Gastroprotective strategies in chronic NSAID users: a cost-effectiveness analysis comparing single-tablet formulations with individual components.

OBJECTIVES: To evaluate the cost-effectiveness of competing gastroprotective strategies, including single-tablet formulations, in the prevention of gastrointestinal (GI) complications in patients with chronic arthritis taking nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: We performed a cost-utility analysis to compare eight gastroprotective strategies including NSAIDs, cyclooxygenase-2 inhibitors, proton pump inhibitors (PPIs), histamine-2 receptor antagonists, misoprostol, and single-tablet formulations. We derived estimates for outcomes and costs from medical literature. The primary outcome was incremental cost per quality-adjusted life-year gained. We performed sensitivity analyses to assess the effect of GI complications, compliance rates, and drug costs. RESULTS: For average-risk patients, NSAID + PPI cotherapy was most cost-effective. The NSAID/PPI single-tablet formulation became cost-effective only when its price decreased from €0.78 to €0.56 per tablet, or when PPI compliance fell below 51% in the NSAID + PPI strategy. All other strategies were more costly and less effective. The model was highly sensitive to the GI complication risk, costs of PPI and NSAID/PPI single-tablet formulation, and compliance to PPI. In patients with a threefold higher risk of GI complications, both NSAID + PPI cotherapy and single-tablet formulation were cost-effective. CONCLUSIONS: NSAID + PPI cotherapy is the most cost-effective strategy in all patients with chronic arthritis irrespective of their risk for GI complications. For patients with increased GI risk, the NSAID/PPI single-tablet formulation is also cost-effective.

Gastroprotection in low-dose aspirin users for primary and secondary prevention of ACS: results of a cost-effectiveness analysis including compliance.

PURPOSE: Low-dose aspirin (ASA) increases the risk of upper gastrointestinal (GI) complications. Proton pump inhibitors (PPIs) reduce these upper GI side effects, yet patient compliance to PPIs is low. We determined the cost-effectiveness of gastroprotective strategies in low-dose ASA users considering ASA and PPI compliance. METHODS: Using a Markov model we compared four strategies: no medication, ASA monotherapy, ASA+PPI co-therapy and a fixed combination of ASA and PPI for primary and secondary prevention of ACS. The risk of acute coronary syndrome (ACS), upper GI bleeding and dyspepsia was modeled as a function of compliance and the relative risk of developing these events while using medication. Costs, quality adjusted life years and number of ACS events were evaluated, applying a variable risk of upper GI bleeding. Probabilistic sensitivity analyses were performed. RESULTS: For our base case patients using ASA for primary prevention of ACS no medication was superior to ASA monotherapy. PPI co-therapy was cost-effective (incremental cost-effectiveness ratio [ICER] €10,314) compared to no medication. In secondary prevention, PPI co-therapy was cost-effective (ICER €563) while the fixed combination yielded an ICER < €20,000 only in a population with elevated risk for upper GI bleeding or moderate PPI compliance. PPI co-therapy had the highest probability to be cost-effective in all scenarios. PPI use lowered the overall number of ACS. CONCLUSIONS: Considering compliance, PPI co-therapy is likely to be cost-effective in patients taking low dose ASA for primary and secondary prevention of ACS, given low PPI prices. In secondary prevention, a fixed combination seems cost-effective in patients with elevated risk for upper GI bleeding or in those with moderate PPI compliance. Both strategies reduced the number of ACS compared to ASA monotherapy.

Direct medical care costs among pegylated interferon plus ribavirin-treated and untreated chronic hepatitis C patients.

