Outcome measurement in clinical trials for ulcerative colitis: towards standardisation

Clinical trials determining the efficacy of new treatments need internationally agreed standardised endpoints. Only these allow studies to be compared and, importantly, combined for greater statistical power and a more reliable estimate of the benefits and harms of an intervention. Agreement on endpoints has been achieved for trials in rheumatology (Outcome Measures in Rheumatology, OMERACT [1]. OMERACT's consensual approach has been extremely successful and we feel that this approach now needs to be applied to trials of inflammatory bowel disease.In the field of gastroenterology there are many exciting new drugs in development, with great prospects for the treatment of ulcerative colitis in particular. International consensus on the endoscopic, clinical and histological scoring systems is essential as these are the key components used to determine entry criteria and outcome measurements in clinical trials of ulcerative colitis. As the aim of all clinical trials is to determine whether an intervention results in clinical response and/or remission, with an acceptable adverse event profile, an agreed definition of these parameters is paramount. Whereas in rheumatology joint space narrowing may be measured with simple radiography, in inflammatory bowel disease direct measures are more difficult and often involve endoscopy. In this paper we discuss the systems currently available and their limitations. We propose potential solutions, focussing in particular on the issue of interobserver variation in sigmoidoscopy.The multiplicity of clinical activity indices used for scoring ulcerative colitis has recently been comprehensively reviewed [2]. No less than seven different symptom-based activity scores, two composite scores, and four evaluation scoring systems have been used in ulcerative colitis [3-16] [Table 1]. The names of the indices also vary between different publications which exacerbates the confusion [Table 2]. The scores vary in the use of objective measurements