Objective assessment of clinical disease activity

An objective assessment of disease activity is an important prerequisite to clinical trials establishing the efficacy of new drugs or treatment strategies. Furthermore, while new objectives are developed for the global management of inflammatory bowel disease, leading to new treatment strategies aiming at a tighter control of the disease, it becomes important to have available user-friendly tools adequate for disease activity quantification and helping the clinician in treatment decisions. In ulcerative colitis, clinical activity of the disease has been rather well correlated to endoscopic activity and a large number of indices including or not an endoscopic assessment have been developed for a specific use in clinical trials. The simpler amongst them, like the Mayo score are also adapted for routine practice. In Crohn’s disease, the Crohn’s disease activity index has almost been the unique index used in clinical trials for more than 30 years. However, due to its poor correlation to intestinal lesions assessed either by endoscopy or cross-sectional imaging it is now abandoned in pivotal clinical trial, being replaced by a combination of endoscopic assessment and patients reported symptoms. For everyday routine practice, a simple score mainly based on patient’s symptoms, like the Harvey Bradshaw index or close variants potentially recorded by the patient him/herself, seems appropriate.