Several activity indices have been developed to assess the efficacy of
new therapies for inflammatory bowel disease. The ideal index should
be simple to administer and quantitative. It should be a composite of
subjective symptoms, objective findings and laboratory markers of infl
ammation. Any newly developed indices should be assessed for validity,
reliability and responsiveness before application in clinical trials.
Obstacles to standardizing disease activity relate to the heterogenei
ty of disease manifestations, the characteristics of the study populat
ion, the therapy being tested, the investigators' preference for which
index to apply and the attributes of the index. Examples of available
indices are identified, some of their limitations are discussed, and
guidelines for how to select an index for a clinical trial are outline
d.