Predictive Value of Capsule Endoscopy for the Diagnosis of Crohnʼs Disease in a Symptomatic Population

Abstract

Purpose: Little is known about the characteristics of capsule endoscopy (CE) as a tool for diagnosing Crohn's disease in symptomatic patients. The aim of this study was to determine the positive predictive value of CE for the diagnosis of Crohn's disease Methods: All patients who underwent CE at a single tertiary care center for investigation of abdominal pain, diarrhea, or suspected Crohn's disease were included. Patients were excluded if they carried a previous diagnosis of Crohn's disease, were actively being treated for malignancy or had inadequate CE evaluations. Medical records were reviewed to determine demographic data, symptoms prompting evaluation, and workup prior to CE. The primary outcome of the study was the diagnosis of Crohn's disease within twelve months of CE. Results: The study included 102 patients with 12-month follow-up data. The mean age was 49.5 years (66% female). The indications for CE were abdominal pain (41%), diarrhea (14%), pain and diarrhea (41%) and suspected Crohn's disease (67%). NSAIDs were used in 27% of patients prior to CE. Most patients had undergone CT or SBFT (92%) and colonoscopy (99%) prior to CE. There were abnormal CE findings suggestive of Crohn's disease in 39 patients, including aphthous ulcers, erosions or inflammation. There was no significant difference in demographic characteristics or previous workup between patients who had an abnormal CE and normal CE. The prevalence of Crohn's disease in the study population was 13%. The sensitivity of CE for the diagnosis of Crohn's disease was 92%, the specificity was 71%, the positive predictive value was 32% and the negative predictive value was 98%. Analysis using strict criteria of “more than 3 ulcers” as the definition of an abnormal CE study improved the positive predictive value of CE to 52% (Table 1). Age < 30 (PPV 67%) and absence of NSAID use (PPV 42%) improved the predictive value of an abnormal test.Table: Test Characteristics of Capsule Endoscopy in Patients with Suspected Crohn's Disease According to Capsule Findings.Conclusion: The positive predictive value of an abnormal CE for the diagnosis of Crohn's disease ranges from 32% to 67% depending on the criteria used to define an abnormal test, and the population studied.