BACKGROUND: Hepatitis C virus (HCV) is a common and expensive infectious disease. The current standard of care for HCV infection, pegylated interferon with ribavirin (PEG-RBV), is costly and has a significant adverse event profile. AIM: To quantify the direct economic burden of HCV infection and PEG-RBV treatment for HCV. METHODS: Using a large administrative claims database, we evaluated the medical and prescription drug costs of patients with HCV from 2002 to 2007. A cohort of patients with PEG-RBV was 1:1 propensity score-matched to a cohort of untreated HCV patients. Multivariate models adjusted for demographic and clinical characteristics in evaluating the effect of PEG-RBV treatment on direct medical expenditure. RESULTS: The matched analysis included 20,002 patients. PEG-RBV-treated patients had higher total direct medical costs ($28,547 vs. $21,752; P < 0.001), outpatient pharmacy costs ($17,419 vs. $2,900; P < 0.001), and outpatient physician visit costs ($894 vs. $787; P < 0.001), but lower inpatient costs ($3,942 vs. $9,543; P < 0.001) and emergency room costs ($366 vs. $505; P < 0.001). After multivariate adjustment, PEG-RBV use was associated with an additional $9,423 in total direct medical costs and an additional $12,244 in HCV-related total medical costs. CONCLUSION: Total HCV-related medical costs are higher for treated than untreated patients, driven mostly by higher outpatient pharmacy costs, which outweigh higher HCV-related inpatient costs incurred by untreated patients.

Functional GI disorders: from animal models to drug development.

Despite considerable efforts by academic researchers and by the pharmaceutical industry, the development of novel pharmacological treatments for irritable bowel syndrome (IBS) and other functional gastrointestinal (GI) disorders has been slow and disappointing. The traditional approach to identifying and evaluating novel drugs for these symptom-based syndromes has relied on a fairly standard algorithm using animal models, experimental medicine models and clinical trials. In the current article, the empirical basis for this process is reviewed, focusing on the utility of the assessment of visceral hypersensitivity and GI transit, in both animals and humans, as well as the predictive validity of preclinical and clinical models of IBS for identifying successful treatments for IBS symptoms and IBS-related quality of life impairment. A review of published evidence suggests that abdominal pain, defecation-related symptoms (urgency, straining) and psychological factors all contribute to overall symptom severity and to health-related quality of life. Correlations between readouts obtained in preclinical and clinical models and respective symptoms are small, and the ability to predict drug effectiveness for specific as well as for global IBS symptoms is limited. One possible drug development algorithm is proposed which focuses on pharmacological imaging approaches in both preclinical and clinical models, with decreased emphasis on evaluating compounds in symptom-related animal models, and more rapid screening of promising candidate compounds in man.

Systematic review: the prevalence of suicidal behaviour in patients with chronic abdominal pain and irritable bowel syndrome.

BACKGROUND: Chronic abdominal pain syndromes may increase the risk of suicidal behaviour - a feature well described in non-visceral pain syndromes. AIM: To perform a systematic review to summarize and interpret published data linking chronic abdominal pain syndromes and suicidal behaviour. METHODS: We performed a structured search to identify studies pertaining to the following questions: (i) What is the prevalence of suicidal behaviour in patients with chronic abdominal pain syndromes, including bowel syndrome (IBS)? (ii) Is the prevalence of suicidal behaviour in chronic abdominal pain syndromes higher than in matched controls? And (iii) is suicidal behaviour in abdominal pain syndromes simply due to psychiatric co-morbidities? RESULTS: Thirty-two relevant titles were identified, of which six manuscripts, describing eight studies, met inclusion criteria. Patients with non-IBS syndromes were 3-11 times more likely to demonstrate suicidal behaviour vs. controls, while patients with IBS were two to four times more likely to have suicidal behaviour. Chronic abdominal pain was an independent predictor of suicidal behaviour after adjusting for co-morbid psychiatric conditions. CONCLUSIONS: Chronic abdominal pain syndromes increase the risk for suicidal behaviours. This relationship may exist independently of co-morbid depression, although additional research is needed to better understand this link. These data indicate that clinicians should survey for suicidal behaviour in chronic abdominal pain patients.

The cost-effectiveness and budget impact of competing therapies in hepatic encephalopathy - a decision analysis.

