649 Multiplex Polymerase Chain Reaction-Based Stool Testing Results in Less Endoscopy in Outpatients With Inflammatory Bowel Disease Compared to Conventional Stool Testing

Abstract

INTRODUCTION: Patients with inflammatory bowel disease (IBD) frequently receive stool testing for exacerbations in gastrointestinal symptoms. Multiplex polymerase chain reaction-based gastrointestinal pathogen panels (GI PCR) offer significant benefits in sensitivity over conventional tests such as culture and ova and parasites exam. However, it is unclear how additional pathogen positive findings by GI PCR affect further clinical management. In this study we compared the downstream healthcare utilization of IBD patients who received GI PCR to conventional stool testing. METHODS: We reviewed outpatients presenting to an academic medical center with an acute episode of diarrhea from September 2015 to February 2019 to identify patients with IBD who received stool testing with a FilmArray GI PCR or stool culture and ova and parasite exam (conventional testing). All patients received isolated PCR testing for Clostridium difficile. Each GI PCR patient was randomly matched with a conventional testing patient based on age, sex, and date of testing. Post-visit endoscopy, abdominal radiology, antibiotic therapy, and escalation in IBD medical therapy defined as an increase in the dose of a prior medication or prescription of a new medication were recorded. Long-term outcomes including emergency room (ER) visits, hospitalizations, and abdominal surgery were recorded as well. T-test and Chi-square analysis were used to compare outcomes between groups. RESULTS: Among 1,104 patients receiving stool testing, we identified 120 outpatients with IBD, of whom 26 (22%) received conventional stool testing and 94 (78%) GI PCR testing. Of 26 patients with conventional testing, 1 (4%) had a pathogen identified on testing while 36 (38%) of 94 GI PCR patients had positive tests (Table 2). There were no significant differences in demographics, IBD characteristics, rates of C. difficile infection, and behavioral risk factors between groups (P > 0.05). GI PCR patients were less likely to receive any endoscopic exam in the 30-day period after their initial visit (20% vs. 42%, P = 0.021). There were no significant differences in exposure to radiology, antibiotics, escalation of IBD therapy, or long-term IBD outcomes (P > 0.05). CONCLUSION: Testing with GI PCR was associated with lower rates of post-visit endoscopywith no differences in long-term outcomes in outpatients with IBD. This study suggests that in certain populations of patients, GI PCR testing has the potential to reduce downstream healthcare utilization and management burden.