  We conduct a review to assess how the simulation of repeated or recurrent
events are planned. For such multivariate time-to-events, it is well
established that the underlying mechanism is likely to be complex and to
involve in particular both heterogeneity in the population and
event-dependence. In this respect, we particularly focused on these two
dimensions of events dynamic when mimicking actual data. Next, we investigate
whether the processes generated in the simulation studies have similar
properties to those expected in the clinical data of interest. Finally we
describe a simulation scheme for generating data according to the timescale of
choice (gap time/ calendar) and to whether heterogeneity and/or
event-dependence are to be considered. The main finding is that
event-dependence is less widely considered in simulation studies than
heterogeneity. This is unfortunate since the occurrence of an event may alter
the risk of occurrence of new events.
