Development of a digestive health status instrument: tests of scaling assumptions, structure and reliability in a primary care population

Unsupervised machine learning highlights the challenges of subtyping disorders of gut-brain interaction

BACKGROUND

Unsupervised machine learning describes a collection of powerful techniques that seek to identify hidden patterns in unlabeled data. These techniques can be broadly categorized into dimension reduction, which transforms and combines the original set of measurements to simplify data, and cluster analysis, which seeks to group subjects based on some measure of similarity. Unsupervised machine learning can be used to explore alternative subtyping of disorders of gut-brain interaction (DGBI) compared to the existing gastrointestinal symptom-based definitions of Rome IV.

PURPOSE

This present review aims to familiarize the reader with fundamental concepts of unsupervised machine learning using accessible definitions and provide a critical summary of their application to the evaluation of DGBI subtyping. By considering the overlap between Rome IV clinical definitions and identified clusters, along with clinical and physiological insights, this paper speculates on the possible implications for DGBI. Also considered are algorithmic developments in the unsupervised machine learning community that may help leverage increasingly available omics data to explore biologically informed definitions. Unsupervised machine learning challenges the modern subtyping of DGBI and, with the necessary clinical validation, has the potential to enhance future iterations of the Rome criteria to identify more homogeneous, diagnosable, and treatable patient populations.

Patient-Reported Outcomes in Disorders of Gut-Brain Interaction

Disorders of gut-brain interaction are characterized by chronic gastrointestinal symptoms in the absence of abnormal endoscopic or radiologic findings or objective biomarkers that can be identified during routine clinical evaluation. The assessment of the symptom pattern and severity, therefore, is the key modality to evaluate the presence, impact, and evolution of these conditions, for both clinical and regulatory purposes. Patient-reported outcomes are structured symptom assessment questionnaires designed to evaluate symptom patterns, quantify severity of symptoms, and evaluate response to treatment at follow-up. This review provides an overview of currently available patient-reported outcomes for evaluating the main disorders of gut-brain interaction, specifically, functional dyspepsia; irritable bowel syndrome; and chronic constipation. It summarizes their content, level of validation for clinical practice and for research, and the regulatory approach to these conditions. Expected future developments and need for further research on patient-reported outcomes for these and other disorders of gut-brain interaction are highlighted.

Patient-reported outcome measures in functional dyspepsia: a systematic review and COSMIN analysis

BACKGROUND

Functional dyspepsia (FD) as a type of disorders of brain-gut interaction (DBGI), patient self-reporting of its symptoms becomes an important component of clinical outcome assessment. We performed a systematic review using Consensus Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines to identify the best available patient-reported outcome measure (PROM) of FD.

METHODS

The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched four databases with no date limit, looking for previously confirmed PROMs for evaluating FD symptoms. An overall rating was then assigned based upon COSMIN guidelines, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the level of evidence for psychometric properties of included PROMs.

RESULTS

Thirty articles covering outcome indicators of 24 patient reports were included. The Leuven Postprandial Distress Scale (LPDS) showed adequate content validity and moderate quality evidence of adequate internal consistency to generate an A recommendation.

CONCLUSION

LPDS is currently the most recommended PROM for patient self-reported FD symptoms. However, it fails to assess two important areas of cross-cultural validity/ measurement invariance and measurement error. Future research can be continuously improved on this basis.

Development and Validation of the Chronic Gastritis Scale Under the System of Quality of Life Instruments for Chronic Diseases QLICD-CG Based on Classical Test Theory and Generalizability Theory

BACKGROUND AND AIM

Quality of life (QOL) for patients with chronic gastritis (CG) is of interest worldwide and disease-specific instruments are needed for clinical research and practice. This paper focused on the development and validation of the CG scale under the system of Quality of Life Instruments for Chronic Diseases (QLICD-CG) by the modular approach and both classical test theory and generalizability theory.

METHODS

The QLICD-CG was developed based on programmed decision procedures including multiple nominal and focus group discussions, in-depth interviews and quantitative statistical procedures. Based on the data measuring QOL 3 times before and after treatments from 142 inpatients with CG, the psychometric properties of the scale were evaluated with respect to validity, reliability and responsiveness employing correlation analysis, multi-trait scaling analysis, factor analyses, t tests and also G studies and D studies of generalizability theory analysis.

RESULTS

Correlation, multi-trait scaling and factor analyses confirmed good construct validity and criterion-related validity when using SF-36 as a criterion. The internal consistency α for all domains were higher than 0.70 except for the social domain (0.62). Test-retest reliability coefficients (Pearson r and intraclass correlations) for the overall score and all domains were higher than 0.80 except for the social domain (0.77), while they were ranging between 0.72 to 0.94 at facets level; The overall score and scores for all domains/facets had statistically significant changes (P<0.01) after treatments except for facets of social effects and sexual function with standardized response mean ranging from 0.04 to 1.03, but from 0.34 to 1.03 for the domain level scores. G-coefficients and index of dependability (Ф coefficients) confirmed the reliability of the scale further with more exact variance components, and decision information on number of items changing.

CONCLUSIONS

The QLICD-CG could be used as a useful instrument in assessing QoL for patients with CG, with good psychometric properties including validity, reliability and responsiveness and also several advantages.

Clostridium difficile Infection-Daily Symptoms (CDI-DaySyms™) questionnaire: psychometric characteristics and responder thresholds

Background

The purpose of the current study was to determine the final content validation, psychometric characteristics, clinically meaningful improvement, and responder thresholds of the Clostridium difficile infection (CDI)–Daily Symptoms (CDI-DaySyms™) patient-reported outcome (PRO) questionnaire.

Methods

This validation study was part of two phase III studies (NCT01987895 and NCT01983683) conducted in patients with mild-to-moderate or severe CDI who completed the CDI-DaySyms™ daily throughout the treatment period. The questionnaire was evaluated in three stages: final PRO item content validation (Stage I); psychometric evaluation of reliability and construct validity (Stage II); and determination of clinically meaningful improvement and responder thresholds using distribution-based methods (Stage III).

Results

The analysis included 168 patients. Most patients were female and Caucasian with mild-to-moderate CDI. The mean age was 57.1 years. Initial item analysis supported by confirmatory factor analysis demonstrated the relevance of 10 items grouped into three distinct domains (Diarrhea Symptoms, Abdominal Symptoms, and Systemic/Other Symptoms). Domain scores demonstrated acceptable internal consistency and test-retest reliability, were sensitive to change, and correlated in expected directions with other relevant symptom and disease-severity measures. Responder thresholds were defined as score changes of − 1.00, − 0.80, and − 0.70 in the Diarrhea Symptoms, Abdominal Symptoms, and Systemic/Other Symptoms domains, respectively.

Conclusions

The CDI-DaySyms™ is a valid measure of patient-reported CDI symptoms, with good measurement properties, which supports its utility as an endpoint in clinical studies. Further studies confirming responder thresholds based on anchor-based methods are required.

Trial registration

NCT01987895, registered November 20, 2013; NCT01983683, registered November 14, 2013.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1142-9) contains supplementary material, which is available to authorized users.

Differentiation of functional gastrointestinal disorders from healthy volunteers by lactulose hydrogen breath test and test meal

BACKGROUND AND AIM

Functional dyspepsia (FD) is a common disorder of gut-brain interaction with incompletely understood pathophysiology. Consequently, heterogeneous expert opinions on diagnostic tests and assessment of treatment efficacies exist. So far, no consensus about the most relevant diagnostic and outcome tool has been reached. In this study, we aimed to analyze the significance of a combined lactulose hydrogen breath test (LHBT) and liquid meal, yet representing a standardized test in irritable bowel syndrome (IBS), in FD.

METHODS

We analyzed data of 146 FD, 204 IBS patients, and 50 healthy volunteers (HV). All patients underwent LHBT with a meal-drink consisting of 30-g Lactulose and 400-mL Ensure®. Effect of abdominal symptom generation in FD/IBS compared with HV was assessed on a patient-reported Likert-scale.

RESULTS

There was a significant difference between FD/IBS patients and HV in LHBT-induced abdominal pain (odds ratio [OR] 246.9, 95% confidence interval [CI] 26.6-2290.7; OR 161.2, 95% CI 16.9-1534.8), abdominal bloating (OR 384.8, 95% CI 92.9-2135.4; OR 524.1, 95% CI 114.7-3432.3), borborygmi (OR 9.9, 95% CI 2.2-46.9; OR 17.7, 95% CI 4.7-67.4), nausea only in FD (OR 174.4, 95% CI 15.5-5375.5), and diarrhea in IBS only (OR 25.8, 95% CI 2.0-7012.6). Hydrogen production was not significantly different in FD/IBS and HV.

