Karna Dev Bardhan

Do we need a new gastro-oesophageal reflux disease questionnaire?

Background : Gastro‐oesophageal reflux disease (GERD) is highly prevalent in Western countries. Because the majority of patients do not present with endoscopic abnormalities, the assessment of the symptom severity and quality of life, and their response to treatment, has become increasingly important. Self‐assessed symptom questionnaires are now key instruments in clinicaltrials.

Evaluation of GERD Symptoms during Therapy. Part I

Background/Aims: The changes in gastroesophageal reflux disease (GERD)-related symptoms on treatment are variously described, but currently available questionnaires have shortcomings. We therefore developed a self-assessment reflux questionnaire (ReQuestTM). This article describes the process of development and testing. Materials and Methods: For the first version of ReQuestTM the symptom spectrum of GERD and the various symptom descriptions were investigated. The 67 identified symptom descriptions were condensed empirically into 6 dimensions, to which a 7th dimension on general well-being was added. The symptom burden of the dimensions was measured by frequency and/or intensity. ReQuestTM was translated into different languages and then tested in focus groups. The initial validation was based on data from a clinical trial of patients with erosive GERD, treated with pantoprazole 20 or 40 mg daily for 28 days. Factor analyses determined the contribution of each symptom to the different dimensions. Additionally, correlation analyses between the identified factors and the dimensions were performed. Results: On the basis of factor analyses, ReQuestTM was reduced to a 60-item scale. The factors generated correlated strongly with the dimensions and confirmed the empirical process mathematically. Conclusion: ReQuestTM provides a valuable, self-assessment tool for evaluating the daily treatment response in patients with erosive GERD.

Reflux Revisited: Advancing the Role of Pepsin

Gastroesophageal reflux disease is mediated principally by acid. Today, we recognise reflux reaches beyond the esophagus, where pepsin, not acid, causes damage. Extraesophageal reflux occurs both as liquid and probably aerosol, the latter with a further reach. Pepsin is stable up to pH 7 and regains activity after reacidification. The enzyme adheres to laryngeal cells, depletes its defences, and causes further damage internally after its endocytosis. Extraesophageal reflux can today be detected by recognising pharyngeal acidification using a miniaturised pH probe and by the identification of pepsin in saliva and in exhaled breath condensate by a rapid, sensitive, and specific immunoassay. Proton pump inhibitors do not help the majority with extraesophageal reflux but specifically formulated alginates, which sieve pepsin, give benefit. These new insights may lead to the development of novel drugs that dramatically reduce pepsinogen secretion, block the effects of adherent pepsin, and give corresponding clinical benefit. “For now we see through a glass, darkly.” —First epistle, Chapter 13, Corinthians

Fibroblast growth factor 19 in patients with bile acid diarrhoea: a prospective comparison of FGF19 serum assay and SeHCAT retention

Bile acid diarrhoea is a common, under‐diagnosed cause of chronic watery diarrhoea, responding to specific treatment with bile acid sequestrants. We previously showed patients with bile acid diarrhoea have lower median levels compared with healthy controls, of the ileal hormone fibroblast growth factor 19 (FGF19), which regulates bile acid synthesis.

Evaluation of GERD symptoms during therapy. Part II. Psychometric evaluation and validation of the new questionnaire ReQuest in erosive GERD.

Background/Aims: Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest™). This publication describes the psychometric evaluation and validation of ReQuest™. Methods: This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest™. The psychometric analyses of ReQuest™ included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. Results: Validation of ReQuest™ indicated very high internal consistency (Cronbach’s α = 0.90) and test-retest reliability (intraclass correlation coefficient 0.94 (long-long) and 0.86 (short-short)). This was also the case for the two subscales ReQuest™-GI and ReQuest™-WSO with Cronbach’s α coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of >0.8 at day 28. Construct validity was good. Conclusion: ReQuest™ is a highly reliable, valid and responsive self-assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.

Intermittent and on-demand use of proton pump inhibitors in the management of symptomatic gastroesophageal reflux disease

The epidemic of gastroesophageal reflux disease (GERD) in industrialized nations is currently spreading to less-developed ones, with more than half of the patients having symptomatic or mild erosive GERD. The long-term management of GERD has been dominated by daily maintenance treatment with proton pump inhibitors (PPI) to prevent relapse. It is common, however, for many patients with mild disease and infrequent symptom relapses to use a PPI only when symptoms demand. Patients with symptomatic or mild erosive GERD are therefore ideal for on-demand or intermittent treatment. The efficacy of such a strategy of intermittent treatment, or treatment of symptoms on demand, has recently been evaluated in four randomized controlled studies. These trials demonstrate that such therapeutic strategies reduce symptoms, improve quality of life, and are cost effective. In clinical practice, the author has found these treatment strategies suitable for approximately 60% of newly diagnosed patients with GERD for the long-term management of symptomatic GERD of mild or moderate severity.

