Optimizing the Management Algorithm for Heartburn in General Gastroenterology: Cost-Effectiveness and Cost-Minimization Analysis

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.

Percutaneous Closure of Post-Infarct Left Ventricular Pseudoaneurysm; A Review of Literature

Left ventricular pseudoaneurysm is a well-known complication of myocardial infarction and open-heart surgery and has recently been described as succeeding transapical transcatheter aortic valve replacement (TAVR). While surgical intervention is the conventional therapeutic approach, transcatheter closure can be considered in patients at high risk for surgical procedures. In this article, we present a post-myocardial infarction pseudoaneurysm for which closure was done via retrograde left ventricular (LV) access using an Amplatzer Septal Occluder, and provide a review of recent literature focusing on indications and outcomes of the different percutaneous techniques and devices.

Diagnostic accuracy of assays using point-of-care testing or dried blood spot samples for the determination of HCV RNA: a systematic review

BACKGROUND

Fingerstick point-of-care and dried-blood-spot (DBS) HCV RNA testing increases testing uptake and linkage to care. This systematic review evaluated the diagnostic accuracy of point-of-care testing and DBS to detect HCV RNA.

METHODS

Bibliographic databases and conference presentations were searched for eligible studies. Meta-analysis was used to pool estimates.

RESULTS

Of 359 articles identified, 43 studies were eligible and included. When comparing the Xpert HCV Viral Load Fingerstick assay to venous blood samples (7 studies with 987 samples), the sensitivity and specificity for HCV RNA detection was 99% (95% CI:98%-100%) and 99% (95% CI:96%-100%) and for HCV RNA quantification was 100% (95% CI:93%-100%) and 100% (95% CI:94%-100%). The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing was 6% (95% CI:3%-11%). When comparing DBS to venous blood samples (28 studies with 3988 samples), the sensitivity and specificity for HCV RNA detection was 97% (95% CI:95%-98%) and 100% (95% CI:98%-100%) and for HCV RNA quantification was 98% (95% CI:96%-99%) and 100% (95% CI:95%-100%).

CONCLUSION

Excellent diagnostic accuracy was observed across assays for detection of HCV RNA from fingerstick and DBS samples. The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing highlights the importance of operator training and quality assurance programs.

A simple framework to identify optimal cost-effective risk thresholds for a single screen: Comparison to Decision Curve Analysis

Decision Curve Analysis (DCA) is a popular approach for assessing biomarkers and risk models, but does not require costs and thus cannot identify optimal risk thresholds for actions. Full decision analyses can identify optimal thresholds, but typically used methods are complex and often difficult to understand. We develop a simple framework to calculate the Incremental Net Benefit for a single-time screen as a function of costs (for tests and treatments) and effectiveness (life-years gained). We provide simple expressions for the optimal cost-effective risk-threshold and, equally importantly, for the monetary value of life-years gained associated with the risk-threshold. We consider the controversy over the risk-threshold to screen women for mutations in BRCA1/2. Importantly, most, and sometimes even all, of the thresholds identified by DCA are infeasible based on their associated dollars per life-year gained. Our simple framework facilitates sensitivity analyses to cost and effectiveness parameters. The proposed approach estimates optimal risk thresholds in a simple and transparent manner, provides intuition about which quantities are critical, and may serve as a bridge between DCA and a full decision analysis.

Retrospective Detection of SARS-CoV-2 in Symptomatic Patients prior to Widespread Diagnostic Testing in Southern California

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused one of the worst pandemics in recent history. Few reports have revealed that SARS-CoV-2 was spreading in the United States as early as the end of January. In this study, we aimed to determine if SARS-CoV-2 had been circulating in the Los Angeles (LA) area at a time when access to diagnostic testing for coronavirus disease 2019 (COVID-19) was severely limited.

Methods

We used a pooling strategy to look for SARS-CoV-2 in remnant respiratory samples submitted for regular respiratory pathogen testing from symptomatic patients from November 2019 to early March 2020. We then performed sequencing on the positive samples.

Results

We detected SARS-CoV-2 in 7 specimens from 6 patients, dating back to mid-January. The earliest positive patient, with a sample collected on January 13, 2020 had no relevant travel history but did have a sibling with similar symptoms. Sequencing of these SARS-CoV-2 genomes revealed that the virus was introduced into the LA area from both domestic and international sources as early as January.