CONCLUSIONS

In this study, we demonstrated significant differences in postprandial symptom generation in FD and IBS compared with HV after LHBT. This does not only allow us to discriminate FD/IBS from HV but may also represent a diagnostic and monitoring tool for FD/IBS in the future, including monitoring of treatment effects.

The CDI-DaySyms: Content Development of a New Patient-Reported Outcome Questionnaire for Symptoms of Clostridium difficile Infection

OBJECTIVES

To develop a patient-reported outcome (PRO) questionnaire for symptoms of Clostridium difficile infection (CDI) following the US Food and Drug Administration PRO guidelines.

METHODS

Patients' experiences of CDI symptoms were elicited in open-ended discussions with patients and nurses at five US sites (stage 1). A draft PRO measure was developed after demonstration of concept saturation. Two rounds of cognitive interviews were conducted with patients at three US sites (stage 2), with revision of the draft measure after each round. All patients were 18 years or older, with confirmed CDI. The study was conducted with input from a panel of five CDI experts in Europe and North America.

RESULTS

Stage 1 included interviews with 18 patients and supplementary interviews with 6 nurses; 16 additional patients were interviewed in stage 2. Patients were representative of the general CDI population and were diverse in age, sex, and disease severity. Concept saturation was reached in stage 1. Items were organized in a draft conceptual framework with five hypothesized domains: diarrhea, abdominal discomfort, tiredness, lightheadedness, and other symptoms. Stage 2 demonstrated initial content validity of the 13-item draft daily diary (CDI-DaySyms). Participants reported that the questions were clear, relevant, and comprehensive. They were able to use the instructions to complete the diary correctly and considered the 24-hour recall period appropriate.

CONCLUSIONS

The CDI-DaySyms captures symptoms relevant to patients undergoing CDI, demonstrating initial content validity. Final content and psychometric validity are being evaluated in a substudy comprising patients from two ongoing international clinical trials (ClinicalTrials.gov identifiers NCT01987895 and NCT01983683).

Systematic review: Disease-specific instruments to assess gastrointestinal symptoms in functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with incompletely understood pathophysiology and heterogeneous symptom presentation. Assessment of treatment efficacy in FD is a methodological challenge as response to treatment must be assessed primarily by measuring subjective symptoms. Therefore, the use of patient-reported outcome measures (PROMs) is recommended by regulatory authorities to assess gastrointestinal symptoms in clinical trials for FD. In the last decades, a multitude of outcome measures has been developed. However, currently no PROM has been approved by the regulatory authorities, and no consensus has been reached with regard to the most relevant outcome measure in FD.

PURPOSE

This systematic review discusses the available disease-specific outcome measures for assessment of FD symptoms with psychometric validation properties, strengths, and limitations. Moreover, recommendations for use of current available outcome measures are provided, and potential areas of future research are discussed.

Effects of saxagliptin added to sub-maximal doses of metformin compared with uptitration of metformin in type 2 diabetes: the PROMPT study

OBJECTIVE

The PROMPT study compared efficacy and tolerability of two treatment intensification strategies: adding saxagliptin or uptitrating metformin monotherapy, in patients with type 2 diabetes (T2D) and inadequate glycaemic control on a sub-maximal metformin dose.

RESEARCH DESIGN AND METHODS

In this double-blind, 24-week study, metformin-tolerant patients with T2D on metformin monotherapy were randomised to receive fixed-dose metformin 1500 mg/day, plus either add-on saxagliptin 5 mg/day (SAXA-MET) or a two-step metformin uptitration (MET-UP) to a maximum dose (2500 mg/day).

CLINICAL TRIAL REGISTRATION

NCT01006590.

MAIN OUTCOME MEASURES

Primary: absolute change from baseline in glycated haemoglobin A(1c) (HbA(1c)) (Week 24). Secondary: proportion of patients achieving a therapeutic glycaemic response (Week 24); change from baseline in fasting plasma glucose (Week 24); safety and tolerability. Exploratory analyses comprised three patient-related questionnaires, including the validated 5-dimension Digestive Health Status Index (DHSI).

RESULTS

A total of 286 patients were randomised: (SAXA-MET: 147; MET-UP: 139). Baseline mean (SD) HbA(1c): 7.71 (0.85; SAXA-MET); 7.80 (0.82; MET-UP). Adjusted mean reductions from baseline in HbA(1c) (Week 24): -0.47% (SAXA-MET); -0.38% (MET-UP); mean (95% CI) difference in treatment effect, -0.10% (-0.26, 0.07); p = 0.260. The proportion of patients (95% CI) achieving a therapeutic glycaemic response (HbA(1c) < 7%): 43.8% (34.8, 49.6) (SAXA-MET) vs. 35.0% (29.0, 43.8) (MET-UP). Of the five DHSI domains, mean (95% CI) differences were observed for diarrhoea-predominant score (+0.8 [-2.5, 4.0] vs. +7.9 [4.6, 11.2]) and dysmotility score (-0.5 [-2.0, 1.0] vs. +1.9 [0.3, 3.4]), (SAXA-MET and MET-UP, respectively). The most common adverse event was diarrhoea: 6.1% (SAXA-MET) vs. 12.2% (MET-UP).

CONCLUSIONS

In metformin-tolerant patients with T2D (inadequately controlled on sub-maximal metformin monotherapy), saxagliptin was well tolerated. Although HbA(1c) reduction was not significantly different between treatment groups, the lower occurrence of gastrointestinal symptoms in the SAXA-MET group suggests that saxagliptin add-on treatment may be a suitable alternative treatment strategy to metformin uptitration.

Validation of the UCLA Scleroderma Clinica Trial Gastrointestinal Tract Instrument version 2.0 for systemic sclerosis

OBJECTIVE

The University of California at Los Angeles (UCLA) Scleroderma Clinical Trial Consortium GI Tract Instrument (UCLA SCTC GITI) was recently developed to measure gastrointestinal tract disease in systemic sclerosis (SSc). Our study assesses the internal consistency and validity of the instrument in a different population than was used in the original study.

METHODS

A sample of 113 consecutive patients with SSc from the Canadian Scleroderma Research Group (CSRG) Registry completed the UCLA SCTC GITI, a self-administered questionnaire with 7 scales and an overall score. Reliability was evaluated using Cronbach's alpha coefficient and validity was determined by testing multiple constructs.

RESULTS

Our subjects were slightly older than the original cohort, and had less formal education and less diffuse cutaneous disease. The overall score of the instrument correlated well with the GI scale of the Health Assessment Questionnaire for the Spondyloarthropathies (GI-S-HAQ; r = 0.58, p < 0.001) and the total number of GI symptoms (r = 0.77, p < 0.001). Each subscale correlated well with the GI-S-HAQ. The individual scales and the overall score were able to differentiate between categorical groupings of the GI-S-HAQ. The scale scores differentiated well those patients with clinical involvement of the corresponding GI problem. Multiple linear regression adjusting for age, disease duration, sex, and ethnicity showed that the UCLA SCTC GITI had a significant association with both the physical component summary and the mental component summary of the Medical Outcomes Study Short-Form 36 questionnaire.

CONCLUSION

Our study confirms that the UCLA SCTC GITI version 2.0 will be a useful tool for assessing the role of GI involvement in SSc, even in a population with substantially different characteristics than the subjects originally tested.

A systematic review of adherence, treatment satisfaction and costs, in fixed-dose combination regimens in type 2 diabetes

OBJECTIVE

Oral antidiabetics have comparable safety and efficacy when used as fixed-dose combination therapies (FDCT) or loose-pill combination therapies (LPCT) for patients with T2DM. To evaluate alternative outcomes to safety and efficacy with FDCT, a systematic review of literature was conducted.

METHODS

Searches of Medline/Embase databases from 1998 to 2009 used predefined terms: 'fixed-dose combination', 'loose-dose combination' and 'diabetes'. Abstracts were reviewed from ISPOR, ADA, and EASD meetings (1998-2009). T2DM studies reporting adherence, patient-reported outcomes, costs, resource use or cost effectiveness were included.

