Understanding Determinants of Patient Preferences Between Stool Tests and Colonoscopy for the Assessment of Disease Activity in Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Evidence is now available in support of using fecal biomarkers to monitor disease activity in inflammatory bowel disease (IBD). Patient adherence is often cited as a barrier to implementation. We assessed patient determinants for using stool tests to monitor disease activity.
METHODS: Prospective interview of IBD patients using an analytic hierarchy matrix survey built to understand preferences for choosing between stool testing or colonoscopy for monitoring disease activity, after considering different test criteria (accuracy, preparation, pain, complications). Theoretical thresholds of misclassification were posed to patients to see how they might consider shifting from colonoscopy to stool testing.
RESULTS: A total of 100 patients (n = 51 CD, n = 46 male) were interviewed with median age and disease duration of 44 years (IQR 27-63) and 9 years (IQR 5-21), respectively. Stool-based testing was preferred over colonoscopy by 60% initially; however, a majority of participants changed their choice to colonoscopy after learning more about the diagnostic performance of currently available stool tests for disease monitoring (p < 0.001). Across all sub-groups, accuracy was ranked as the top criterion when choosing between stool-based testing and colonoscopy for disease activity assessments. Most patients were willing to choose stool-based testing over colonoscopy for disease monitoring if the stool test was wrong at most 1 in 20 times (5% misclassification rate). DISCUSSION: Accuracy is the most important criteria for IBD patients when choosing monitoring strategies, and a high degree of confidence is required of stool test results for patients to choose this strategy.