Conclusions

We present strong evidence of community spread of SARS-CoV-2 in the LA area well before widespread diagnostic testing was being performed in early 2020. These genomic data demonstrate that SARS-CoV-2 was being introduced into Los Angeles County from both international and domestic sources in January 2020.

Computer assisted Doppler waveform analysis and ultrasound derived turbulence intensity ratios can predict early hyperplasia development in newly created vascular access fistula: Pilot study, methodology and analysis

Objectives

Following surgical creation of arterio-venous fistulae (AVF), the desired outward remodeling is often accompanied by the development of neointimal hyperplasia (NIH), which can stymie maturation and may lead to thrombosis and access failure. The aim of this study was to investigate the feasibility of using a non-invasive test, to detect and quantify the turbulent flow patterns believed to be associated with NIH development.

Design

This was a prospective, observational study. Ultrasound derived turbulence intensity ratios (USTIR) were calculated from spectral Doppler waveforms, recorded from newly formed AVF, and were compared with haemodynamic and structural changes observed during the initial maturation period.

Setting

Measurements were obtained by accredited Clinical Vascular Scientists, at the Royal Free Hospital, London.

Participants

Patients with newly created AVF were invited to participate in the study. A total of 30 patients were initially recruited with 19 participants completing the 10 week study protocol.

Outcome measures

The primary outcome measure was the development of NIH resulting in a haemodynamically significant lesion.The secondary outcome was successful maturation of the AVF at 10 weeks.

Results

Elevated USTIR in the efferent vein 2 weeks post surgery corresponded to the development of NIH formation (P = 0.02). A cut off of 6.39% predicted NIH development with a sensitivity of 87.5% and a specificity of 80%.

Conclusion

Analysis of Doppler waveforms can successfully identify deleterious flow patterns and predict inward luminal remodelling in maturing AVF. We propose a longitudinal follow up study to assess the viability of this technique as a surveillance tool.

Capitalism is groovy, but at what cost?

Due to the COVID-19 pandemic, the FDA was forced to bypass normal protocol and issue Emergency Use Authorization for diagnostic testing. As a result, we have seen an explosion in the number of available molecular diagnostic tests developed by various private enterprises. Our case reports of an 85-year-old female who was suffering from a multitude of co-morbidities and underwent three different molecular diagnostic tests in a short timeframe. With little data on the precision and reliability of the multiple available tests, it has become extremely difficult to diagnose and guide management. Instead of focusing on commercial ventures, FDA in conjunction with the CDC should prioritize our resources to tackle COVID-19 as a public health crisis.

Esophageal Mucosal Impedance Patterns Discriminate Patients With Eosinophilic Esophagitis From Patients With GERD

BACKGROUND & AIMS

It is a challenge to make a diagnosis of eosinophilic esophagitis (EoE) because its symptoms and histologic features overlap with those of gastroesophageal reflux disease (GERD). A minimally invasive device was recently developed to detect mucosal impedance (MI) that measures epithelial integrity during upper endoscopy. We aimed to quantify MI along the esophagus and identify patterns that differentiated patients with and without GERD from those with EoE, and determine whether MI values and patterns are sufficient to identify patients with EoE using histologic findings as a reference.

METHODS

We performed a retrospective analysis of 91 patients with upper gastrointestinal symptoms referred for diagnostic testing for GERD and EoE from 2012 through 2014 (discovery set). During the first endoscopy, MI measurements were obtained at 2, 5, and 10 cm from the squamocolumnar junction. GERD was confirmed by ambulatory pH tests, and histologic analyses of biopsies were used to confirm EoE. We then used statistical modeling to identify MI patterns along the esophagus (at 10 cm, 5 cm, and 2 cm) that associated with GERD vs EoE. We validated our findings in a prospective cohort of 49 patients undergoing elective upper endoscopy for dysphagia, from 2015 through 2016, testing the ability of MI patterns to identify patients with vs. without EoE.

RESULTS

We found patients with EoE to have a unique MI pattern, with low values along the esophageal axis. MI measurements at 5 cm could discern patients with normal vs abnormal mucosa with 83% sensitivity and 79% specificity, and patients with EoE vs GERD with 84% sensitivity and 70% specificity; these measurements differentiated the patient populations with the highest level of accuracy of any of the 6 measurements tested. In the validation study, a rater using the esophageal MI pattern identified patients with EoE with 100% sensitivity and 96% specificity.

