INTRODUCTION  Comparative effectiveness research (CER) is an emerging field that compares the relative effectiveness of alternative strategies to prevent, diagnose, or treat patients that are typical of day-to- day clinical practice.  In 2009 the Institute of Medicine (IOM) published a priority list for CER for all of medicine.  To assist the field of IBD in CER it is necessary to develop priorities specific to Crohn’s and colitis. AIM  To develop a priority list of CER studies for IBD. METHODS  Following the IOM's approach for developing CER priorities, we surveyed practicing GIs to determine their most important CER topics in IBD.  The survey was electronically distributed to an international sample of GIs from the membership of:  American College of Gastroenterology  Canadian Association of Gastroenterology  Australian IBD Association  British Society of Gastroenterology  In addition, an international panel of 13 IBD experts (BRIDGe group) independently proposed CER studies.  Two patient focus groups were convened to determine their opinions of the most important IBD research topics.  All candidate CER studies were compiled into 21 topic categories.  CER studies were presented to the expert panel using the validated RAND/UCLA method.  Rated using a standard 1-9 point scale (1=lowest priority; 9=highest; >7=high priority).  Following the initial ratings the panel met in person to re-rate priorities after group discussion.  Disagreement was assessed using a validated index. Setting Priorities For Comparative Effectiveness Research In IBD: Results Of An International Provider Survey, Expert RAND Panel, And Patient Focus Groups Setting Priorities For Comparative Effectiveness Research In IBD: Results Of An International Provider Survey, Expert RAND Panel, And Patient Focus Groups A. Cheifetz 1, G. Melmed 2, B. Spiegel 3, J. Talley 4, S. Devlin 5, L. Harrell 6, P. Irving 7,*, J. Jones 8, G. Kaplan 5, P. Kozuch 9, M. Sparrow 10, F. Velayos 11, L. Baidoo 12,B. Bressler 13, C. Siegel 14 1 Beth Israel Deaconess Medical Center, Boston, MA 2 Cedars-Sinai Medical Center, 3 VA Greater Los Angeles Healthcare System, 4 CURE Digestive Disease Research Center, Los Angeles, CA, 5 University of Calgary, Calgary, Canada, 6 University of Chicago, Chicago, IL, 7 Guy's and St. Thomas' Hospitals, London, United Kingdom, 8 University of Saskatchewan, Saskatoon, Canada, 9 Jefferson University, Philadelphia, PA, 10 The Alfred Hospital, Melbourne, Australia, 11 University of California San Francisco, San Francisco, CA 12 University of Pittsburgh, Pittsburgh, PA, 13 University of British Columbia, Vancouver, Canada, 14 Dartmouth-Hitchcock Medical Center, Lebanon, NH CONCLUSIONS  We systematically developed a list of high priority CERs for IBD based on a survey of GIs, expert review, and patient input.  This list can guide IBD researchers and funding agencies towards the most important CERs. RESULTS  234 unique CER questions.  Based on the initial round of ranking and clinical relevance, the RAND panel selected 87 CER questions to re-rate in person.  40 were rated as high priority.  Disagreement was observed in only 5 of 87 CER questions.  The panel then distributed points to the highest rated CER questions to develop the top 10 CER priorities for IBD. Top 10 Comparative Effectiveness Research Priorities Compare the effectiveness of… The panel meeting was supported by an unrestricted grant from Warner Chilcott, Abbott, and Shire. Unrestricted funding for the BRIDGe group is provided by Abbott, UCB, Salix and Warner Chilcott. Withdrawal of biologic therapy vs. withdrawal of immunomodulator therapy vs. continued combination therapy in Crohn’s disease patients who achieved remission on combination therapy Efficacy and safety of infliximab vs. cyclosporine vs. surgery in hospitalized steroid-refractory ulcerative colitis Using biomarkers (genetics, immunology) vs. standard of care in predicting response and toxicity to therapy of IBD Different TNF inhibitors for the induction and maintenance of remission and mucosal healing in Crohn's disease 6MP versus anti-TNF agents in preventing clinical and endoscopic post-op recurrence of Crohn's disease after resection Anti-TNF alone versus anti-TNF+6MP in patients with moderate to severe Crohn's disease failing 6MP Scheduled post-operative colonoscopy vs. clinical follow- up guiding post-operative management Tailoring therapy to mucosal healing vs. standard clinical factors on long-term outcomes in IBD Standard anti-TNF dosing vs. trough-level anti-TNF dosing in IBD The efficacy and safety of long-term immunomodulation (6MP/AZA) versus biologic (anti-TNF) therapy in Crohn's disease and UC