Patient self-assessment of test-day symptoms in 24-h pH-metry for suspected gastroesophageal reflux disease

Systematic review: symptom assessment using patient-reported outcomes in gastroesophageal reflux disease and dyspepsia

OBJECTIVE

The importance of symptom assessment using patient-reported outcomes (PROs) is becoming increasingly recognized in the management of upper gastrointestinal (GI) disease. The authors aimed to review systematically the methodological aspects of PRO instrument development and use in the GERD or dyspepsia literature, and to assess these instruments' properties in light of the Food and Drug Administration's (FDA) guidance.

MATERIAL AND METHODS

Systematic PubMed and Embase searches (using terms based on the FDA guidance) identified studies that reported methodological aspects in developing or using PRO instruments for GERD or dyspepsia symptom measurement.

RESULTS

Ten studies were identified (six systematically and four from citation lists). Studies reported the development or use of a relevant PRO instrument, with a focus on methodological aspects that the FDA guidance describes as important for patient understanding. Studies demonstrated heterogeneity of recall periods, symptoms and response options. Two studies demonstrated that a lack of consistent vocabulary may contribute to discrepancy in symptom reporting between investigators and patients. Two studies indicated that symptoms must be described in a manner that is relevant to patients. One study described the development of a PRO instrument separately in two languages, acknowledging linguistic and cultural differences between populations. One study demonstrated changes in symptom severity based on the recall period.

CONCLUSIONS

There is considerable heterogeneity in the methodology used to develop PRO instruments for upper GI disease. Adherence to best practices in PRO development and validation may improve the quality and utility of these measures, leading to improved communication in clinical practice.

Patient Compliance during 24-Hour Dual pH Probe Monitoring for Extraesophageal Reflux

Objective. During ambulatory 24-hour dual pH probe monitoring for suspected extraesophageal reflux (EER), patients are responsible for indicating relevant study events. Study interpretation relies on patient accuracy and compliance to test instructions. This study sought to explore patient compliance during pH probe monitoring and evaluated the utility of a Post-Evaluation Questionnaire as a clinical tool. Participants and Methods. Participants were prospectively studied during 24-hour dual pH probe monitoring. Participants used both a food diary and monitor settings to indicate relevant study events. Following pH testing, participants completed a Post-Evaluation Questionnaire regarding test experiences. Results. Eighty-two participants completed the study. Means and standard deviations were calculated for individual responses on the Post-Evaluation Questionnaire. Means indicate high participant accuracy for study events, and adherence to typical activities and diet over the testing period. Factor analysis was performed on the Post-Evaluation Questionnaire items and identified two factors: “typical experiences” and “times forgot.” Cronbach's alpha demonstrated acceptable reliability levels for questions related to “typical experiences,” but poor reliability for “times forgot” questions. Conclusions. Assessment of participant compliance during pH probe testing can quickly and easily be completed through a Post-Evaluation Questionnaire. Participant compliance can be assessed for improved study interpretation.

Inter-observer agreement for multichannel intraluminal impedance-pH testing

Twenty-four-hour ambulatory multichannel intraluminal impedance (MII)-pH detects both acid and nonacid reflux (NAR). A computer-based program (Autoscan™, Sandhill Scientific, Highlands Ranch, CO, USA) automates the detection of reflux episodes, increasing the ease of study interpretation. Inter-observer agreement between multiple reviewers and with Autoscan™ for the evaluation of significant NAR with MII-pH has not been studied in the adult population. Twenty MII-pH studies on patients taking a proton pump inhibitor twice daily were randomly selected. Autoscan™ analyzed all studies using the same pre-programmed parameters. Four reviewers interpreted the MII-pH studies, adding or deleting reflux episodes detected by Autoscan™. Positive studies for NAR and total reflux episodes were based on published criteria. Cohen's kappa statistic (κ) evaluated inter-observer agreement between reviewers and Autoscan™ analysis. The average κ for pathologic NAR between reviewers was 0.57 (0.47-0.70), and between reviewers and Autoscan™ was 0.56 (0.4-0.8). When using the total reflux episode number as a marker for pathologic reflux (acid and NAR), the κ score was 0.72 (0.61-0.89) between reviewers, and 0.74 (0.53-0.9) when evaluating total reflux episodes. Two reviewers agreed more often with each other and with Autoscan™ on the number of NAR episodes, while the other two reviewers agreed with each other, but did not agree with either Autoscan™ or the first two reviewers. Inter-observer agreement between reviewers and Autoscan™ for detecting pathologic NAR is moderate, with reviewers either excluding more of the Autoscan™-defined events or excluding fewer events and therefore agreeing with Autoscan™.