RESULTS

Seventeen studies met the search criteria. Seven studies reported adherence. Adherence was 10-13% higher for FDCT than LPCT in patients starting combination therapy. Adherence decreased 1.5% and 10.0% when switching from monotherapy to combination therapy for FDCT and LPCT respectively (p < 0.001). Switching to FDCT increased adherence 3.5%-12.4%, while remaining on LPCT changed adherence -1.5% to 5.0% (p < 0.005). For patients newly initiating OAD medication, one study found no adherence advantage for FDCT compared with monotherapy or LPCT. Five RCTs reported treatment satisfaction. Four publications reported patients preferred FDCT using the Diabetes Treatment Satisfaction Questionnaire (DTSQ). One publication reported improved satisfaction for one DTSQ subscale. Five abstracts reported economic outcomes. Two abstracts determined patients on FDCT used fewer healthcare resources and had decreased direct monthly healthcare costs versus LPCT. Two cost-effectiveness analyses determined clinical benefits from clinical trials translate into cost savings and increased life expectancy. One budget impact model reported minimal budget impact.

LIMITATIONS

(1) There was limited published literature identified in this review. (2) FDCT are oral medications; these findings may only be relevant to those individuals taking an oral antidiabetic therapy. (3) Publication and reporting biases may exist.

CONCLUSIONS

The published literature suggested that T2DM patients treated with FDCT may have better adherence, improved satisfaction, and lower direct medical costs, compared to those treated with LPCT.

Questionnaire based gastroesophageal reflux disease (GERD) assessment scales

Questionnaire based assessment scales for gastroesophageal reflux disease (GERD) have been utilized for assessment of the patient's symptomatology, assessment of symptom severity and frequency, assessment of health-related quality of life and for assessment of response to treatment. A multitude of unidimensional and multidimensional questionnaires exist for making symptom assessment and monitoring quality of life in GERD. Many of the scales meet some of the parameters of an ideal evaluative GERD specific assessment instrument. Yet, there are certain shortcomings and challenges which are faced in development of GERD questionnaires. This review discusses the features of an ideal symptom assessment instrument, examines the strengths and weaknesses of currently available questionnaires.

A validation study of the Italian Short-Form Leeds Dyspepsia Questionnaire

Assessment of symptoms should be one of the main outcome measures in dyspepsia clinical trials. This requires a reliable, valid and responsive questionnaire that measures the frequency and severity of dyspeptic symptoms. The Short-Form Leeds Dyspepsia Questionnaire (SF-LDQ) has been proven to fulfil these criteria in its original version in the English language. The aim of the study was to assess the internal consistency, reliability, validity and responsiveness of the Italian version of the SF-LDQ in primary and secondary care. Unselected primary and secondary care patients completed the Italian version of the SF-LDQ. Test-retest reliability was assessed after 2 days. Validity was measured by comparison with diagnosis made by physicians. Responsiveness was determined before and after treatment for endoscopically proven disease. The SF-LDQ was administered to 311 patients in primary care and 179 in secondary care patients. Internal consistency, as judged by the Cronbach's α, was 0.90. Pearson's correlation coefficient for test-retest reliability was 0.92. The SF-LDQ had a sensitivity of 80% and a specificity of 82%. A highly significant response to change was also observed (p = 0.001). The Italian SF-LDQ is a reliable, valid and responsive self-completed outcome measure for quantifying the frequency and severity of dyspeptic symptoms.

Comparison of a composite symptom score assessing both symptom frequency and severity with a score that assesses frequency alone: a preliminary study to develop a practical symptom score to detect gastro-oesophageal reflux disease in a resource-poor setting

BACKGROUND

There is a need for a practical instrument to screen for gastro-oesophageal reflux disease (GORD) in epidemiological studies.

OBJECTIVES

To develop a practical score to detect GORD and compare assessment of both symptom frequency and severity with frequency alone.

METHODS

One hundred patients with upper gastrointestinal symptoms and 150 volunteers with no such past history faced an interviewer-administered questionnaire assessing seven symptoms, graded for frequency and severity. Two scores were generated. Score 1, the sum of frequency of symptoms and score 2, the sum of products of frequency and severity of each. Internal consistency, test-retest reliability and criterion validity against 24-h pH monitoring were assessed. Cut-off scores were generated by receiver operating characteristic curves using scores of half the volunteers and patients selected randomly and validated on the other half.

RESULTS

Cut-off scores and area under the curve for score 1 were >/=10.5 and 0.93, and score 2 were >/=12.5 and 0.93, respectively. The sensitivity and specificity of diagnosing the disease in the remaining participants using score 1 was 89.7 and 92.4% and score 2 was 93.8 and 94.0%, respectively. The instrument had good internal consistency (Cronbach alpha = 0.73) and reliability (intraclass correlation coefficient of scores 1 and 2 were 0.94 and 0.95, respectively). Score 2 showed better correlation with 24-h pH monitoring parameters (Spearman's rank correlation, P = 0.01).

CONCLUSION

Our score is valid, reliable and can detect GORD with high sensitivity and specificity. A score assessing both frequency and severity of symptoms correlates better to an objective measure of GORD.

Quality of life measures in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder with significant morbidity, resulting from the interaction of physiologic, psychological, social, cultural and behavioral factors. In view of this complex interaction, and in the absence of a measurable biological index of disease, health-related quality of life (HRQoL) has emerged as an ideal measure for use in clinical trials and outcome studies. This article discusses the relevance of HRQoL measurement in IBS and its definition. It then explores the research methodology in HRQoL and describes how global measures and generic HRQoL instruments have been used in IBS. Finally, the IBS-specific HRQoL measures are described in detail, with an emphasis on their development, content and validation.

Reliability and validity of the University of California, Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument

OBJECTIVE

To refine the previously developed scleroderma (systemic sclerosis [SSc]) gastrointestinal tract (GIT) instrument (SSC-GIT 1.0).

METHODS

We administered the SSC-GIT 1.0 and the Short Form 36 to 152 patients with SSc; 1 item was added to the SSC-GIT 1.0 to assess rectal incontinence. In addition, subjects completed a rating of the severity of their GIT involvement (from very mild to very severe). Evaluation of psychometric properties included internal consistency reliability, test-retest reliability (mean time interval 1.1 weeks), and multitrait scaling analysis.

RESULTS

Study participants were mostly women (84%) and white (81%); 55% had diffuse SSc. Self-rated severity of GIT involvement ranged from no symptoms to very mild (39%), mild (21%), moderate (31%), and severe/very severe (9%). Of an initial 53 items in the SSC-GIT 1.0, 19 items were excluded, leaving a 34-item revised instrument (the University of California, Los Angeles Scleroderma Clinical Trial Consortium GIT 2.0 [UCLA SCTC GIT 2.0]). Analyses supported 7 multi-item scales: reflux, distention/bloating, diarrhea, fecal soilage, constipation, emotional well-being, and social functioning. Test-retest reliability estimates were >/=0.68 and coefficient alphas were >/=0.67. Participants who rated their GIT disease as mild had lower scores on a 0-3 scale on all 7 scales. Symptom scales were also able to discriminate subjects with corresponding clinical GIT diagnoses. The Total GIT Score, developed by averaging 6 of 7 scales (excluding constipation), was reliable and provided greater discrimination between mild, moderate, and severe self-rated GIT involvement than individual scales.

CONCLUSION

This study provides support for the reliability and validity of the UCLA SCTC GIT 2.0, an improvement over the SSC-GIT 1.0, and supports a Total GIT Score in SSc patients with GIT.

Dysautonomia rating scales in Parkinson's disease: sialorrhea, dysphagia, and constipation--critique and recommendations by movement disorders task force on rating scales for Parkinson's disease

Upper and lower gastrointestinal dysautonomia symptoms (GIDS)--sialorrhea, dysphagia, and constipation are common in Parkinson's disease (PD) and often socially as well as physically disabling for patients. Available invasive quantitative measures for assessing these symptoms and their response to therapy are time-consuming, require specialized equipment, can cause patient discomfort and present patients with risk. The Movement Disorders Society commissioned a task force to assess available clinical rating scales, critique their clinimetric properties, and make recommendations regarding their clinical utility. Six clinical researchers and a biostatistician systematically searched the literature for scales of sialorrhea, dysphagia, and constipation, evaluated the scales' previous use, performance parameters, and quality of validation data (if available). A scale was designated "Recommended" if the scale was used in clinical studies beyond the group that developed it, has been specifically used in PD reports, and clinimetric studies have established that it is a valid, reliable, and sensitive. "Suggested" scales met at least part of the above criteria, but fell short of meeting all. Based on the systematic review, scales for individual symptoms of sialorrhea, dysphagia, and constipation were identified along with three global scales that include these symptoms in the context of assessing dysautonomia or nonmotor symptoms. Three sialorrhea scales met criteria for Suggested: Drooling Severity and Frequency Scale (DSFS), Drooling Rating Scale, and Sialorrhea Clinical Scale for PD (SCS-PD). Two dysphagia scales, the Swallowing Disturbance Questionnaire (SDQ) and Dysphagia-Specific Quality of Life (SWAL-QOL), met criteria for Suggested. Although Rome III constipation module is widely accepted in the gastroenterology community, and the earlier version from the Rome II criteria has been used in a single study of PD patients, neither met criteria for Suggested or Recommended. Among the global scales, the Scales for Outcomes in PD-Autonomic (SCOPA-AUT) and Nonmotor Symptoms Questionnaire for PD (NMSQuest) both met criteria for Recommended, and the Nonmotor Symptoms Scale (NMSS) met criteria for Suggested; however, none specifically focuses on the target gastrointestinal symptoms (sialorrhea, dysphagia, and constipation) of this report. A very small number of rating scales have been applied to studies of gastrointestinal-related dysautonomia in PD. Only two scales met "Recommended" criteria and neither focuses specifically on the symptoms of sialorrhea, dysphagia, and constipation. Further scale testing in PD among the scales that focus on these symptoms is warranted, and no new scales are needed until the available scales are fully tested clinimetrically.

