Defining partial response in inflammatory bowel disease: a Delphi consensus and economic evaluation.

Background: Therapeutic goals in inflammatory bowel disease (IBD) are constantly evolving due to novel medical options and diagnostic tools, yet unmet clinical needs persist.

Objectives: We aimed to establish a consensus definition for partial responders in clinical practice, considered as patients failing to meet defined objectives within the desired time frame.

Design: A two-round Delphi consultation was held with IBD-specialized gastroenterologists.

Methods: The 22-item questionnaire covered four clinical scenarios: (1) moderate ulcerative colitis (UC); (2) acute severe UC; (3) luminal Crohn's disease (CD); and (4) perianal CD. Consensus was defined when ⩾70% of panellists agreed with a statement, rated using a 7-point Likert scale. We also analysed the associated annual costs for partial responders and patients in remission according to the agreed long-term definitions, based on a literature review and the experience of the scientific committee. Medication costs were excluded from the analysis.

Results: Sixty Spanish gastroenterologists with extensive experience in IBD management participated in the consultation. Consensus was achieved on partial response definitions with different criteria over time, including clinical scores, biomarkers and imaging or endoscopic examinations. The annual cost for partial responders and patients in remission was estimated at €2570.40 and €820.20 for UC, €1607.30 and €718.0 for luminal CD and €2886.70 and €888.80 for perianal CD, respectively.

Conclusion: The concept of partial responders has been defined in four clinical scenarios. Patients achieving prolonged remission could provide 55%-70% savings in non-pharmacological resource use and associated costs. Our study could help healthcare professionals in decision-making, ultimately improving patient care.