I intend to quantify the relative impact of one variable (with 3 intrinsic grades on a scale from 1-3) on the dependent variable that lies between 0 and 1 (it is a ratio). My patient sample is extremely small (3 patients). However, of each patient, several measures were taken at different time points (total number of dat a points is 21).

I was told that linear mixed models would be a great way to basically compare means between the groups and say whether there is a difference in-between the grouping or not.

However, the estimated marginal means are estimated to lie above 1, which is impossible (maximum value for my dependent variable would be 1).

If the estimated mean is above one, is it correct to just adjust it to 1?

Is there a better way to achieve what I want to show?

Would much appreciate your help!

Thank you!