Impairment of health-related quality of life in functional dyspepsia and chronic liver disease: the influence of depression and anxiety

BACKGROUND

Health-related quality of life (HRQOL) is a marker of disease severity. Data on the relative impairment of HRQOL in chronic liver disease (CLD) and functional gastrointestinal disorders are lacking and no studies have assessed the link between impairment of HRQOL and psychosocial factors yet.

AIM

To assess predictors for, and the impairment of, HRQOL in CLD and FD.

METHODS

In 181 functional dyspepsia (FD) patients, 204 CLD patients and 337 healthy blood donors, HRQOL was assessed with the Short Form-36 (mental and physical component), and anxiety and depression utilizing the Hospital Anxiety and Depression Scale.

RESULTS

Compared with HC, HRQOL is significantly lower in FD and CLD (P-value for all <0.001). The mental but not physical component of HRQOL was significantly more impaired in FD compared with CLD (P < 0.05). After adjusting for confounders, impairment of mental (P < 0.001) and physical (P = 0.005) component of HRQOL was associated with the severity of CLD and FD. In FD, the multivariate analysis revealed depression and severity of symptoms as the most important predictors of HRQOL (R2 = 21.9 and 7.1). In CLD, the mental component of HRQOL was associated with depression and anxiety (R(2) = 9.9 and 9.7).

CONCLUSIONS

In tertiary care, HRQOL is more severely impaired in FD compared with CLD. Co-morbid psychiatric conditions significantly contribute to the impairment of HRQOL.

The influence of co-morbid IBS and psychological distress on outcomes and quality of life following PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

A subset of patients with gastro-oesophageal reflux disease (GERD) does not achieve complete symptom resolution with proton pump inhibitor (PPI) therapy. The factors which affect response to PPI therapy in GERD patients remain unclear.

AIMS

To determine the prevalence and impact of irritable bowel syndrome (IBS) and psychological distress (PD) on GERD symptoms and disease-specific quality of life (QoL) before and after PPI therapy and to assess the same outcomes before and after PPI therapy in non-erosive reflux disease (NERD) and erosive oesophagitis (EO) GERD patients.

METHODS

Patients undergoing oesophago-gastroduodenoscopy (OGD) for heartburn were recruited. Participants completed validated surveys: Digestive Health Symptom Index, Reflux Disease Questionnaire, Quality of Life in Reflux and Dyspepsia and Brief Symptom Inventory (BSI). IBS was defined as >3 Manning criteria and PD as BSI score >63. At OGD, patients were classified as NERD or EO. Patients were treated with rabeprazole 20 mg/day for 8 weeks before completing follow-up surveys.

RESULTS

Of 132 GERD patients enrolled, 101 completed the study. The prevalence rates of IBS and PD were 36% and 41%, respectively. IBS independently predicted worse QoL before and after PPI therapy. PD independently predicted worse GERD symptoms and QoL before and after PPI therapy. There were no differences in symptoms or QoL between NERD and EO patients before or after PPI therapy.

CONCLUSIONS

IBS and PD impacted GERD symptoms and QoL before and after PPI therapy. Symptoms and QoL before and after PPI therapy were similar in NERD and EO patients.

The constipation severity instrument: a validated measure

PURPOSE

This study was designed to develop and test the validity and reliability of the Constipation Severity Instrument.

METHODS

Scale development was conducted in two stages: 1) 74 items were generated through a literature review and focus groups of constipated patients and medical providers; and 2) a preliminary instrument was administered to 191 constipated patients and 103 healthy volunteers. Test-retest reliability of the constipated group was assessed (N=90). Content, convergent, divergent, and discriminant validity were evaluated by using other validated measures by performing one-way analysis of variance and Pearson correlations.

RESULTS

Exploratory and confirmatory factor analysis revealed three subscales: obstructive defecation, colonic inertia, and pain. Internal consistency (alpha=0.88-0.91) and test-retest reliability (intraclass correlation coefficients=0.84-0.91) were high for all subscales. Constipated patients were grouped by Rome II criteria: functional constipation (22 percent), pelvic floor dyssynergia (15 percent), constipation predominant irritable bowel syndrome (23 percent), and no specific criteria (40 percent). Those with constipation predominant irritable bowel syndrome or pelvic floor dyssynergia scored higher on the Obstructive Defecation and Colonic Inertia subscales than those with functional constipation or no specific criteria (P=0.001-0.058). Subjects with functional constipation had much lower scores on the pain subscale than constipation predominant irritable bowel syndrome, functional constipation, or no specific criteria (P<0.009). The Constipation Severity Instrument subscale and total score correlated very highly with the subscales and total score of the Patient Assessment of Constipation Symptom measure. The Constipation Severity Instrument subscales discriminated well between constipated patients and healthy volunteers (P<0.001) and demonstrated excellent divergent validity. Higher Constipation Severity Instrument scores inversely correlated with general quality of life.

CONCLUSIONS

The Constipation Severity Instrument is a reliable and valid instrument for assessing constipated patients. Administration of the Constipation Severity Instrument to other constipated patients will further validate its use.

Development of a preliminary scleroderma gastrointestinal tract 1.0 quality of life instrument

OBJECTIVE

Gastrointestinal tract (GIT) involvement occurs in approximately 90% of patients with systemic sclerosis (SSc) and has a major impact on health-related quality of life (HRQOL). We developed an HRQOL instrument for persons with SSc.

METHODS

The Scleroderma Gastrointestinal Tract 1.0 (SSC-GIT 1.0) survey was developed after an extensive literature search, solicitation and consideration of experts' opinions, and 2 focus groups of 16 subjects with SSc and GIT involvement. A 75-item, self-reported measure assessing bowel involvement, emotional well-being, and social functioning was administered to subjects with SSc and GIT involvement. Also, subjects completed the Short Form 36 and rated the severity of their GIT symptoms (very mild to very severe), and items were transformed linearly to a scale with a possible range of 0 (worse health) to 100 (better health). Evaluation of psychometric properties included internal consistency reliability, test-retest reliability (1.3-week median time interval), multitrait scaling analysis, and exploratory factor analysis.

RESULTS

Study participants (n = 88) were primarily female (95.5%), white (79.3%), and had a mean age of 52.4 years. Self-rated severity of GIT involvement ranged from very mild or mild (36.0%) to moderate (44.0%) to severe or very severe (20.0%). Of 75 items, 23 had low item-total correlations (</=0.39) and were excluded, leaving a 52-item instrument. Analyses supported 6 multi-item HRQOL scales: reflux/indigestion, diarrhea, constipation, pain, emotional well-being, and social functioning. Test-retest reliability estimates ranged 0.69-0.90 and Cronbach's alpha ranged 0.69-0.93. Participants who rated their GIT disease as mild had the highest scores (better health) on all 6 scales; participants who rated their GIT as severe had the lowest scores (poor health).

CONCLUSION

The results support the reliability and validity of the SSC-GIT 1.0 as a measure of SSc GIT involvement. Further research is needed to examine the ability to detect change over time and define minimally important differences.

