Objectives: In patients with suspected Crohn's disease (CD), little is known about the test characteristics of capsule endoscopy (CE) in the diagnosis of this condition. We sought to determine the utility of CE for the subsequent diagnosis of CD in patients suspected to have this condition.
Methods: All patients who underwent CE at a single tertiary-care center for investigation of suspected small bowel CD, and who had a 12-month follow-up, were included in the study. All patients had undergone other investigations that were normal or equivocal. The test characteristics of CE were determined on the basis of capsule findings of small bowel ulcers and a subsequent new diagnosis of CD within 12 months of CE.
Results: The study included 102 patients with 12-month follow-up data. The majority (75%) met the established criteria to define "suspected Crohn's disease" as an indication for CE. Most had undergone computed tomography scan or small bowel follow-through (92%) and colonoscopy (99%) before CE. There were abnormal CE findings suggestive of CD in 39 patients. The prevalence rate of a new diagnosis of CD by 12 months in the study population was 13%. Using the presence of more than 3 ulcers as the criterion for an abnormal CE study, the sensitivity of CE for the diagnosis of CD was 77%, the specificity was 89%, the positive predictive value (PPV) was 50%, and the negative predictive value (NPV) was 96%.
Conclusions: In patients with suspected CD, CE has a high sensitivity and a NPV for this condition. The PPV varies depending on the patient population and the criteria for a CE diagnosis of CD.