Tag Archives: Early stopping

PMean: Slapping the word “pilot” on a failed study

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, but the second arm had a dropout rate of 50%.

Anyway, they decided to end the study (good call!) and wanted to know what they should do with the data that they had already collected. There were three options that they were considering (I’m paraphrasing a bit here).

  1. Analyze the study as originally planned, including a classic test of hypothesis for the primary outcome.
  2. Call this a pilot study and provide descriptive analyses only.
  3. Recognize that the data is so fatally flawed that any analysis of the data would be inappropriate.

This is what I suggested. Continue reading

Recommended: Predicting clinical trial results based on announcements of interim analyses

If you’ve ever been involved with interim reviews of clinical trials on a DSMB (Data Safety and Monitoring Board), you will be warned about the importance of confidentiality. There are two big reasons for this. First, leaking of interim trial results could lead to insider trading. News that the trial is going well would lead to a jump in stock prices and news that the trial is going poorly would lead to a dip in stock prices. If someone gets early news from the DSMB, they could profit from that inside information. Continue reading