PMean: Slapping the word pilot on a failed study

Steve Simon


Someone was asking on the MedStats listserv about a study that had gone off the rails. They had recruited only about a third of the patients that they had wanted. Things were going pretty well in the first arm of the study


  1. Analyze the study as originally planned
  1. Call this a pilot study and provide descriptive analyses only.
  2. Recognize that the data is so fatally flawed that any analysis of the data would be inappropriate.

This is what I suggested.

If you stop a study early because of reasons that are related to the p-value that you are seeing

If you stop a study for other reasons

Stopping because of a very high dropout rate could be a problem

If you are a stickler for accuracy

So go ahead and analyze the data.

But please

There are too many people who can’t afford to run a good study and know that it is way under-powered