All testing was performed off PPI.

RESULTS: PPI optimization without testing cost $3784/y to insurers and $3128 to patients due to lower work productivity and suboptimal symptom relief. Endoscopy with PPI optimization lowered insurer costs by $1020/y and added 11 healthy days/y by identifying erosive reflux disease. Endoscopy with PPI discontinuation added 11 additional healthy days/y by identifying patients without erosive reflux disease that did not need PPI. By optimizing phenotype-guided treatment, endoscopy/ambulatory reflux monitoring with a trial of PPI discontinuation was the most effective of all strategies (gaining 22 healthy days/y) and saved $2183 to insurers and $2396 to patients.

CONCLUSIONS: Among patients with heartburn, endoscopy with ambulatory reflux monitoring (off PPI) optimizes cost-effective management by matching treatment to phenotype. When erosive findings are absent, trialing PPI discontinuation is more cost-effective than optimizing PPI.

Leung R, Yeung MLC, Li Y, Muftah M, Chan WW, Leung WK. TEMPORAL TREND OF INCIDENCE AND PREVALENCE OF EOSINOPHILIC ESOPHAGITIS IN ASIA: A SYSTEMATIC REVIEW AND META-ANALYSIS.. The American journal of gastroenterology. Published online 2024. doi:10.14309/ajg.0000000000003096

OBJECTIVE: There are limited epidemiological studies on eosinophilic esophagitis (EoE) in Asia. We studied the temporal trend of EoE in Asia, the presenting symptoms and association with atopic diseases.

MATERIALS AND METHODS: Literature search on PubMed, Embase, MEDLINE, Scopus, and Web of Science was performed to retrieve studies published between 1980 and 2023 that reported the prevalence or incidence of EoE in Asia. We employed the random effects model to estimate the pooled incidence and prevalence. I2 index and Cochran Q test were used to assess heterogeneity. Subgroup analyses were conducted for study types, different regions, years of examination, and age groups. The proportion of atopic diseases amongst patients with EoE was described.

RESULTS: 25 studies from Asia were included. The pooled prevalence of EoE was 33.5 cases per 100,000 inhabitants in population-based studies and 11.0 cases per 1000 patients/visitors in hospital-based studies. The incidence rate among children was 12.3 cases per 1,000 patients/visitors, whereas for adults it was only 0.2 cases per 1,000 patients/visitors. Amongst population-based studies, there was an increase in prevalence from 19.8 per 100,000 in 2005-2009 to 73.0 per 100,000 in 2015-2019. Similar upward trend was observed in hospital-based studies conducted during the same time period. Patients with EoE commonly presented with dysphagia (36.3%) and nausea and vomiting (34.6%). History of atopy was reported in 57.2% of EoE patients in Asia.

CONCLUSION: The prevalence and incidence of EoE in Asia have been rising over the past decades. Due to the limited number of Asian studies and variations in subjects' sources, caution should be exercised when interpreting these results.

Hiramoto B, Flanagan R, Muftah M, Shah ED, Chan WW. Centrally Distributed Adiposity as a Modifiable Risk Factor for Fecal Incontinence: United States Population-based Analysis.. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024;22(9):1908-1916.e1. doi:10.1016/j.cgh.2024.04.002

BACKGROUND AND AIMS: Fecal incontinence (FI) is highly prevalent with substantial impacts on quality of life and health care utilization. The impact of obesity on FI remains unclear, with differing conclusions using body mass index (BMI) as a risk factor. We aimed to determine the association between obesity and FI, and whether this relationship is dependent on the distribution of adiposity (waist circumference-to-height ratio [WHtR]).

METHODS: This was a population-based analysis of the National Health and Nutrition Examination Survey, including participants who responded to the bowel health survey in 2005 to 2010. FI was defined by the accidental bowel leakage of solid stool, liquid, or mucus at least once in the past month. Stepwise multivariable logistic regression models were constructed to assess risk factors for FI.

RESULTS: A total of 7606 participants were included, with an overall FI prevalence of 9.2%. When stratified by quartiles of body measurements, FI was increasingly prevalent from the 1st to the 4th quartile for both WHtR (range, 5.3%-12.5%) and BMI (range, 7.1%-10.5%). WHtR was associated with FI and was a stronger predictor than BMI in all quartiles of body measurement. On multivariable analysis, WHtR remained a significant predictor of FI comparing the 4th with the 1st quartile of body measurements (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.11-2.80; P = .017), whereas BMI was not. A WHtR cutoff of >0.592 optimized the Youden index in prediction of FI in the overall sample.

