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Levels of Evidence for Adult and Pediatric Cancer Treatment Studies (PDQ®): Treatment - Health Professional Information [NCI] - Summary

Because studies or clinical experiences are ranked both by strength of design and importance of endpoint, a given study would have a two-tiered ranking (e.g., 1iiA for a nonblinded randomized study showing a favorable outcome in overall survival and 3iiiDiv for a phase II trial of selected patients with response rate as the outcome). In addition, all recommendations must take into account other issues that cannot be so easily quantified, such as toxicity, width of confidence intervals of observations, trial size, quality assurance in the trial, and cost. Nevertheless, the PDQ ranking system provides an ordinal categorization of strength of evidence as a starting point for discussions of study results.

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

WebMD Public Information from the National Cancer Institute

Last Updated: 8/, 015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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