International validation of ReQuest in patients with endoscopy-negative gastro-oesophageal reflux disease.

Background : Reflux Questionnaire (ReQuest), a newly developed gastro‐oesophageal reflux disease‐sensitive scale, can be used to reliably evaluate the effect of treatment on gastro‐oesophageal reflux disease symptoms.

Development and application of a new electronic nose instrument for the detection of colorectal cancer

Colorectal cancer is a leading cause of cancer death in the USA and Europe with symptoms that mimick other far more common lower gastrointestinal (GI) disorders. This difficulty in separating colorectal cancer from these other diseases has driven researchers to search for an effective, non-invasive screening technique. Current state-of-the-art method of Faecal Immunochemical Testing achieving sensitivity ~90%, unfortunately the take-up in the western world is low due to the low patient acceptability of stool samples. However, a wide range of cancers have been distinguished from each-other and healthy controls by detecting the gas/volatile content emanating patient biological media. Dysbiosis afforded by certain disease states may be expressed in the volatile content of urine - a reflection of the gut bacterias metabolic processes. A new electronic nose instrument was developed at the University of Warwick to measure the gas/volatile content of urine headspace, based on an array of 13 commercial electro-chemical and optical sensors. An experimental setup was arranged for a cohort of 92 urine samples from patients of colorectal cancer (CRC), irritable bowel syndrome (IBS) and controls to be run through the machine. Features were extracted from response data and used in Linear Discriminant Analysis (LDA) plots, including a full 3-disease classification and one focussing on distinguishing CRC from IBS. The latter case was tested by the success of re-classification using an (n-1) K-nearest neighbour algorithm, showing 78% sensitivity and 79% specificity to CRC.

Detection of Colorectal Cancer (CRC) by Urinary Volatile Organic Compound Analysis

Colorectal cancer (CRC) is a leading cause of cancer related death in Europe and the USA. There is no universally accepted effective non-invasive screening test for CRC. Guaiac based faecal occult blood (gFOB) testing has largely been superseded by Faecal Immunochemical testing (FIT), but sensitivity still remains poor. The uptake of population based FOBt testing in the UK is also low at around 50%. The detection of volatile organic compounds (VOCs) signature(s) for many cancer subtypes is receiving increasing interest using a variety of gas phase analytical instruments. One such example is FAIMS (Field Asymmetric Ion Mobility Spectrometer). FAIMS is able to identify Inflammatory Bowel disease (IBD) patients by analysing shifts in VOCs patterns in both urine and faeces. This study extends this concept to determine whether CRC patients can be identified through non-invasive analysis of urine, using FAIMS. 133 patients were recruited; 83 CRC patients and 50 healthy controls. Urine was collected at the time of CRC diagnosis and headspace analysis undertaken using a FAIMS instrument (Owlstone, Lonestar, UK). Data was processed using Fisher Discriminant Analysis (FDA) after feature extraction from the raw data. FAIMS analyses demonstrated that the VOC profiles of CRC patients were tightly clustered and could be distinguished from healthy controls. Sensitivity and specificity for CRC detection with FAIMS were 88% and 60% respectively. This study suggests that VOC signatures emanating from urine can be detected in patients with CRC using ion mobility spectroscopy technology (FAIMS) with potential as a novel screening tool.

The construction of a new evaluative GERD questionnaire - methods and state of the art.

Gastroesophageal reflux disease (GERD) is one of the most prevalent diseases worldwide, and it is becoming increasingly important to monitor the effect of various interventions on GERD symptoms. There can be rapid temporal changes in the severity and frequency of patients’ symptoms as well as their health status and well-being, all of which could, theoretically, be monitored using diaries or questionnaires. However, current GERD monitoring instruments are not appropriate because they do not assess symptoms daily, they are not sufficiently responsive to short-term changes in health status or they are not adequately validated. To address these problems, the conceptual and psychometric requirements for a GERD symptom assessment questionnaire were identified. A dimension-based scale was designed to reduce the number of symptoms monitored on a daily basis, and the validation process was defined to produce parallel long and short forms of a scale for patients’ self-assessment of their GERD symptom response to therapy. These basic principles which underlie the successful development of a new, self-assessed symptomatic reflux questionnaire (ReQuest™) are also applicable to the development of validated questionnaires for daily symptom self- assessment in other disease areas.