Validation of the bowel urgency numeric rating scale in patients with Crohn's disease: results from a mixed methods study

PurposeBowel urgency (BU) is an important symptom of Crohn's disease (CD), however there is no patient-reported outcome (PRO) scale validated in this population to assess BU severity. Here we evaluated the content validity and psychometric properties of the Urgency Numeric Rating Scale (NRS).MethodQualitative interviews were conducted with moderate-to-severe CD participants to confirm importance and relevance of BU in this population, cognitively debrief the Urgency NRS, and explore score interpretation and CD remission. A quantitative web survey study was conducted to explore the measurement properties of the urgency NRS.ResultsQualitative Interview: 34 of 35 participants reported BU. It was most bothersome for 44%, 47% reported it daily, 18% with every bowel movement. BU had a severe impact on daily activities, causing many participants to stay home more than preferred. Patients confirmed the relevance, appropriateness, comprehensibility of the item, recall period, response options, and instructions of the Urgency NRS. Small reductions on the Urgency NRS score reflected meaningful improvements. Quantitative survey: The study sample comprised 76 participants (65.8% female). Mean Urgency NRS score was 4.7 (SD 2.26; N = 76) at Week 1, with no floor/ceiling effect. Test-retest reliability was acceptable. Construct and known-groups validity against selected PROs were overall strong and within ranges hypothesized a priori.ConclusionThe Urgency NRS is a valid and reliable instrument to assess BU severity in CD.