Estimated changes of ADAS-cog compared to baseline using a random effects model. Higher scores indicate greater deficits. The solid lines represent effect estimates from a model with an interaction term for time and group, i.e. where the group effect can change over time. The dashed lines indicate a model without interaction. In this case, the group effect is forced to stay constant (as can be seen from the parallel, dashed lines from month 12 to month 22).
Luttenberger et al. BMC Neurology 2012 12:151 doi:10.1186/1471-2377-12-151