I am looking for a non-parametric version of the multivariate repeated measures GLM procedure.
I have ordered symptoms of a disease at 2 time points (0-3), and I want to show that they change differentially (in response to something that happens to the whole sample during the 2 time points). If my symptoms were metric, I could run a multivariate repeated measures GLM, and if the interaction term symptom*time is significant, I have differential change of symptoms over time.
The Friedman test - a non-parametric version of the repeated measure GLM - does not suffice, because it can either compare medians of multiple DVs at the same time, or medians of the same DV over time, but it cannot handle multivariate + repeated measure (at least I haven't found a way to do that).
Software I have installed and can work with is R, SPSS, and MPLUS available. Thank you.