In analyzing the outcomes of such trials, researchers should take into account any similarities among group members or any common influences affecting the members of the same group, Murray said. But too often, this review found that the common ground among group members was not factored into the final statistical analysis.
What can result is called a Type 1 error, when a difference between outcomes in groups is found that doesnt really exist.
In science, generally, we allow for being wrong 5 percent of the time. If you use the wrong analysis methods with this kind of study, you might be wrong half the time. Were not going to advance science if were wrong half the time, said Murray, also a member of the Cancer Control Program in Ohio States Comprehensive Cancer Center.
The review identified 75 articles published in 41 journals that reported intervention results based on group-randomized trials related to cancer or cancer risk factors from 2002 to 2006. Thirty-four of the articles, or 45 percent, reported the use of appropriate methods used to analyze the results. Twenty-six articles, or 35 percent, reported only inappropriate methods were used in the statistical analysis. Eight percent of the articles used a combination of appropriate and inappropriate methods, and nine articles had insufficient information to even judge whether the analytic methods were appropriate or not.
Am I surprised by these findings" No, because we have done reviews in other areas and have seen similar patterns, Murray said. Its not worse in cancer than anywhere else, but its also not better. What were tryi
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Ohio State University