Statistical Significance and Clinical Relevance The Importance of Power in Clinical Trials

Statistical Significance and Clinical Relevance
The Importance of Power in Clinical Trials in Dermatology
Sachin S. Bhardwaj, MD; Fabian Camacho, MS; Amy Derrow, MS;
Alan B. Fleischer, Jr, MD; Steven R. Feldman, MD, PhD
W
hen evaluating the validity of a study, the reader must consider both the clinical
and statistical significance of the findings. A study that claims clinical relevance
may lack sufficient statistical significance to make a meaningful statement. Conversely, a study that shows a statistically significant difference in 2 treatment options may lack practicality. The concept of power of a clinical trial refers to the probability of detecting a difference between study groups when a true difference exists. We will discuss statistical
power by examining studies too small to identify important differences, studies so large as to identify differences that are not clinically significant, difficult-to-design studies without very large patient populations, and those studies with both adequate power and clinically relevant findings. Dermatologists should not focus on small P values alone to decide whether a treatment is clinically
useful; it is essential to consider the magnitude of treatment differences and the power of the study.
Arch Dermatol. 2004;140:1520-1523

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s