Modern pain research acknowledges the subjective and complex nature of pain that complicates its assessment. Furthermore, ethical imperatives place constraints on the comparative control to serve the in evaluation of a novel analgesic intervention (Silverman, O'Connor et al. 1993). One of the solutions to this issue, using normalized ordinal evaluations of pain and analgesic drug consumption around a central value in a manner that also accounts for changes in analgesic drug requirements (Silverman, O'Connor et al. 1993) will serve for direct assessment of the study hypothesis.