BACKGROUND: Treatment options for hepatic encephalopathy have disparate risks and benefits. Non-absorbable disaccharides and neomycin are limited by uncertain efficacy and common dose-limiting side effects. In contrast, rifaximin is safe and effective in hepatic encephalopathy, but is more expensive. METHODS: We conducted a decision analysis to calculate the cost-effectiveness of six strategies in hepatic encephalopathy: (i) no hepatic encephalopathy treatment, (ii) lactulose monotherapy, (iii) lactitol monotherapy, (iv) neomycin monotherapy, (v) rifaximin monotherapy and (vi) up-front lactulose with crossover to rifaximin if poor response or intolerance of lactulose ('rifaximin salvage'). The primary outcome was cost per quality-adjusted life-year gained. RESULTS: Under base-case conditions, 'do nothing' was least effective and rifaximin salvage was most effective. Lactulose monotherapy was least expensive, and rifaximin monotherapy was most expensive. When balancing cost and effectiveness, lactulose monotherapy and rifaximin salvage dominated alternative strategies. Compared to lactulose monotherapy, rifaximin salvage cost an incremental US$2315 per quality-adjusted life-year-gained. The cost of rifaximin had to fall below US$1.03/tab in order for rifaximin monotherapy to dominate lactulose monotherapy. CONCLUSIONS: Rifaximin monotherapy is not cost-effective in the treatment of chronic hepatic encephalopathy at current average wholesale prices. However, a hybrid salvage strategy, reserving rifaximin for lactulose-refractory patients, may be highly cost-effective.

Differences in the management of Crohn's disease among experts and community providers, based on a national survey of sample case vignettes.

BACKGROUND: When faced with the same set of facts, healthcare providers often make different diagnoses, employ different tests and prescribe disparate therapies. AIM: To perform a national survey to measure process of care and variations in decision-making in Crohn's disease, and the compared results between experts and community providers. METHODS: We constructed a survey with five vignettes to elicit provider beliefs regarding the appropriateness of diagnostic tests and therapies in Crohn's disease. We measured agreement between community gastroenterologists and Crohn's disease experts, and measured variation within each group using the RAND Disagreement Index (DI), which is a validated measure of provider variation. RESULTS: We received 186 responses (42% response rate). Experts and community providers generally agreed on diagnostic testing decisions in Crohn's disease. However, there was a significant disagreement between groups for several decisions (use of 5-aminosalicylate in particular), and there was evidence of 'extreme variation' (defined as DI > 1.0) within groups across a range of decisions. CONCLUSIONS: Although experts and community providers are in general consensus about diagnostic decision-making in Crohn's disease, extreme variation exists both between and within groups for key therapeutic decisions in Crohn's disease. We must understand and decrease this variation prior to future efforts of creating explicit quality indicators in Crohn's disease.

Gastrointestinal symptom severity in irritable bowel syndrome, inflammatory bowel disease and the general population.

BACKGROUND: Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) patients report similar gastrointestinal (GI) symptoms, yet comparisons of symptom severity between groups and with the general population (GP) are lacking. METHODS: We compared Patient-Reported Outcomes Measurement Information System (PROMIS® ) GI symptom scales measuring gastro-esophageal reflux (GER), disrupted swallowing, diarrhea, bowel incontinence, nausea/vomiting, constipation, belly pain, and gas/bloating in: (i) USA GP sample, (ii) IBS patients, and (iii) IBD patients from tertiary care and community populations. Symptom severity scores were based on T-score metric with mean 50±10 (standard deviation) relative to the GP. KEY RESULTS: Of 1643 patients enrolled, there were 253 IBS patients (68% F, mean age 45±15 years), 213 IBD patients (46% F, mean age 41±14 years), and 1177 GP subjects (57% F, mean age 46±16 years). IBS patients reported greater severity of GER, disrupted swallowing, nausea/vomiting, belly pain, gas/bloating, and constipation symptoms than their IBD counterparts (all P<.05). Compared to the GP, IBD patients had worse belly pain, gas/bloating, diarrhea, and bowel incontinence, but less severe GER and disrupted swallowing (all P<.05), and IBS patients had more severe nausea/vomiting, belly pain, gas/bloating, and constipation (all P<.05). Women had more severe belly pain and gas/bloating than men, whereas men had more severe bowel incontinence (all P<.05). CONCLUSION & INFERENCES: IBS and IBD are associated with more severe GI symptoms compared to the GP excluding esophageal symptoms. Unlike IBD, IBS is not characterized by observable GI inflammation but patients report more severe upper and lower GI symptoms.

