This post presents an *R* function to implement the sample size estimation presented in Twisk (2013) for **continuous outcomes**.

Formula 11.1 is used when the researcher wants to compare two groups at one single point in time (e.g., placebo versus treatment at post-intervention), whereas Formula 11.3 is used when there is more than one follow-up measurement and the researcher is interested in comparing the two groups based on the average in the outcome variable over the **total follow-up period**.

Continue reading “Sample size estimation for balanced randomised control trials”