Hi all

I have data from a randomized trial that measures the effect of an intervention group (0/1) on a biomarker outcome measured at 3 time points (0hr, 12hr, 24hr). I have constructed the below model to assess whether there is any difference in change in the biomarker outcome over time by group. The biomarker is log transformed as it is not normally distributed.

mixed log_biomarker group##i.time || StudyID: studysite, cov(exch)

The output gives me a significant interaction effect at the 24 hour time point with a coefficient of 0.3 and p-value of 0.04.

I understand this means that there is a difference in the trajectory of the biomarker between group with respect to time. What I'm not clear on is how to report this coefficient. Is it fair to exponentiate it ~1.4 and say that a change in group results in a 40% difference in slope over time? Is there a way to use margins here?

Thanks in advance for any suggestions!