A comparison of liver transplantation outcomes in the pre- vs. post-MELD eras.

BACKGROUND: The model for end stage liver disease (MELD)-based organ allocation system is designed to prioritize orthotopic liver transplantation (OLT) for patients with the most severe liver disease. However, there are no published data to confirm whether this goal has been achieved or whether the policy has affected long-term post-OLT survival. AIM: To compare pre-OLT liver disease severity and long-term (1 year) post-OLT survival between the pre- and post-MELD eras. METHODS: Using the United Network of Organ Sharing database, we compared two cohorts of adult patients undergoing cadaveric liver transplant in the pre-MELD (n = 3857) and post-MELD (n = 4245) eras. We created multivariable models to determine differences in: (i) pre-OLT liver disease severity as measured by MELD; and (ii) 1-year post-OLT outcomes. RESULTS: Patients undergoing OLT in the post-MELD era had more severe liver disease at the time of transplantation (mean MELD = 20.5) vs. those in the pre-MELD era (mean MELD = 17.0). There were no differences in the unadjusted patient or graft survival at 1 year post-OLT. This difference remained insignificant after adjusting for a range of prespecified recipient, donor, and transplant centre-related factors in multivariable survival analysis. CONCLUSIONS: Although liver disease severity is higher in the post- vs. pre-MELD era, there has been no change in long-term post-OLT patient or graft survival. These results indicate that the MELD era has achieved its primary goals by allocating cadaveric livers to the sickest patients without compromising post-OLT survival.

"Anxietas tibiarum". Depression and anxiety disorders in patients with restless legs syndrome.

BACKGROUND: Symptoms of anxiety and depression in patients with restless legs syndrome (RLS) have been observed. However, it is unclear whether rates of threshold depression and anxiety disorders according to DSM-IV criteria in such patients are also elevated. METHODS: 238 RLS patients were assessed with a standardized diagnostic interview (Munich-Composite International Diagnostic Interview for DSM-IV) validated for subjects aged 18-65 years. Rates of anxiety and depressive disorders were compared between 130 RLS patients within this age range and 2265 community respondents from a nationally representative sample with somatic morbidity of other types. RESULTS: RLS patients revealed an increased risk of having 12-month anxiety and depressive disorders with particularly strong associations with panic disorder (OR=4.7; 95% CI=2.1-10.1), generalized anxiety disorder (OR=3.5; 95% CI= 1.7-7.1), and major depression (OR=2.6; 95% CI=1.5-4.4). In addition, lifetime rates of panic disorder and most depressive disorders as well as comorbid depression and anxiety disorders were considerably increased among RLS patients compared with controls. CONCLUSIONS: The results suggest that RLS patients are at increased risk of having specific anxiety and depressive disorders. Causal attributions of patients suggest that a considerable proportion of the excess morbidity for depression and panic disorder might be due to RLS symptomatology.

Endoscopy for acute nonvariceal upper gastrointestinal tract hemorrhage: is sooner better? A systematic review.

