Stomp On Step 1 , hi, when you r givin example for confounder, you mentioned that the treatment group is in 75 and placebo group is in 25, but later on you also state that because of the treatment group is much younger than the placebo group, thus the outcome is better...(the previous and the latter is different)...
***** You are right. I flipped it when I first said it. I was trying to say that the treatment group is young and the placebo group is old. This would make the results for the treatment look really good, but really it is just the case that younger people tend to be healthier
Health Support Thanks for the comment and good luck studying! Crossover Studies are experimental studies that have the participants “switch groups” part way through the study. Patients that start with the placebo switch to getting the treatment halfway through the study while those that started with the treatment get the placebo after the halfway point. So each participant gets the placebo for a while and the treatment for a while. In this study design there is no separate control group as participants act as their own controls. Parallel studies are what you think of as a "regular" study. The total study population is split into the placebo and treatment group. The treatment group gets the "real" treatment for the entire study and the placebo group gets the placebo for the entire study. Here the placebo group acts as the control group. Does that make sense?