A Nonparametric Test for Independence of Time to Recurrence and Mode of Recurrence for Panel Count Data

Panel count data arise in situations when a recurrent event process can be examined only at a sequence of discrete time points. If the study subjects are exposed to recurrent events of several types, we obtain panel count data with multiple modes of recurrence. In this article, we propose a nonparametric test for independence of time to recurrence and the mode of recurrence for panel count data exposed to multiple modes of recurrence. Simulation studies are conducted to assess the performance of the proposed test in finite samples. We illustrate the practical utility of the procedure using two real-life data sets, one arising from a medical follow-up study on a skin cancer chemoprevention trial and the other from a warranty database for a fleet of automobiles.