BACKGROUND: While the effectiveness of upper endoscopy has been established for acute nonvariceal upper gastrointestinal tract hemorrhage, its optimal timing has not been clearly defined. Early endoscopy has been advocated for its ability to achieve prompt diagnosis, risk stratification, and therapeutic hemostasis. OBJECTIVE: To determine whether early vs delayed endoscopy improves patient and economic outcomes for all risk groups with nonvariceal upper gastrointestinal tract hemorrhage. METHODS: A systematic review of 3 computerized databases (MEDLINE, HEALTHSTAR, and Cochrane Database of Systematic Reviews) was performed along with hand searching of published abstracts to identify English-language citations from 1980 to 2000. RESULTS: Twenty-three studies met explicit inclusion criteria. The highest-quality study examining outcomes in low-risk patients found no significant complications at 1-month follow-up for any outpatients managed with early endoscopy. The largest randomized trial of high-risk patients showed no mortality benefit but a significant decrease in transfusion requirements with early endoscopy. Seven of the 8 studies examining the effect of early endoscopy on length of stay as a measure of resource utilization demonstrated a significant reduction compared with that of delayed endoscopy. However, most included studies were found to suffer from 1 or more potentially significant methodologic shortcomings. CONCLUSIONS: The overwhelming majority of existing data suggest that early endoscopy is safe and effective for all risk groups. The clinical and economic outcomes of early endoscopy should be confirmed in additional well-designed randomized controlled trials. Given the strength of the evidence, efforts to develop a more standardized and time-sensitive approach to acute nonvariceal upper gastrointestinal tract hemorrhage should be undertaken.

Traditional Chinese medicine based subgrouping of irritable bowel syndrome patients.

Partly from lack of effective conventional therapeutics, patients with irritable bowel syndrome (IBS) turn to complementary and alternative approaches, including Traditional Chinese Medicine (TCM). Key to TCM's approach to IBS is individualized therapies targeted at subgroups. Subgroups represent distinct patterns of dysregulation (e.g. "excess" or "deficiency") identified by both intestinal and extra-intestinal symptoms. Our objective was to identify operational criteria supporting the existence of TCM-based subgroups in IBS and to assess reliability and validity of these criteria. Using TCM principles, items were selected on face validity from conventional questionnaires. TCM practitioners evaluated items for content and face validity. Symptom items and a set of patient cases with item responses were validated by examining patient's pattern of response to items and assessing the consistency with which practitioners diagnosed patients on the spectrum of an "excess" or "deficiency" syndrome. Standard correlation analysis revealed 33 intestinal and extra-intestinal symptom items. There was high degree of practitioner agreement in assessing individual items to particular patterns. External validation by practitioners of cases showed high internal consistency among practitioners (Cronbach's alpha coefficients of 0.91 and 0.87 for excess and deficiency, respectively) and high correlation of average practitioner rating to original questionnaire generated scores (Pearson correlation coefficients of 0.94 and 0.92 for excess and deficiency, respectively). This pilot study provides preliminary support for a methodology to identify novel subgroups of IBS patients related to the TCM classification, which may differ in underlying pathophysiology and treatment responses.

The yield and cost of colonoscopy in patients with metastatic cancer of unknown primary.

BACKGROUND: Although gastroenterologists are asked to perform colonoscopy in patients with metastatic cancer of unknown primary (MCUP), studies evaluating this practice are lacking. AIM: To determine the yield and cost of colonoscopy in patients referred for colonoscopy with an indication of MCUP. METHODS: We prospectively and retrospectively assessed colonoscopies performed from 2000 to 2011 at a county, a university, and a Veterans Administration medical centre to identify patients referred for colonoscopy for the indication of MCUP. Exclusion criteria included overt or occult bleeding, iron-deficiency anaemia, familial-colon-cancer syndrome, prior colon cancer, imaging suggesting colorectal lesion, and palpable rectal mass. Outcomes were the number of primary colon cancers and costs based on 2012 Medicare reimbursements. RESULTS: Two (1%) of the 160 patients meeting enrollment criteria had a primary colon cancer identified, and both died within 1 month after diagnosis without receiving therapy targeted at colon cancer. One patient without colon cancer had a perforation because of colonoscopy, which required surgery and colostomy. The cost of a strategy of routinely performing colonoscopy in patients referred with MCUP was $84 736 per colon primary identified. CONCLUSIONS: Primary colon cancer was rarely identified at colonoscopy in patients with MCUP and no standard indications for diagnostic colonoscopy. Furthermore, the cost to diagnose one additional colon primary was very high. Those with colon cancer had advanced disease and were unable to benefit from targeted therapy. Routine colonoscopy for MCUP cannot be recommended at present.

