CRN noted that careful analysis of the study reveals the study showed no effects beyond random variations in response and that the researchers based their conclusions on statistically insignificant data.
"In fact, the actual data showed no difference in artery blockage between the antioxidant group and the control group, even after the researchers arbitrarily created 'worst-case' numerical values to fill missing data points," stated John Hathcock, Ph.D., vice president, nutritional and regulatory science, CRN. "Even those statistics that would appear to be significant are, in actuality, the exact pattern that would randomly occur if no treatments had been administered, and as the authors have stated, this could be a 'chance finding.'"
Further scrutiny exposes flaws in the study's design. For example, the study groups were not stratified to assure that all the treatment groups were similar with respect to the degree of coronary artery blockage. In addition, the authors concede that their study was powered only to detect the degree of blockage of the arteries, not the differences in clinical outcomes. Yet much of their discussion focuses on comparisons of clinical outcomes.
The authors of the WAVE study asserted that the results of the Heart Protection Study (HPS) provided support to their conclusions by identifying "a trend toward an increase in mortality" in the vitamin group. However, the authors of the HPS actually reported "no significant differences" in mortality. (Lancet 2002; 360:23-33.)
Dr. Hathcock noted that there is broad scientific consensus that dietary supplemen
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19-Nov-2002