@JeromyAnglim, thanks for your answer to "How to determine the sample size needed for repeated measurement ANOVA". My question: Is there a formula to estimate the minimum number of time points required for repeated measurements when we do a clinical trial? I know that there's a formula to estimate the sample size when we plan to do a clinical trial; I'm hoping for something like that.
I am now planning to do a clinical trial to evaluate the effect of a new device compared to the old one. The patients will be randomized 2:1 to a study arm or controlled arm. My outcome variable is continuous. If the study is conducted over 1 year, I want to know what is the minimum number of time points I should get? Could you give me some reference?