Setting priorities for comparative effectiveness research in inflammatory bowel disease: results of an international provider survey, expert RAND panel, and patient focus groups.

BACKGROUND: Comparative effectiveness research (CER) is an emerging field that compares the relative effectiveness of alternative strategies to prevent, diagnose, or treat patients who are typical of day-to-day practice. We developed a priority list of CER topics for inflammatory bowel disease (IBD). METHODS: Following the Institute of Medicine's approach, we developed and administered a survey to gastroenterologists asking for important CER topics in IBD. Two patient focus groups were convened to solicit additional CER studies. CER topics were presented to the expert panel using the RAND/UCLA methodology. Following initial ratings, the panel met to discuss and re-rate priorities. The top 10 CER topics were identified using a point-allocation system. RESULTS: Responses were collated into 234 CER topics across 21 categories, of which 87 were prioritized for discussion and re-rated. Disagreement regarding priorities was observed in 5 of 87 studies. We utilized a point-allocation system to prioritize the top-10 CER topics. These related to comparing the effectiveness of: biomarkers in IBD; withdrawal of anti-tumor necrosis factor (TNF) or immunomodulators for Crohn's disease in remission; mucosal healing as an endpoint of treatment; infliximab levels versus standard infliximab dosing; anti-TNF monotherapy versus combination therapy in patients failing thiopurines; safety of long-term treatment options; anti-TNF versus thiopurines for prevention of postoperative recurrence; and treatment options for steroid-refractory UC. CONCLUSIONS: We systematically developed a list of high-priority IBD topics for CER based on a survey of gastroenterologists, expert review, and patient input. This list may guide IBD research toward the most important CER studies.

Meta-analysis: do irritable bowel syndrome symptoms vary between men and women?

BACKGROUND: Studies suggest that sex and gender-related differences exist in irritable bowel syndrome (IBS), but data is often conflicting. AIM: To evaluate gender differences and the effect of menstrual cycle and menopausal status on IBS symptoms. METHODS: We performed a systematic review of MEDLINE to search for studies comparing IBS symptoms between gender, menstrual cycle phases and menopausal states in IBS and/or healthy individuals. We performed meta-analyses to compare the relative risk (RR) of individual IBS symptoms between men and women. RESULTS: Twenty-two studies measured gender differences in IBS symptoms. Women were more likely to report abdominal pain (RR = 1.12, 95% CI: 1.02, 1.22) and constipation-related symptoms (RR = 1.12, 95% CI: 1.02, 1.23) than men (all P < 0.05). However, men with IBS were more likely to report diarrhoea-related symptoms than women with IBS (RR = 0.84, 95% CI: 0.75, 0.94, P < 0.05). A systematic review of 13 studies demonstrated that both IBS and healthy women reported increased IBS symptoms during menses vs. other phases. There were insufficient data to determine the effect of menopause and hormone supplementation on IBS symptoms. CONCLUSIONS: In the general and IBS populations, gender differences in IBS symptoms exist, although these differences are modest. Studies suggest that female sex hormones influence the severity of IBS symptoms, but more studies are needed.

The development and validation of a Nocturnal Gastro-oesophageal Reflux Disease Symptom Severity and Impact Questionnaire for adults.