CONCLUSION: WHtR was independently associated with increased odds of FI in this nationally representative sample of United States adults, whereas BMI was not consistently correlated. This suggests bowel continence may depend more on how body mass is distributed.

Krause AJ, Carlson DA, Chan WW, et al. High Diagnostic Yield of Abnormal Endoscopic Findings in the Evaluation of Laryngopharyngeal Reflux.. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024;22(8):1741-1743.e1. doi:10.1016/j.cgh.2024.01.012

Esophagogastroduodenoscopy (EGD) is recommended in patients with typical gastroesophageal reflux disease (GERD) symptoms (heartburn, regurgitation, chest pain) in the setting of proton pump inhibitor (PPI) nonresponse. EGD evaluates for erosive disease, assesses antireflux barrier integrity, excludes non-GERD conditions, and, in the absence of erosive findings, is followed by reflux testing.1,2 The diagnostic utility of EGD is less clear in the evaluation for laryngopharyngeal reflux (LPR), and the current reference standard is ambulatory reflux monitoring.1,3,4 This study of patients referred for evaluation of chronic laryngeal symptoms had the following aims: (1) to characterize endoscopic findings, (2) to discern whether findings differed between patients with or without concomitant esophageal reflux symptoms, and (3) to measure the association between endoscopic findings and objective GERD on ambulatory reflux monitoring.

Lo WK, Muftah M, Goldberg HJ, Sharma N, Chan WW. Concurrent abnormal non-acid reflux is associated with additional chronic rejection risk in lung transplant patients with increased acid exposure.. Diseases of the esophagus : official journal of the International Society for Diseases of the Esophagus. 2024;37(7). doi:10.1093/dote/doae020

Acid reflux has been associated with allograft injury and rejection in lung transplant patients; however, the pathogenic role of non-acid reflux remains debated. We aimed to evaluate the impact of concurrent abnormal non-acid reflux with acid reflux on chronic rejection in lung transplant patients with acid reflux. This was a retrospective cohort study of lung transplant recipients who underwent pre-transplant combined impedance-pH study off acid suppression. Only subjects with acid exposure >4% were included. Non-acid reflux (pH > 4) episodes >27 was considered abnormal per prior normative studies. Chronic rejection was defined as chronic lung allograft dysfunction (CLAD) per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses were performed using Cox proportional hazards and Kaplan-Maier methods, with censoring at death, anti-reflux surgery, or last follow-up. In total, 68 subjects (28 abnormal/40 normal non-acid reflux) met inclusion criteria for the study. Baseline demographic/clinical characteristics were similar between groups. Among this cohort of patients with increased acid exposure, subjects with concurrent abnormal non-acid reflux had significantly higher risk of CLAD than those without on Kaplan-Meier analysis (log-ranked P = 0.0269). On Cox multivariable regression analysis controlling for body mass index, age at transplantation, and proton pump inhibitor use, concurrent abnormal non-acid reflux remained independently predictive of increased CLAD risk (hazard ratio 2.31, confidence interval: 1.03-5.19, P = 0.04). Presence of concurrent abnormal non-acid reflux in lung transplant subjects with increased acid exposure is associated with additional risk of chronic rejection. Non-acid reflux may also contribute to pathogenicity in lung allograft injury/rejection, supporting a potential role for impedance-based testing in this population.

INTRODUCTION: Adenoma per colonoscopy (APC) has recently been proposed as a quality measure for colonoscopy. We evaluated the impact of a novel artificial intelligence (AI) system, compared with standard high-definition colonoscopy, for APC measurement.

METHODS: This was a US-based, multicenter, prospective randomized trial examining a novel AI detection system (EW10-EC02) that enables a real-time colorectal polyp detection enabled with the colonoscope (CAD-EYE). Eligible average-risk subjects (45 years or older) undergoing screening or surveillance colonoscopy were randomized to undergo either CAD-EYE-assisted colonoscopy (CAC) or conventional colonoscopy (CC). Modified intention-to-treat analysis was performed for all patients who completed colonoscopy with the primary outcome of APC. Secondary outcomes included positive predictive value (total number of adenomas divided by total polyps removed) and adenoma detection rate.

