Skip to content

Cancer Health Center

Font Size

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.

      WebMD Public Information from the National Cancer Institute

      Last Updated: February 25, 2014
      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.
      1

      Today on WebMD

      Colorectal cancer cells
      A common one in both men and women.
      Lung cancer xray
      See it in pictures, plus read the facts.
       
      sauteed cherry tomatoes
      Fight cancer one plate at a time.
      Ovarian cancer illustration
      Do you know the symptoms?
       
      Jennifer Goodman Linn self-portrait
      Blog
      what is your cancer risk
      HEALTH CHECK
       
      colorectal cancer treatment advances
      Video
      breast cancer overview slideshow
      SLIDESHOW
       
      prostate cancer overview
      SLIDESHOW
      lung cancer overview slideshow
      SLIDESHOW
       
      ovarian cancer overview slideshow
      SLIDESHOW
      Actor Michael Douglas
      Article