Oesophageal acid hypersensitivity is not a contraindication to Nissen fundoplication

BACKGROUND

The Rome III criteria classify patients with a positive relationship between symptoms and reflux episodes but a physiological oesophageal acid exposure time as having gastro-oesophageal reflux disease (GORD) with an acid hypersensitive oesophagus. The long-term outcome of antireflux surgery in these patients was investigated.

METHODS

Outcomes of Nissen fundoplication in 28 patients with GORD refractory to proton-pump inhibitors (PPIs) and oesophageal acid hypersensitivity (group 1) were compared with those of 126 patients with pathological acid exposure (group 2).

RESULTS

Fundoplication had a similar effect in both groups. Three months after surgery, total acid exposure time and the prevalence of oesophagitis had decreased, whereas mean lower oesophageal pressure had increased. The percentage of patients using PPIs was reduced from 83 to 4 per cent in group 1 and from 86.1 to 7.4 per cent in group 2 (both P < 0.001). Quality of life measured on a scale from 0 to 100 improved from 52 to 69 (P = 0.009) and 64 (P < 0.001) respectively. The percentage of patients with resolved or improved symptoms at 5 years was similar.

CONCLUSION

Patients with oesophageal acid hypersensitivity benefit from Nissen fundoplication as much as those with pathological acid exposure.

Optimal recall periods for patient-reported outcomes: challenges and potential solutions

OBJECTIVES

As the role and importance of patient-reported outcomes (PROs) increase, the validity and reliability of PRO measures come under greater scientific and regulatory scrutiny. One key issue is selecting the 'most appropriate' recall period for capturing PROs in clinical trials. This paper draws on survey research, health-specific literature, and results from clinical trials to summarize factors that can influence recall and provide guidance on selecting an optimal recall period.

METHODS

We conducted a systematic review of six databases and additional literature drawn from bibliographies of the selected articles.

RESULTS

Six major factors can influence recall; these can be classified into two broad areas: characteristics of the recalled phenomenon (recency, attributes, complexity) and context or meaning of the recalled phenomenon (salience, patient experience, mood). Results of different recall periods for three classes of PROs are presented: health behaviors, symptoms, and health-related quality of life. We present findings on the effect of alternative recall periods for three commonly used PROs. Finally, we propose a heuristic model to link the concept under investigation with an optimal recall period.

CONCLUSIONS

No single recall period is best for all measures or all phenomena. The recall period must correspond to the characteristics of the phenomenon of interest and the purpose of the assessment. Recall period is an issue of internal validity. An incorrect recall period introduces measurement error that may reduce the chances of detecting a treatment effect. Researchers should consider recall period as seriously as they do other measurement properties.

Oesophageal pH monitoring using the Bravo catheter-free radio capsule

OBJECTIVES

Oesophageal pH monitoring is the current standard for the diagnosis of gastro-oesophageal reflux disease. The Bravo capsule allows 48-h monitoring without the need for a naso-oesophageal catheter. Our aim was to assess the Bravo capsule in terms of patient discomfort and interference with daily activities, and to determine if 48-h Bravo pH studies facilitate the diagnosis of gastro-oesophageal reflux disease.

METHODS

Ambulatory pH studies were performed at two hospitals using either the Bravo capsule (n=100) or a conventional naso-oesophageal catheter (n=100). Participants were selected either for investigation of symptoms suggestive of gastro-oesophageal reflux disease, or to follow-up antireflux surgery. All participants completed questionnaires to assess discomfort and interference with daily activities.

RESULTS

Eighty-nine Bravo studies recorded at least 48 h of data, and 95 were diagnostic. Bravo participants reported significantly less discomfort during insertion (P<0.0001) and monitoring (P<0.0001), and less interference with daily activities (P<0.0001), eating (P<0.005), sleeping (P<0.0001) and work (P<0.0001). No significant difference was observed between day 1 and 2 median total time pH<4 (4.0 and 4.3%, P=0.64), erect time pH<4 (5.0 and 5.0%, P=0.56), supine time pH<4 (0.5 and 0.5%, P=0.23), and Johnson-DeMeester scores (15.9 and 16.2, P=0.90). Ten Bravo participants (10%) were diagnosed with gastro-oesophageal reflux disease using day 2 data after a normal day 1.

CONCLUSIONS

The Bravo capsule significantly reduces the patient discomfort and interference with normal daily activities during pH monitoring associated with a naso-oesophageal catheter. Moreover, 48-h Bravo studies offer an advantage over conventional 24-h studies in diagnosing gastro-oesophageal reflux disease.

