Journal of Dental Research, Vol 58, 2080-2084, Copyright © 1979 by International & American Associations for Dental Research Online Journals
Ridit analysis in dental clinical studies
J. L. Fleiss, N. W. Chilton and S. Wallenstein
Ridit analysis is presented as an appropriate method of analyzing dental
clinical data which fall somewhere between the purely categorical (e.g.,
improved vs. not improved) and the bona fide quantitative (e.g., mg %
salivary calcium) scales of measurement. The key feature of the method is
the estimation of the probability that a randomly-selected patient from one
treatment group is "better-off" than a randomly-selected patient from
another. Methods are presented for testing statistical significance and
constructing confidence intervals. The method is illustrated on data from a
comparative clinical trial of ibuprofen, aspirin and placebo in the relief
of post-extraction pain. There were no significant differences in efficacy
among the active treatments, but each was significantly superior to
placebo.