BACKGROUND: Current questionnaires for assessing gastro-oesophageal reflux disease (GERD) symptoms are limited in their ability to capture nocturnal symptoms. AIM: To develop and validate an instrument, the Nocturnal Gastro-oesophageal Reflux Disease Symptom Severity and Impact Questionnaire (N-GSSIQ), to assess severity and impact of nocturnal GERD symptoms. METHODS: Two focus groups and 16 cognitive debriefing interviews were conducted among GERD patients to identify key issues about nocturnal symptoms. A draft instrument was tested in 196 patients at 11 clinics in the US to evaluate psychometric properties. Exploratory factor and item response theory analyses were conducted to finalize items and subscales. Internal consistency reliability, reproducibility and construct validity were examined. RESULTS: Mean age was 45 (s.d. = 13.8) years; 76% were female and 68% were Caucasian. Patient-rated severity was mild-moderate for 69% of participants; 48% reported symptoms on two to three nights the past week. The final questionnaire includes 20 items and three subscales: Nocturnal GERD Symptoms, Morning Impact of Nocturnal GERD and Concern about Nocturnal GERD. The subscales demonstrated internal consistency reliability (Cronbach's alpha 0.84-0.94) and were significantly correlated with similar measures and disease severity (0.41-0.81; P < 0.0001). CONCLUSION: The results support the reliability and validity of the N-GSSIQ as a measure of severity, morning impact and concern about nocturnal GERD.

Measuring symptoms in the irritable bowel syndrome: development of a framework for clinical trials.

BACKGROUND: There is uncertainty about how to measure patient-reported outcomes (PROs) in IBS. The Food and Drug Administration (FDA) emphasizes that PROs must be couched in a conceptual framework, yet existing IBS PROs were not based on such a framework. AIM: To perform qualitative analyses to inform a new conceptual framework for IBS symptoms. METHODS: Following FDA guidance, we searched the literature for extant IBS questionnaires. We then performed interviews in IBS patients to learn about the illness experience in their own words. We cultivated vocabulary to inform a conceptual framework depicted with domains, sub-domains, and item categories, per FDA guidance. RESULTS: We identified 13 questionnaires with items encompassing 18 symptoms. We recruited 123 IBS patients for cognitive interviews. Major themes included: pain and discomfort are different - asking about discomfort is nonspecific and should be avoided in future PROs; bowel urgency is multifaceted - PROs should measure bowel immediacy, controllability, and predictability; and PROs should divide bloating into how it feels vs. how it looks. Symptom experience may be determined by 35-item categories within five domains: (i) pain; (ii) gas/bloat; (iii) diarrhoea; (iv) constipation; and (v) extraintestinal symptoms. CONCLUSIONS: We applied FDA guidance to develop a framework that can serve as the foundation for developing a PRO for IBS clinical trials.

Characterizing abdominal pain in IBS: guidance for study inclusion criteria, outcome measurement and clinical practice.

BACKGROUND: Although irritable bowel syndrome (IBS) is a multisymptom disorder, abdominal pain drives illness severity more than other symptoms. Despite consensus that IBS trials should measure pain to define study entry and determine efficacy, the optimal method of measuring pain remains uncertain. AIM: To determine whether combining information from multiple pain dimensions may capture the IBS illness experience more effectively than the approach of measuring 'pain predominance' or pain intensity alone. METHODS: Irritable bowel syndrome patients rated dimensions of pain, including intensity, frequency, constancy, predominance, predictability, duration, speed of onset and relationship to bowel movements. We evaluated the impact of each dimension on illness severity using multivariable regression techniques. RESULTS: Among the pain dimensions, intensity, frequency, constancy and predictability were strongly and independently associated with illness severity; the other dimensions had weaker associations. The clinical definition of 'pain predominance', in which patients define pain as their most bothersome symptom, was insufficient to categorize patients by illness severity. CONCLUSIONS: Irritable bowel disease pain is multifaceted; some pain dimensions drive illness more than others. IBS trials should measure various pain dimensions, including intensity, constancy, frequency and predictability; this may improve upon the customary use of measuring pain as a unidimensional symptom in IBS.