Blog 27 – Estimands Part 3B – What Is the ITT Estimand Anyway?

It is difficult to define the intention-to-treat (ITT) effect, and thereby the ITT estimand, since the use of the ITT approach can involve treating patients with many different treatments for many different time periods. Because of this mixture of treatment effects, the ITT approach is more of a HOW for analyzing data, than a WHAT for defining the treatment effect of interest.