Applying data mining techniques in the development of a diagnostics questionnaire for GERD

Gastroesophageal reflux disease (GERD) is a common condition, managed mostly in primary care practice. Heartburn and acid regurgitation are considered primary symptoms, and are usually highly specific. However, the symptom spectrum is much wider and in many cases it is difficult to determine whether the patient has GERD or dyspepsia from another origin. The aim of this study is to develop a symptom score and rule for the diagnosis of GERD, using data mining techniques, to provide a clinical diagnostic tool for primary care practitioners in the evaluation and management of upper gastrointestinal symptoms. A diagnostic symptom questionnaire consisting of 15 items and based on the current literature was designed to measure the presence and severity of reflux and dyspepsia symptoms using a 5-point Likert-type scale. A total of 132 subjects with uninvestigated upper abdominal symptoms were prospectively recruited for symptom evaluation. All patients were interviewed and examined, underwent upper gastrointestinal endoscopy, and completed the questionnaire. Based on endoscopic findings as well as the medical interview, the subjects were classified as having reflux disease (GERD) or non-reflux disease (non-GERD). Data mining models and algorithms (neural networks, decision trees, and logistic regression) were used to build a short and simple new discriminative questionnaire. The most relevant variables discriminating GERD from non-GERD patients were heartburn, regurgitation, clinical response to antacids, sour taste, and aggravation of symptoms after a heavy meal. The sensitivity and specificity of the new symptom score were 70%-75% and 63%-78%, respectively. The area under the ROC curve for logistic regression and neural networks were 0.783 and 0.787, respectively. We present a new validated discriminative GERD questionnaire using data mining techniques. The questionnaire is useful, friendly, and short, and therefore can be easily applied in clinical practice for choosing the appropriate diagnostic workup for patients with upper gastrointestinal complaints.

Oesophageal hypersensitivity is associated with features of psychiatric disorders and the irritable bowel syndrome

BACKGROUND

Twenty per cent of patients with heartburn do not respond to proton pump inhibitors (PPIs). Many have normal oesophageal acid exposure. We hypothesized that such PPI non-responders have heightened oesophageal sensation, and that oesophageal hypersensitivity is associated with psychiatric features including somatization and anxiety.

AIM

To compare oesophageal sensation in subjects with heartburn categorized by response to PPI, and to correlate oesophageal sensation with psychiatric features.

METHODS

Twenty-one PPI responders, nine PPI non-responders and 20 healthy volunteers completed questionnaires of psychiatric disorders and gastrointestinal symptoms. Subjects underwent oesophageal sensory testing with acid perfusion and balloon distension.

RESULTS

Healthy volunteers displayed higher thresholds for sensation and discomfort from balloon distension than heartburn subjects (sensation P = 0.04, discomfort P = 0.14). Psychiatric disorders were associated with increased intensity of sensation (P = 0.02) and discomfort from acid (P = 0.01). Somatization was associated with increased discomfort from balloon distension (P = 0.006). Features of irritable bowel syndrome were associated with increased sensation and discomfort.

CONCLUSIONS

Heartburn subjects tend to have heightened oesophageal sensation, suggesting that oesophageal hypersensitivity may persist despite therapy with PPI. Oesophageal hypersensitivity is associated with features of psychiatric disease and with the irritable bowel syndrome, which might partly explain the aetiology of heartburn symptoms that are refractory to PPI.

The Short-Form Leeds Dyspepsia Questionnaire validation study

BACKGROUND

Assessment of symptoms should be the primary outcome measure in dyspepsia clinical trials. This requires a reliable, valid and responsive questionnaire that measures the frequency and severity of dyspepsia. The Leeds Dyspepsia Questionnaire fulfils these characteristics, but is long and was not designed for self-completion, so a shorter questionnaire was developed (the Short-Form Leeds Dyspepsia Questionnaire).

AIM

To assess the acceptability, interpretability, internal consistency, reliability, validity and responsiveness of the Short-Form Leeds Dyspepsia Questionnaire in primary and secondary care.

METHODS

Unselected primary and secondary care patients completed the Short-Form Leeds Dyspepsia Questionnaire. Test-retest reliability was assessed after 2 days. Validity was measured by comparison with general practitioners' diagnosis. Sensitivity analysis and logistic regression were employed to determine the most valid scoring system. Responsiveness was determined before and after treatment for endoscopically proven disease.

RESULTS

The Short-Form Leeds Dyspepsia Questionnaire was administered to 388 primary care and 204 secondary care patients. The Pearson coefficient for test-retest reliability was 0.93. The Short-Form Leeds Dyspepsia Questionnaire had a sensitivity of 77% and a specificity of 75%. A highly significant response to change was observed (P < 0.005).

CONCLUSIONS

The Short-Form Leeds Dyspepsia Questionnaire is a reliable, valid and responsive self-completed outcome measure for quantifying the frequency and severity of dyspepsia symptoms, which is shorter and more convenient than the Leeds Dyspepsia Questionnaire.

Rosiglitazone/metformin fixed-dose combination compared with uptitrated metformin alone in type 2 diabetes mellitus: a 24-week, multicenter, randomized, double-blind, parallel-group study

BACKGROUND

Management of type 2 diabetes mellitus (DM) that involves uptitration of monotherapy to the maximum dose has been associated with delays in achieving glycemic control and an increased number of adverse events (AEs). Studies have reported the benefits of adding a thiazolidinedione to metformin (MET), but none has compared the effect of adding a thiazolidinedione to MET versus increasing the daily dose of MET to 3 g.

OBJECTIVE

The goal of this study was to investigate the benefits of fixed-dose combination rosiglitazone and MET (RSG/MET) compared with high-dose MET monotherapy in patients with type 2 DM.

METHODS

This was a 24-week, multicenter, randomized, double-blind, parallel-group study. Patients previously treated with MET entered a 4-week, single-blind, run-in period with MET 2 g/d and were then randomized to RSG/MET 4 mg/2 g per day or MET 2.5 g/d. At week 8, medication was escalated to RSG/MET 8 mg/2 g per day or MET 3 g/d. The primary efficacy end point was change in glycosylated hemoglobin (HbA1c) at week 24. Tolerability was assessed, including the frequency and severity of AEs.

RESULTS

A total of 568 patients comprised the safety population (MET, 280; RSG/MET, 288) and 551 formed the intent-to-treat group (MET, 272; RSG/MET, 279). Baseline characteristics of the safety population were comparable in the 2 groups; body mass index (mean [SD]) was 32.2 (4.8) kg/m(2) and 32.1 (4.9) kg/m(2) in the RSG/MET and MET groups, respectively. RSG/MET reduced HbA(1c) (mean [SD]) from 7.4% (1.0%) to 7.1% (1.1%) at week 24, compared with a reduction from 7.5% (1.0%) to 7.4% (1.1%) with MET (treatment difference, -0.22%; P = 0.001). Fasting plasma glucose (mean [SD]) was reduced from 166.2 (29) to 144.1 (33) mg/dL with RSG/MET and from 169.3 (33) to 164.0 (37) mg/dL with MET (treatment difference, -18.3 mg/dL; P < 0.001). In addition, 54% of patients treated with RSG/MET achieved HbA(1c) levels <7.0%, compared with 36% with MET (odds ratio, 2.42; P < 0.001). RSG/MET increased homeostasis model assessment (HOMA) estimates of insulin sensitivity by 34.4% versus 6.5% with MET (treatment difference, 24.8%; P < 0.001). HOMA beta-cell function increased by 15.9% with RSG/MET versus 2.5% with MET (treatment difference, 14.0%; P < 0.001). RSG/MET decreased C-reactive protein by a mean of 39.4% versus 16.0% with MET (treatment difference, -33.8%; P < 0.001). RSG/MET was generally well tolerated, with the majority of AEs mild to moderate in nature. Serious AEs were reported in 3% of patients receiving RSG/MET and 2% with MET. Overall rates of gastrointestinal AEs were 23% with RSG/MET and 26% with MET; however, there was an increased incidence of diarrhea (14% vs 6%) and abdominal pain (9% vs 6%) with MET. There was a mean (SE) increase in weight with RSG/MET (1.3 [0.22] kg) and a mean decrease (-0.9 [0.26] kg) with MET. Patients receiving RSG/MET reported improvements in treatment satisfaction compared with MET.

CONCLUSIONS

In this study, the RSG/MET fixed-dose combination (8 mg/2 g per day) was an effective and well-tolerated treatment for type 2 DM and enabled more patients to reach glycemic targets than high-dose MET (3 g/d).

Development and preliminary validation of the questionnaire on pediatric gastrointestinal symptoms to assess functional gastrointestinal disorders in children and adolescents

OBJECTIVE

The aim of this study was to develop a questionnaire assessing symptoms associated with pediatric functional gastrointestinal disorders (FGIDs) and to provide preliminary evidence for its validity and reliability in a tertiary care setting.