Review article: the role of acid suppression in patients with non-erosive reflux disease or functional heartburn

When patients with the typical reflux symptoms of heartburn, regurgitation, or both, undergo endoscopy, up to 75% will not have endoscopic oesophagitis or evidence of Barrett's oesophagus. These patients have been described as having endoscopic negative or, more commonly, non-erosive reflux disease (NERD). Patients without oesophagitis, but with a positive pH test, can be diagnosed with gastro-oesophageal reflux disease (GERD). Some experts also consider a response to proton pump inhibitor therapy as proof of GERD in a patient with the correct symptoms and a negative endoscopy. Patients with normal acid exposure, but who report symptoms with a majority of their reflux episodes documented during an ambulatory pH study, have also been considered to have NERD, although others have labelled them as having 'functional heartburn'. Finally, there are some patients who have reflux symptoms and respond to reflux therapy, but have no demonstrable reflux by either endoscopy or ambulatory reflux testing. Whether these patients are part of the GERD spectrum or have another diagnosis is not clear. It seems that the most widely used definition of functional disease (the Rome II criteria) would include these patients as having functional heartburn, as it was defined as 'greater than or equal to 12 weeks of either continuous or intermittent symptoms of burning retrosternal discomfort or pain without pathologic GERD, achalasia, or other motility disorders with a recognized pathologic basis'. This article reviews potential differences in pathophysiology between erosive oesophagitis and NERD; explores whether symptoms can help distinguish NERD patients from erosive oesophagitis patients; and explores the evaluation and therapy of these patients.

Catheter-based pH monitoring: use in evaluation of gastroesophageal reflux disease symptoms (on and off therapy)

Tube-based ambulatory pH testing has rapidly evolved in the past 3 decades to become the standard by which other diagnostic approaches to gastroesophageal reflux disease are judged. Acid exposure 5 cm above the manometrically determined lower esophageal sphincter is the standard for documentation of pathologic acid exposure of the distal esophagus. Proximal esophageal or hypopharyngeal monitoring is an evolving technique that may shed light on patients with supraesophageal symptoms. The ability to simultaneously monitor esophageal and gastric acidity (usually in patients with persistent symptoms despite therapy) is another advantage of this technique. Whether the new system that allows simultaneous pH and impedance monitoring and the system that uses an implantable tubeless monitoring capsule will supplant this older but well-established technology remains to be determined.

Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease

Guidelines for the diagnosis and treatment of gastroesophageal reflux disease (GERD) were published in 1995 and updated in 1999. These and other guidelines undergo periodic review. Advances continue to be made in the area of GERD, leading us to review and revise previous guideline statements. GERD is defined as symptoms or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus. These guidelines were developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee, and approved by the Board of Trustees. Diagnostic guidelines address empiric therapy and the use of endoscopy, ambulatory reflux monitoring, and esophageal manometry in GERD. Treatment guidelines address the role of lifestyle changes, patient directed (OTC) therapy, acid suppression, promotility therapy, maintenance therapy, antireflux surgery, and endoscopic therapy in GERD. Finally, there is a discussion of the rare patient with refractory GERD and a list of areas in need of additional study.

Patient predictions correlate with actual CD4+ lymphocyte and HIV-1 viral load changes in an urban, HIV-infected clinic population

Patients who were undergoing CD4+ lymphocyte and HIV-1 viral load measurement as part of their routine clinical care were asked to predict the results of these tests compared to their last recorded CD4+ lymphocyte and HIV-1 viral load measurements. One hundred eight patients predicted the results of 240 CD4+ lymphocyte and 244 viral load measurements. Both Spearman bivariate correlation and a generalized estimating equation repeated measures analysis demonstrated a significant correlation between patient-predicted and actual laboratory values for both tests. Patients with a history of depression were less likely to predict their test results correctly than patients without such a history.

The classification of oesophageal 24 h pH measurements using a Kohonen self-organizing feature map

Analysis of 24 h oesophageal pH studies can be problematic with many patients asymptomatic during the investigation, despite observations of reflux. The aim of this study was to carry out a cluster analysis of ambulatory pH studies to determine any underlying patterns and classes within the data. The results of 900 24 h pH studies were investigated using the Kohonen self-organizing feature map (SOFM), a neural network that can be used to identify clusters within multidimensional data. The clinical features were presented to the network and the main classes identified. The SOFM-based analysis showed that patients clinically assessed as having symptomatic reflux during the study could be described by four major classifications. The results also showed that the probability of identifying a correlation between symptoms and reflux during an investigation varies from 0.49 to 0.78 for the classes identified. The developed network may be a useful tool in the classification of pH data. The cluster-based technique may offer an alternative to standard statistical techniques for high-dimensional gastrointestinal data and form the basis of an expert system for the automated analysis of pH data.