Statistical approaches to uncertainty: P values and confidence intervals unpacked

Editor's comment

In March 2007, Equine Veterinary Journal reproduced from Evidence Based Medicine a summary defining measures of association as used to address therapy, harm and aetiology questions. In this companion article, the concept of uncertainty is discussed. The P value is familiar to all of us who read Equine Veterinary Journal and, to some extent, it could be said that familiarity may have engendered a degree of contempt. For clinicians, the issue revolves around the difference between clinical significance and statistical significance. In the article below, these concepts are demystified to show how research evidence can enhance our clinical practice if clinical and statistical significance are reported and considered separately.

C. M. M.