Tutorials in clinical research, part VI: descriptive statistics.

OBJECTIVES

This is the sixth in a series of Tutorials in Clinical Research. The objectives of this tutorial are to produce a brief, step-by-step, user-friendly atlas with clinical scenarios and illustrative examples to serve as ready references and, it is hoped, to open an inviting door to understanding statistics.

STUDY DESIGN

Tutorial.

METHODS

The authors met weekly for 6 months discussing clinical research articles and the applied statistics. Liberal use of reference texts and discussion focused on constructing a tutorial that is factual as well as easy to read and understand.

RESULTS

The tutorial is organized into five sections: Overview, Key to Descriptive Summaries, Steps in Summarizing Descriptive Data, Understanding the Summaries of Specific Data Types, and Understanding Scope or Dispersion of Data.

CONCLUSIONS

Assessing the validity of medical studies requires a working knowledge of statistics; however, obtaining this knowledge need not be beyond the ability of the busy surgeon. Desire is the only limiting factor. We have tried to construct an accurate, basic, easy-to-read-and-apply introduction to the task of summarizing the characteristics of a single variable. This is known as descriptive statistics.