Recurrent Events

In many biomedical studies, subjects may experience the outcome of interest more than once over a period of observation; outcomes of this sort have been termed recurrent events. For example, patients with cerebrovascular disease may experience repeated transient ischemic attacks, and HIV patients may experience recurrent opportunistic infections. Other examples of recurrent events include infections, myocardial infarctions, tumor metastases, and disease relapses/remissions. The structure of recurrent events is that of naturally ordered failure time data, and the different events “within” an individual are correlated. These types of processes arise frequently in medical studies, where information is available on many individuals, each of whom may experience transient clinical events repeatedly over a period of time. For instance, asthma is occurring more and more frequently in very ...