METHODS

The Questionnaire on Pediatric Gastrointestinal Symptoms (QPGS) was designed as both a parent report and child self-report measure based on the pediatric Rome II criteria for FGIDs. It was constructed in English, translated into French, and pilot tested in both languages. Initial validation was performed using the French version. Participants were 315 consecutive new patients aged 4 to 18, and their parents, presenting to a gastroenterology clinic and classified as having a functional problem. Content validity, item discrimination capacity, and reliability (parent-child concordance and temporal stability) were examined.

RESULTS

Analyses of parent and child reports indicated that all items were pertinent and variably distributed. Although children were reliable reporters, up to 42% of parents did not know about their children's gastrointestinal functioning. As many as 60% of parents of children 10 to 18 could not respond to questions about defecation and subjective symptoms. Concordance was generally fair to good, with Kappas and intraclass correlations of 0.40 to 0.70 on most items. Test-retest reliability was moderate to good for the majority of items.

CONCLUSION

This study supports the content validity of the QPGS. Form A is a reliable measure for parents of children 4 to 9 years old, but the child self-report Form C appears to be more reliable for 10 to 18 year olds.

Towards a better understanding of abdominal bloating and distension in functional gastrointestinal disorders

Abdominal bloating is an extremely common symptom affecting up to 96% of patients with functional gastrointestinal disorders and even 30% of the general population. To date bloating has often been viewed as being synonymous with an actual increase in abdominal girth, but recent evidence suggests that this is not necessarily the case. This review examines the relationship between the symptom of bloating and the physical sign of abdominal distension, as well as examining the epidemiology, pathophysiology and treatment options available for this debilitating aspect of the functional gastrointestinal disorders. Pathophysiological mechanisms explored include psychological factors, intestinal gas accumulation, fluid retention, food intolerance and malabsorption of sugars, weakness of abdominal musculature, and altered sensorimotor function. Treatment options are currently rather limited but include dietary changes, pharmacological approaches, probiotics and hypnotherapy.

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(TM)) are also applicable to the development of validated questionnaires for daily symptom self-assessment in other disease areas.

Symptom-based outcome measures for dyspepsia and GERD trials: a systematic review

BACKGROUND

Symptom assessment using questionnaires has been recommended as the primary outcome measure in clinical gastroesophageal reflux and dyspepsia trials. Questionnaires should have proven reliability, validity, and responsiveness, and may assess the frequency and/or severity of dyspepsia symptoms. Although a number of measures have been developed, it remains unclear which of these should be used in new trials.

OBJECTIVE

To describe existing questionnaire outcome measures that assess symptoms of gastroesophageal reflux dyspepsia for use in clinical trials.

METHODS

Studies were identified from Medline, Embase, the Cochrane library, and reference lists. The inclusion criterion was that the study assessed a questionnaire, which measured the frequency or severity of dyspepsia or gastroesophageal reflux symptoms, in a sample of patients.

RESULTS

No direct comparison between questionnaires was possible due to methodological heterogeneity. Thirty-seven studies describing 26 questionnaires met the inclusion criteria. Twelve were unidimensional (assessed symptoms only) and 14 were multidimensional (also assessed quality of life). Eleven questionnaires assessed both frequency and severity of dyspepsia, and 10 had proven reliability, validity, and responsiveness. No studies compared different questionnaires.

CONCLUSIONS

Future gastroesophageal reflux and dyspepsia clinical trials should use unidimensional or multidimensional outcome measures that assess both the frequency and severity of symptoms, and have proven reliability, validity, and responsiveness. Further research is necessary to compare existing outcome measures to determine which are the most reliable, valid, and responsive instruments.

Dyspepsia management in primary care: a management trial

The aim was to evaluate the outcomes associated with four initial management strategies in new patients presenting to primary care physicians with dyspepsia. Patients with new symptoms (no alarm features) were randomised to empirical therapy (n = 11), Helicobacter pylori (HP) serology (n = 8), HP breath testing (n = 11) or oesophagogastroduodenoscopy (n = 13). Dyspepsia and health-related quality of life were assessed using standardised questionnaires at entry, 6 and 24 weeks post-trial enrollment. Outcomes were assessed by structured telephone interview every 6 weeks. In the initial HP testing arms, 21% were positive; 27% in the oesophagogastroduodenoscopy arm had inflammatory changes without ulcers at baseline. The majority (67%) received over the counter medication after initial management. Symptom-free status was similarly common in all groups (p = 0.49); only 20% pursued further evaluation. Total billed charges were higher in the oesophagogastroduodenoscopy group (US 2077 dollars) vs. empirical therapy (US 512 dollars), despite excluding the charge for initial oesophagogastroduodenoscopy, but overall, no effects on total medical charges were detected (p = 0.10). Regardless of initial management, most patients remained symptomatic, yet did not return for health care visits or undergo endoscopies. The cost of upfront endoscopy may not be the best choice for patients presenting with new dyspepsia.

Validation of the Reflux Disease Questionnaire for a German population

OBJECTIVE

We describe the validation of a German-language version of the Reflux Disease Questionnaire in what is the first validation study of this patient questionnaire for a non-English speaking population. Gastro-oesophageal reflux disease is one of the most common diseases in primary care and has a significant negative impact on patients' quality of life. There is no gold standard for diagnosing gastro-oesophageal reflux disease, however, so the valid assessment of symptoms is especially important.

DESIGN AND METHODS

A total of 5689 patients (92%) completed the questionnaire both before treatment and after 2 weeks. The results were tested for validity and reliability. Predictive validity was tested in a pilot study of 100 patients. Convergent validity was examined using the Quality of Life in Reflux and Dyspepsia Questionnaire for the assessment of disease-specific quality of life and the McMaster Overall Treatment Evaluation for the assessment of therapeutic success.

RESULTS

Principal component analysis suggested a three-factor solution with the subscores heartburn, regurgitation, and dyspepsia. The internal consistencies of the subscores were between 0.84 and 0.86. Item difficulty ranged from 0.33 to 0.53, and corrected item-total correlation from 0.66 to 0.72. Effect sizes were between 0.8 and 1.0.

CONCLUSION

The German version of the questionnaire has good psychometric properties and is responsive to changes in health. Thus, we conclude that the German Reflux Disease Questionnaire is suitable for the assessment of heartburn, regurgitation, and treatment response, both in primary care settings and clinical studies.

Development and validation of a cross-cultural questionnaire to evaluate nonulcer dyspepsia: the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ)

Despite its high prevalence, nonulcer dyspepsia is still difficult to study, due to the lack of adequate tools to measure significant outcomes. The objective of this study was to develop and validate a symptom-focused, disease-specific questionnaire to evaluate patients with nonulcer dyspepsia. For that, the questionnaire was carefully written following widely accepted terminology, so as to facilitate translation and validation in other languages and cultures. The questionnaire was developed using Rome I terminology for symptoms, which were evaluated according to their intensity, duration, and frequency when applicable. Thirty-one patients with nonulcer dyspepsia, as well as 31 sex-and age-matched volunteers without digestive problems were used to assess the internal consistency, reproducibility, responsiveness, content validity, and discriminant validity of the questionnaire. Another 31 functional dyspeptic patients were enrolled for assessment of criterion validity. Cronbach's alpha coefficient was 0.82. The intraclass correlation coefficient for the scores obtained 7 days apart was 0.86. The mean score obtained after 3 months of treatment was 16.4, vs. 23.03 at baseline (P = 0.001). Two blinded gastroenterologists agreed that the questionnaire adequately evaluated nonulcer dyspepsia. The median symptoms score for controls was 0, vs. 22.5 for dyspeptic patients (P = 0.001). An inverse correlation was observed between quality of life and dyspeptic symptoms (R = -0.28, P = 0.026). The proposed questionnaire has high degrees of both reproducibility and responsiveness. As this questionnaire was based on Rome I International Consensus terminology, it is expected that it will be easy to translate and validate.

Treatment of gastro-oesophageal reflux disease with rabeprazole in primary and secondary care: does Helicobacter pylori infection affect proton pump inhibitor effectiveness?

BACKGROUND

The presence of the gastric pathogen, Helicobacter pylori influences acid suppression by proton pump inhibitors and treatment outcome in patients with gastro-oesophageal reflux disease.

AIM

To determine the influence of H. pylori infection on effectiveness of rabeprazole in primary and secondary care patients with gastro-oesophageal reflux disease.

