Where the interpretation of the interaction comes from? Let us assume that we have patients in out sample and a linear model (simple or mixed). For the linear model we have an equation of the form: Y=A0+A1*X1+A2*X2+A3*X1*X2, where A0 is the intercept and A1 and A2 are the main effects of X1 and X2 respectively. Read more about Interactions and why we all get them wrong?[…]

Let’s say we need to calculate a sample size for a single proportion estimation (testing). Omitting now maths and some variability in the used formulas we can do it two in two ways: First: using power of a single test and then we just require the test is rejecting or not the hypothesis of a Read more about Few thoughts about sample size calculation for a single proportion[…]