CONCLUSION

We identified and validated a pattern of MI along the esophagus that can identify patients with EoE vs normal mucosa or GERD with high levels of sensitivity.

Individualizing Cancer Screening Recommendations: A Team-Based Learning Activity for Fourth-Year Medical Students

INTRODUCTION

Cancer screenings are key preventive services that patients receive in primary care. Health care professional students are generally taught about major society guidelines and U.S. Preventive Services Task Force recommendations for cancer screenings. Unfortunately, students and novice providers may view these influential recommendations as a rule book by which to provide care. Experienced providers recognize that not every patient fits neatly into clinical guidelines. Appropriate use of cancer screening entails an understanding of patient preferences, patient-specific health factors, and screening risks and associated pitfalls.

METHODS

This 2-hour team-based learning (TBL) session immerses learners in three challenging patient scenarios that are designed to stimulate nuanced discussion of cancer screening using controversial cases. The scenarios encompass the following cases: (1) a 68-year-old man actively seeking prostate cancer screening, (2) a heavy smoker with psychiatric illness and alcoholism being considered for lung cancer screening, and (3) a 42-year-old woman seeking to become pregnant who inquires about breast cancer screening.

RESULTS

The materials were originally designed for fourth-year students on an ambulatory medicine rotation. Our students universally viewed this activity as a high-quality presentation applicable to their careers. They strongly agreed that the cases facilitated a deeper understanding of the nuances of cancer screening.

DISCUSSION

This TBL encourages learners to critically appraise cancer screening guidelines and apply them to real-life examples. It is applicable for learners who understand the complexities of patient care but still suffer from a guidelines-are-rules mentality.

Chronic Diarrhea: Diagnosis and Management

Chronic diarrhea is a common problem affecting up to 5% of the population at a given time. Patients vary in their definition of diarrhea, citing loose stool consistency, increased frequency, urgency of bowel movements, or incontinence as key symptoms. Physicians have used increased frequency of defecation or increased stool weight as major criteria and distinguish acute diarrhea, often due to self-limited, acute infections, from chronic diarrhea, which has a broader differential diagnosis, by duration of symptoms; 4 weeks is a frequently used cutoff. Symptom clusters and settings can be used to assess the likelihood of particular causes of diarrhea. Irritable bowel syndrome can be distinguished from some other causes of chronic diarrhea by the presence of pain that peaks before defecation, is relieved by defecation, and is associated with changes in stool form or frequency (Rome criteria). Patients with chronic diarrhea usually need some evaluation, but history and physical examination may be sufficient to direct therapy in some. For example, diet, medications, and surgery or radiation therapy can be important causes of chronic diarrhea that can be suspected on the basis of history alone. Testing is indicated when alarm features are present, when there is no obvious cause evident, or the differential diagnosis needs further delineation. Testing of blood and stool, endoscopy, imaging studies, histology, and physiological testing all have roles to play but are not all needed in every patient. Categorizing patients after limited testing may allow more directed testing and more rapid diagnosis. Empiric antidiarrheal therapy can be used to mitigate symptoms in most patients for whom a specific treatment is not available.

Penile sonoelastography for the localization of a non-palpable, non-sonographically visualized lesion in a patient with penile curvature from Peyronie's disease

INTRODUCTION

Sonoelastography is an emerging ultrasound-based technique that allows characterization of tissue stiffness.

AIM

The aim of this report is to present a case of significant penile curvature with a non-palpable, non-sonographically visualized plaque that was demonstrable with sonoelastography.

METHODS

A 60-year-old male presented with significant left penile curvature during erections. The penis was evaluated with physical exam followed by B-mode and color Doppler ultrasound. No evidence of plaque was identified with these modalities. Shear wave sonoelastography was pursued to further characterize the patient's Peyronie's disease.

RESULTS

An area of increased tissue stiffness that correlated with the site of maximum curvature was identified with shear wave sonoelastography and used to target intralesional injection therapy.

CONCLUSION

Sonoelastography provides an additional way to characterize, localize, and deliver therapy to a lesion in patients with Peyronie's disease and is particularly useful when palpation and B-mode ultrasonography have failed to demonstrate a plaque.

Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling

The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves.