I have a set of 12 subjects: 6 administred with drug A and 6 with drug B. For each subject two time-points have been collected (before and after drug treatment) for each analyte (over 6000). I had a read around and it seems that mixed ANOVA suits my needs. Therefore I performed it using R as recommended on http://www.cookbook-r.com/Statistical_analysis/ANOVA/#mixed-design-anova Which is to say:
funAV <- function(x) aov(x ~ Class*time+ Error(Subjects/time),data=X) aovOb <- apply(X[,-(1:3)],2,funAV)
Once I get the results I have for each analyte a significant (or not significant) difference concerning Class (A or B), time (before or after) or a combination of both. On https://statistics.laerd.com/spss-tutorials/mixed-anova-using-spss-statistics.php it is reported that there is no need for a post hoc analysis with a 2 level factor between subjects. If this is true and I find a Class effect how can I know if the difference lies at time before or after? The same is true on the other way round i.e. if I find a time effect how can I know if the difference lies at drug A or B? I looked for post hoc analysis methods anywhere but all I could get was a bunch of methods for repeated measures ANOVA which is not exactly my case since I have an additional factor (the drug). Many thanks.