  In some settings involving recurrent events, the occurrence of one event may
produce a temporary increase in the event intensity; we refer to this
phenomenon as a transient carryover effect. This paper provides models and
tests for carryover effect. Motivation for our work comes from events
associated with chronic health conditions, and we consider two studies
involving asthma attacks in children in some detail. We consider how carryover
effects can be modeled and assessed, and note some difficulties in the context
of heterogeneous groups of individuals. We give a simple intuitive test for no
carryover effect and examine its properties. In addition, we demonstrate the
need for detailed modeling in trying to deconstruct the dynamics of recurrent
events.
