Superiority vs. Equivalence vs. Non-inferiority

The terms superiority, equivalence and non-inferiority are used frequently in publications on clinical trials. To someone starting out in clinical research these three terms and their precise meaning can be quite difficult to grasp. Indeed even experienced researchers have trouble getting their h

Why is Sample Size important?

A good statistical study is one that is well designed and leads to valid conclusions. This however, is not always the case, even in published studies. In Cohen’s (1962) seminal power analysis of the journal of Abnormal and Social Psychology he concluded that over half of the published studies w

Power & Sample Size for Group Sequential Trials – Announcing nTerim

Statistical Solutions is delighted to announce the latest statistical package to add to our portfolio, nTerim – Power and Sample Size for Group Sequential Trials.

Here are a taste of nTerim’s main features

Power and Sample Size calculations for Two Means test, Two Propo