METHODS

Patients from primary and secondary care centres with uninvestigated gastro-oesophageal reflux disease (based on symptoms only) and investigated gastro-oesophageal reflux disease (endoscopically confirmed oesophagitis or endoscopy-negative reflux disease) were tested for H. pylori and treated with rabeprazole 20 mg once daily for 4-8 weeks in a non-randomized, multicentre, open-label study. Primary end-point for treatment effectiveness was complete resolution of both heartburn and acid regurgitation at 4-8 weeks; secondary end-point was quality of life as registered with the Psychological General Well-being Index.

RESULTS

Data of 1787 patients could be analysed; mean duration of treatment was 36.3 days. At the evaluation visit 76.9% were heartburn-free, 77.7% regurgitation-free and 71% had complete symptom resolution. Overall Psychological General Well-being Index scores improved accordingly. Treatment was equally effective in patients with or without H. pylori infection, but more effective in patients with oesophagitis when compared with symptomatic gastro-oesophageal reflux disease.

CONCLUSIONS

The effectiveness of rabeprazole in gastro-oesophageal reflux disease is not affected by the presence of H. pylori infection.

Systematic review: 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 clinical trials.

AIM

To evaluate the validity of available GERD measurement tools.

METHODS

An ideal GERD symptom assessment instrument, suitable as a primary end-point for clinical trials, should possess the following characteristics: (i) be sensitive in patients with GERD; (ii) cover the frequency and intensity of typical and atypical GERD symptoms; (iii) be multidimensional (cover all symptom dimensions); (iv) have proven psychometric properties (validity, reliability and responsiveness); (v) be practical and economical; (vi) be self-assessed; (vii) use 'word pictures' which are easy to understand for patients; (viii) respond rapidly to changes (responsiveness over short time intervals); (ix) be used daily to assess changes during and after therapy; and (x) be valid in different languages for international use.

RESULTS

A literature review revealed five scales that met some of the above characteristics, but did not fulfil all criteria.

CONCLUSION

There is a need for a new evaluative tool for the assessment of GERD symptoms and their response to therapy.

Screening for Barrett's esophagus in colonoscopy patients with and without heartburn

BACKGROUND & AIMS

The population prevalence of Barrett's esophagus (BE) is uncertain. Our aim was to describe the prevalence of BE in a volunteer population.

METHODS

Upper endoscopy (EGD) was performed in 961 persons with no prior history of EGD who were scheduled for colonoscopy. Symptom questionnaires were completed prior to endoscopy. Biopsy specimens were taken from the gastric cardia and any columnar mucosa extending > or =5 mm into the tubular esophagus and from the stomach for H. pylori infection in the last 812 patients.

RESULTS

The study sample was biased toward persons undergoing colonoscopy, males, and persons with upper GI symptoms. The prevalence of BE was 65 of 961 (6.8%) patients, including 12 (1.2%) with long-segment BE (LSBE). Among 556 subjects who had never had heartburn, the prevalences of BE and LSBE were 5.6% and 0.36%, respectively. Among 384 subjects with a history of any heartburn, the prevalences of BE and LSBE were 8.3% and 2.6%, respectively. In a univariate analysis, LSBE was more common in those with any heartburn vs. those with no heartburn (P = 0.01), but the sample size was insufficient to allow multivariate analysis of predictors of LSBE. In a multivariate analysis, BE was associated with increasing age (P = 0.02), white race (P = 0.03), and negative H. pylori status (P = 0.04). Overall, BE was not associated with heartburn, although heartburn was more common in persons with LSBE or circumferential short segments.

CONCLUSIONS

LSBE is very uncommon in patients who have no history of heartburn. SSBE is relatively common in persons age > or =40 years with no prior endoscopy, irrespective of heartburn history.

Validation of Rome II criteria for functional gastrointestinal disorders by factor analysis of symptoms in Asian patient sample

BACKGROUND

It has been unclear as to whether the Rome II criteria could be applied to patients in the Asia region with functional gastrointestinal (GI) diseases. The aim of the present study was to determine if symptoms of Asian patients with functional gastrointestinal disorders formed groups which corresponded to the Rome II diagnostic criteria.

METHODS

A modified English version of Talley's bowel disease questionnaire was developed in collaboration with various research teams in accordance with the Rome II criteria. This instrument was translated into the local languages of the following nine Asian regions: China, Hong Kong, Indonesia, Korea, Malaysia, Singapore, Taiwan, Thailand and Vietnam. From September to December 2001, newly enrolled outpatients attending 14 GI or medical clinics in these regions were invited to complete the questionnaire. From these respondents, patients with functional gastrointestinal disorders fulfilling the '12 weeks out of 12 months' criteria were separated for further analysis. Principal component factor analysis with varimax rotation was used to identify symptom clusters or factors. These factors were compared with the existing classification of functional GI diseases derived from the Rome II criteria.

RESULTS

Factor analysis of symptoms from 1012 functional GI patients supported the Rome II classification of the following groups of functional GI disorders: diarrhea-predominant irritable bowel syndrome, functional constipation, functional dyspepsia, functional abdominal pain syndrome, functional heartburn, and functional vomiting. Functional diarrhea was combined with functional anorectal disorders, and globus merged with functional dysphagia into one factor. Some of the functional dyspepsia, abdominal bloating and belching symptoms were loaded into one factor.

CONCLUSIONS

Factor analysis of symptoms from a sample of Asian patients with functional GI disorders partially supported the use of the Rome II classification.

Cognitive interviewing: verbal data in the design and pretesting of questionnaires

PURPOSE

The purpose of this paper is to discuss problems that occur in questionnaire responses and how cognitive interviewing can be used to identify problematic questions prior to using the questionnaire in the field.

BACKGROUND

Questionnaire design involves developing wording that is clear, unambiguous and permits respondents successfully to answer the question that is asked. However, a number of problems in relation to respondents' understanding and successfully completing questionnaires have been identified. Cognitive interviewing, an amalgamation of cognitive psychology and survey methodology, has been developed to identify problematic questions that may elicit response error. The overall aim is to use cognitive theory to understand how respondents perceive and interpret questions and to identify potential problems that may arise in prospective survey questionnaires.

METHODS

A literature review is used to examine the process of questionnaire design and how cognitive interviewing can be used to reduce sampling error and increase questionnaire response rates.

FINDINGS

Cognitive interviewing involves interviewers asking survey respondents to think out loud as they go through a survey questionnaire and tell them everything they are thinking. This allows understanding of the questionnaire from the respondents' perspective rather than that of the researchers. Cognitive interviews have been used in a number of areas in health care research to pretest and validate questionnaires and to ensure high response rates. Interviewing has been found to be highly effective in developing questionnaires for age specific groups (children and adolescents) and in ascertaining respondents' understanding in health surveys prior to distribution. However, cognitive interviews have been criticized for being overly subjective and artificial.

CONCLUSION

Cognitive interviews are a positive addition to current methods of pretesting questionnaires prior to distribution to the sample. They are most valuable in pretesting questions that are complex, where questions are sensitive and intrusive and for specific groups for whom questionnaire completion may pose particular difficulties.

Outcome measures in irritable bowel syndrome: comparison of psychometric and methodological characteristics

OBJECTIVES

Although there is growing interest in irritable bowel syndrome (IBS) research, there is as yet no consensus regarding the preferred outcome measure. We aimed to evaluate and to compare the validity and appropriateness of available IBS outcome measures.

METHODS

IBS symptom and IBS health-related quality of life (HRQOL) scales were identified through a literature search. In a panel evaluation, six reviewers independently rated the scales according to predetermined psychometric and methodological validation criteria.

RESULTS

Five IBS symptom scales and five IBS HRQOL instruments were identified. Two of the symptom scales were rated as good. The Adequate Relief question scored best. This scale demonstrates responsiveness as well as face and construct validity, and its score was considered easy to interpret and appropriate for use. According to the reviewers, the IBS Severity Scoring System performed well with regard to psychometric capacities, but its practical utility was considered debatable. The properties of the other three symptom scales were suboptimal. The practical utility of the five IBS-specific HRQOL scales was considered poor. However, the reviewers agreed that, at present, the IBS Quality of Life measurement (Patrick et al.) is the best choice, because it has been the most extensively validated and shows appropriate psychometric quality.

CONCLUSIONS

The Adequate Relief question is the measure of first choice when assessing global symptomatology as an outcome in IBS studies. For a more detailed IBS symptom assessment, the IBS Severity Scoring System is preferable. Finally, the IBS Quality of Life measurement scale can be used to establish changes in health-related quality of life.

Clinical effectiveness of laparoscopic fundoplication in a U.S. community

BACKGROUND

The aim of our study was to determine the outcome of laparoscopic fundoplication for reflux disease in a cohort of patients who underwent this procedure in routine clinical practice.