RESULTS: In modified intention-to-treat analysis, of 1,031 subjects (age: 59.1 ± 9.8 years; 49.9% male), 510 underwent CAC vs 523 underwent CC with no significant differences in age, gender, ethnicity, or colonoscopy indication between the 2 groups. CAC led to a significantly higher APC compared with CC: 0.99 ± 1.6 vs 0.85 ± 1.5, P = 0.02, incidence rate ratio 1.17 (1.03-1.33, P = 0.02) with no significant difference in the withdrawal time: 11.28 ± 4.59 minutes vs 10.8 ± 4.81 minutes; P = 0.11 between the 2 groups. Difference in positive predictive value of a polyp being an adenoma among CAC and CC was less than 10% threshold established: 48.6% vs 54%, 95% CI -9.56% to -1.48%. There were no significant differences in adenoma detection rate (46.9% vs 42.8%), advanced adenoma (6.5% vs 6.3%), sessile serrated lesion detection rate (12.9% vs 10.1%), and polyp detection rate (63.9% vs 59.3%) between the 2 groups. There was a higher polyp per colonoscopy with CAC compared with CC: 1.68 ± 2.1 vs 1.33 ± 1.8 (incidence rate ratio 1.27; 1.15-1.4; P < 0.01).

DISCUSSION: Use of a novel AI detection system showed to a significantly higher number of adenomas per colonoscopy compared with conventional high-definition colonoscopy without any increase in colonoscopy withdrawal time, thus supporting the use of AI-assisted colonoscopy to improve colonoscopy quality ( ClinicalTrials.gov NCT04979962).

Fernandez AM, Chan WW. Update on extraesophageal manifestations of gastroesophageal reflux.. Current opinion in gastroenterology. 2024;40(4):305-313. doi:10.1097/MOG.0000000000001037

PURPOSE OF REVIEW: Symptoms/complications related to extraesophageal reflux (EER) are increasingly prevalent presentations and pose significant challenges for clinicians. We summarize and discuss clinical advances and developments in pathophysiology, testing and treatment algorithms of upper/lower airway manifestations of EER.

RECENT FINDINGS: Growing evidence supports likely multifactorial causes of laryngeal symptoms, including EER, oropharyngeal pathologies, allergic conditions, and cognitive-affective processes (brain-larynx interaction). Diagnostic paradigm for laryngopharyngeal reflux (LPR) is shifting towards a personalized approach with noninvasive strategies/prediction tools to risk-stratify patients for upfront reflux testing over empiric acid suppression trials. Management should be multipronged to include antireflux therapies and treatments targeting other causes. Lower airway complications of EER may result in lung dysfunction and poor transplant outcomes. Esophageal symptoms are often absent and routine esophageal/reflux testing to guide timely antireflux therapies may lead to improved outcomes. Modalities that leverage impedance technology may be important, given the potential role of nonacidic reflux. Novel impedance-based metrics such as mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index may provide adjunctive diagnostic values.

SUMMARY: Standardized approach to diagnosis/management of EER should include multidisciplinary care teams and consider different phenotypes, nonreflux contributors, and the complex gut-airway relationships. Prompt antireflux therapies after careful candidate selection may improve outcomes of these airway complications.

Krause AJ, Kaizer AM, Carlson DA, et al. Validated Clinical Score to Predict Gastroesophageal Reflux in Patients With Chronic Laryngeal Symptoms: COuGH RefluX.. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024;22(6):1200-1209.e1. doi:10.1016/j.cgh.2024.01.021

BACKGROUND & AIMS: Discerning whether laryngeal symptoms result from gastroesophageal reflux is clinically challenging and a reliable tool to stratify patients is needed. We aimed to develop and validate a model to predict the likelihood of gastroesophageal reflux disease (GERD) among patients with chronic laryngeal symptoms.

METHODS: This multicenter international study collected data from adults with chronic laryngeal symptoms who underwent objective testing (upper gastrointestinal endoscopy and/or ambulatory reflux monitoring) between March 2018 and May 2023. The training phase identified a model with optimal receiver operating characteristic curves, and β coefficients informed a weighted model. The validation phase assessed performance characteristics of the weighted model.

RESULTS: A total of 856 adults, 304 in the training cohort and 552 in the validation cohort, were included. In the training phase, the optimal predictive model (area under the curve, 0.68; 95% CI, 0.62-0.74), was the Cough, Overweight/obesity, Globus, Hiatal Hernia, Regurgitation, and male seX (COuGH RefluX) score, with a lower threshold of 2.5 and an upper threshold of 5.0 to predict proven GERD. In the validation phase, the COuGH RefluX score had an area under the curve of 0.67 (95% CI, 0.62-0.71), with 79% sensitivity and 81% specificity for proven GERD.

CONCLUSIONS: The externally validated COuGH RefluX score is a clinically practical model to predict the likelihood of proven GERD. The score classifies most patients with chronic laryngeal symptoms as low/high likelihood of proven GERD, with only 38% remaining as indeterminate. Thus, the COuGH RefluX score can guide diagnostic strategies and reduce inappropriate proton pump inhibitor use or testing for patients referred for evaluation of chronic laryngeal symptoms.