Adequate Relief as an Endpoint in Clinical Trials in Irritable Bowel Syndrome

Abstract

Irritable bowel syndrome is characterized by recurrent abdominal pain and altered bowel function. In designing studies to evaluate new treatments for this disease, however, it is difficult to select appropriate endpoints to reflect improvement in the range of symptoms of the syndrome. In the present study we evaluated the parameter of adequate relief of abdominal pain and discomfort, as perceived by the patients, as a key endpoint for efficacy in the treatment of patients with irritable bowel syndrome. Abdominal pain and bowel function data were collected daily from 370 patients with the disease during treatment with placebo or a novel potent 5HT3 receptor antagonist. Once every 7 days adequate relief of pain and discomfort was assessed. Quality-of-life data were collected using self-administered questionnaires. The endpoint of adequate relief was significantly (P < 0.05) correlated with improvement in pain severity scores, percentage of pain-free days, percentage of days with urgency, improvement in stool frequency and consistency, and quality-of-life parameters. Adequate relief of pain and discomfort is significantly correlated with changes in multiple parameters associated with irritable bowel syndrome and can be used as an endpoint for assessing response to therapy in these patients.

Effect of Amitriptyline and Escitalopram on Functional Dyspepsia: A Multicenter, Randomized Controlled Study

“…This study utilized “adequate relief” as its primary outcome, which has been used and accepted in other functional GI trials such as IBS. 23, 40 Although Rome III criteria were not applied because the study began prior to their publication, the present data suggest epigastric pain syndrome and ulcer-like dyspepsia cover similar domains. This study’s execution and interpretation of results were regularly overseen by the National Institutes of Health and the Data and Safety Monitoring Board.…”

“…22, 23 This self-report measure is considered clinically relevant and has been tested for responsiveness in FD. 24, 25 The disease-specific validated Nepean Dyspepsia Index (NDI) was used to assess FD quality-of-life 26 at baseline and post-treatment.…”

Improvement in irritable bowel syndrome following ano-rectal surgery

“…Mangel et al [22] found that adequate relief of abdominal pain is significantly correlated with changes in the multiple parameters associated with IBS (such as changes in bowel habit, incomplete emptying and bloating) and can be used as an endpoint for assessing response to therapy. In our series 70% claimed the abdominal pains were less frequent, and 69% gave high scores for the overall improvement in their IBS symptoms.…”

Protocol for a randomized controlled study of Iyengar yoga for youth with irritable bowel syndrome

“…Global Improvement will be assessed with the Global Improvement Scale ( GIS ) . This scale asks participants "Compared to the way you felt before you entered the study, have your IBS symptoms over the past 7 days been from (1) = substantially worse, to (7) = substantially improved [95]". Global improvement is noted for patients endorsing moderately or substantially improved status.…”

“…Global improvement is noted for patients endorsing moderately or substantially improved status. The scale shows adequate reliability and validity [95]. Global improvement, in addition to symptom severity, is recommended as a primary endpoint in IBS therapy trials [96].…”