If the study is much larger or smaller than required to answer the primary research question, then the P value can be misleading on its own. P values are most useful in a setting where a trial was designed to have an appropriate sample size to address the primary objective of the study. It is always important to consider the clinical effect size and sample size when interpreting a P value. Garrett-Mayer: P values can have some value, but should not be interpreted on their own. What is their value in assessing clinical trial outcomes in oncology?ĭr. OncoTherapy Network: Statistical P values and their interpretation have become somewhat controversial. Garrett-Mayer about concerns regarding statistical probability (P) values and “data dredging” in clinical research.

She is a member of the American Society of Clinical Oncology (ASCO) Cancer Research Committee.

Professor of Biostatistics and Epidemiology Elizabeth Garrett-Mayer, PhD, is Director of Biostatistics at the Medical University of South Carolina’s Hollings Cancer Center in Charleston, South Carolina.

What is a data dredging