WASHINGTON — Endoscopy is an invasive procedure that patients don't like, and it may not be necessary for the evaluation of ulcerative colitis, Peter Higgins, M.D., said at the Clinical Research 2005 meeting.
In a study of 66 consecutive adult ulcerative colitis (UC) patients, results from two noninvasive indices overlapped significantly with results from invasive indices, said Dr. Higgins of the University of Michigan, Ann Arbor, and his colleagues. Regular use of noninvasive indices to assess UC could lower costs and encourage more patients to participate in clinical trials, he noted.
The investigators compared invasive and noninvasive indices in terms of how well each measured disease remission and other clinically important outcomes. The invasive indices used were the St. Mark's Index and the Ulcerative Colitis Disease Activity Index (UCDAI), and the noninvasive indices were the Simple Clinical Colitis Activity Index (SCCAI) and the Seo index. In addition, the doctors simply asked patients whether their disease was in remission.
Other indices are available in addition to those used in this study, Dr. Higgins said. “The problem is that none of them are validated, and none of them work that well.”
The investigators measured the correlations between the various indices to determine whether the noninvasive tests could provide similar information to that provided by the invasive tests. The two noninvasive indices, SCCAI and Seo, correlated well with the invasive St. Mark's index, with correlations of 0.86 for the SCCAI and 0.70 for Seo.
When the two invasive indices were compared with each other, the UCDAI endoscopy item predicted only 0.04% of the variance in the St. Mark's index after adjustment for the three noninvasive items on the UCDAI index.
Overall, endoscopy contributed very little to the assessment—significantly less than the 10% that Dr. Higgins expected. “We may not need endoscopy” to evaluate UC patients, he said. One explanation for endoscopy's minor role might be that other items on the same scale have measured the same factors, which would make endoscopy redundant.
Dr. Higgins concluded that noninvasive indices could effectively predict remission. “We're not losing much by leaving out endoscopy,” he said. The clinical practice of treating patients based on their reported symptoms is appropriate, and clinicians are correct to avoid rushing to scope.
“If the patient tells you they have 10 bloody stools, they are having a flare,” he said at the meeting, sponsored by the American Federation for Medical Research.