METHODS

We identified 151 patients who had undergone laparoscopic fundoplication in a managed care organization in Milwaukee. Symptoms were evaluated using a validated questionnaire. Postoperative medication use and endoscopic and surgical procedures were recorded.

RESULTS

Eighty-seven patients agreed to participate, of whom 80 (41 [51%] men) were eligible. Their mean (+/- SD) age was 45 +/- 12 years, and the mean duration after surgery was 20 +/- 10 months. Thirty-six patients (45%) underwent the procedure because their physician recommended it, and 22 (27%) because they thought it would cure their disease. Forty-three patients (61%) were satisfied with the outcome of the procedure. Twenty-six patients (32%) were taking medications on a regular basis for treatment of heartburn, 9 (11%) required esophageal dilation for dysphagia, and 6 (7%) had repeat surgical procedures. Of the 54 patients (67%) who reported new symptoms after surgery, 38 reported excessive gas, 22 reported abdominal bloating, and 22 reported dysphagia. Health-related quality of life was significantly lower in patients with these symptoms.

CONCLUSION

Medical therapy is required for control of heartburn in approximately one third of patients after laparoscopic fundoplication. New symptoms are common after surgery. Patients need to be better informed about the indications and outcomes of surgery.

Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease

BACKGROUND & AIMS

Differentiating symptoms of irritable bowel syndrome (IBS) from those of organic intestinal disease is a familiar problem for physicians. The aim of this study was to assess the sensitivity, specificity, and odds ratios (ORs) of fecal calprotectin, small intestinal permeability, Rome I criteria, and laboratory markers of inflammation (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], blood count) in distinguishing organic from nonorganic intestinal disease.

METHODS

A total of 602 new referrals to a gastroenterology clinic who had symptoms suggestive of IBS or organic intestinal disease were studied for these parameters. All patients underwent invasive imaging (barium/endoscopic examination) and other investigations as appropriate, with physicians blinded to the results of fecal calprotectin and intestinal permeability.

RESULTS

A total of 263 patients were diagnosed with organic disease and 339 with IBS. At 10 mg/L, the sensitivity and specificity of calprotectin for organic disease were 89% and 79%, respectively, and that of intestinal permeability for small intestinal disease were 63% and 87%, respectively. Sensitivity of positive Rome criteria for IBS was 85% with a specificity of 71%. An abnormal calprotectin test had an OR for disease of 27.8 (95% confidence interval [CI], 17.6-43.7; P < 0.0001) compared with ORs of 4.2 (95% CI, 2.9-6.1; P < 0.0001) and 3.2 (95% CI, 2.2-4.6; P < 0.0001) for elevated CRP and ESR values. An abnormal permeability test gave an OR of 8.9 (95% CI, 5.8-14.0; P < 0.0001) for small intestinal disease. The OR for IBS with positive Rome criteria was 13.3 (95% CI, 8.9-20.0).

CONCLUSIONS

Fecal calprotectin, intestinal permeability, and positive Rome I criteria provide a safe and noninvasive means of helping differentiate between patients with organic and nonorganic intestinal disease.

Validation and results of a questionnaire for functional bowel disease in out-patients

BACKGROUND

The aim was to evaluate and validate a bowel disease questionnaire in patients attending an out-patient gastroenterology clinic in Greece.

METHODS

This was a prospective study. Diagnosis was based on detailed clinical and laboratory evaluation. The questionnaire was tested on a pilot group of patients. Interviewer-administration technique was used. One-hundred-and-forty consecutive patients attending the out-patient clinic for the first time and fifty healthy controls selected randomly participated in the study. Reliability (kappa statistics) and validity of the questionnaire were tested. We used logistic regression models and binary recursive partitioning for assessing distinguishing ability among irritable bowel syndrome (IBS), functional dyspepsia and organic disease patients.

RESULTS

Mean time for questionnaire completion was 18 min. In test-retest procedure a good agreement was obtained (kappa statistics 0.82). There were 55 patients diagnosed as having IBS, 18 with functional dyspepsia (Rome I criteria), 38 with organic disease. Location of pain was a significant distinguishing factor, patients with functional dyspepsia having no lower abdominal pain (p < 0.001). Significant factors distinguishing between IBS and functional dyspepsia were relief of pain by either antacids or defecation (19% vs 71% and 66% vs 0% respectively). Awakening from pain at night was also a factor distinguishing between IBS and organic disease groups (26% vs 61%, p < 0.01).

CONCLUSIONS

This questionnaire for functional bowel disease is a valid and reliable instrument that can distinguish satisfactorily between organic and functional disease in an out-patient setting.

The Hong Kong index of dyspepsia: a validated symptom severity questionnaire for patients with dyspepsia

AIM

Locally validated symptom questionnaires are essential instruments in dyspepsia research. A symptom score for Chinese dyspeptics was developed. Multiple aspects of validity and reliability were assessed.

METHODS

Sixty-five patients with endoscopy-negative dyspepsia and 65 healthy controls were presented with a list of 24 previously determined common abdominal symptoms and asked to rate the severity in a five point Likert scale. Comprehensibility and relevance of symptoms were assessed. The questionnaire was administered 3 h later to assess for reproducibility. A locally validated Short Form-36 quality-of-life questionnaire was also administered. Cisapride 5 mg thrice daily was prescribed to dyspeptic patients but not to the controls. The dyspepsia symptom and SF-36 questionnaires were repeated after 3 weeks for patients under treatment. Global change in symptoms and the need for further medical care were assessed. Concept, content, construct and criterion validity, consistency and reproducibility of the dyspepsia symptom questionnaire were assessed.

RESULTS

All items were considered comprehensible by more than 90% of subjects. Relevance of individual symptoms to dyspeptic patients ranged from 10.8-76.9%. Twelve items were selected by logistic regression to account for most of the differences between control and dyspeptic patients. Test-retest reproducibility and internal consistency were good with the intraclass correlation coefficient of 0.89 and Cronbach's alpha coefficient of 0.90. A cut-off score of equal to or greater than 16 was determined to discriminate between controls and dyspeptic patients. The dyspepsia score correlated negatively with all domains of the SF-36 quality of life scale except physical functioning. The dyspepsia questionnaire also discriminated between patients who reported a subjective improvement in symptoms and those who reported no change or worsening.

CONCLUSIONS

The dyspepsia symptom index was easy to understand, internally consistent and reproducible. It predicted global symptom change, and the symptom severity scores correlated negatively with quality of life.

Health-related quality of life and gastrointestinal disease

Society is changing rapidly, and new aspects need to be considered when evaluating treatment of disease. Health-related quality of life (HRQL) is a relatively new addition to the tools clinicians use to gain a better understanding of the impact of disease and its treatment. The questions 'What is it?', 'How it is measured?' and 'How can the information be used?' are now better understood than a few years ago. Generic instruments to capture HRQL enable a broad assessment of a range of aspects and can be used to make comparisons between different patient populations. Irrespective of the choice of instrument, they can classify the influence of different factors, such as gender, age, general health status and disease severity. Health-related quality of life assessments have been made in many areas of gastroenterology, such as reflux disease, inflammatory bowel disease and irritable bowel syndrome, to describe the burden of illness and the impact of treatment. Health-related quality of life as a prediction of treatment response is another interesting option. Its ability in the context of surgical intervention and outcomes is also emerging even though more work must be done in this area. Health-related quality of life evaluations, as an additional tool in the management of patients, are here to stay.

Reliability and validity of the digestive health status instrument in samples of community, primary care, and gastroenterology patients

AIM

We evaluated a previously reported digestive health status instrument in community, primary care, and gastroenterology practice populations. Multiple types of reliability, validity and responsiveness were assessed to determine the performance of the questionnaire.

METHODS

Study populations included community, primary care and gastroenterology subjects. Psychometric analyses included internal consistency and test-retest reliability, criterion and construct validity, and responsiveness.

RESULTS

Acceptable internal consistency was seen on all scales in all three populations. Test-retest reliability was excellent in a speciality population with reflux disease. Criterion validity was demonstrated by strong correlation of reflux scale scores and results on 24-h pH monitoring. Scale scores varied predictably in those receiving gastrointestinal tract imaging and according to diagnosis, indicating construct validity. The reflux scale and pain index were sensitive to change with treatment for reflux disease. Multi-trait scaling analyses from the community sample revealed a structure equivalent to that reported from a primary care sample.

CONCLUSIONS

The reliability and validity of the digestive health status instrument on multiple measures in multiple settings have been demonstrated. The instrument was responsive to change with treatment for reflux disease. The demonstrated robustness attests to the suitability for future studies and clinical application.