Responsiveness of the Work Productivity and Activity Impairment Questionnaire for Irritable Bowel Syndrome with Constipation (WPAI:IBS-C) to Clinically Meaningful Change

Abstract

Objective: The work productivity and activity impairment measures of the Work Productivity and Activity Impairment questionnaire for irritable bowel syndrome (WPAI:IBS) have been shown to discriminate among patients with different disease severity. The purpose of this investigation was to test the responsiveness of these measures to clinically meaningful changes in symptom severity among IBS patients with constipation (IBS-C) Methods: Female patients (18‐65 years old) who met Rome II criteria for IBS, excluding those with frequent diarrhea, were assessed during a randomized, double-blind, placebo-controlled, multicenter study of tegaserod 6 mg b.i.d. or placebo for 4 weeks. Absenteeism, presenteeism, overall work productivity loss, and activity impairment due to IBS symptoms during the previous 7 days were measured with the WPAI:IBS-C, which excludes diarrhea as an IBS symptom. Patients were classified as responders at Week 4 if they reported satisfactory relief of abdominal discomfort/pain, or relief of overall IBS symptoms in at least 3 of the 4 treatment weeks. The association between WPAI:IBS-C scores and responder status was tested using a Cochran-Mantel-Haenszel test stratified by treatment group Results: A total of 2,660 women were randomized and of these 1,675 (tegaserod [n=1,363], placebo [n=312]) were employed and completed WPAI:IBS-C questionnaires. At Week 4, compared to non-responders, responders with relief in abdominal discomfort/pain reported significant reductions in absenteeism (p=0.02), presenteeism (p<0.0001), overall work productivity loss (p<0.0001), and activity impairment (p<0.0001). When overall IBS symptom relief was considered, compared with non-responders, responders reported significant reductions in all measures (p<0.0001), except absenteeism where the reduction was not significant Conclusion: The WPAI:IBS-C work productivity and activity impairment measures are responsive to clinically meaningful change in IBS symptom severity and are useful tools for measuring outcomes in IBS-C l The Work Productivity and Activity Impairment questionnaire for IBS (WPAI:IBS) measures absenteeism, presenteeism, overall work productivity loss (absenteeism plus presenteeism), and daily activity impairment due to IBS symptoms during the previous 7 days 3