A non-parametric test for independence of time to failure and cause of failure for discrete competing risks data

Abstract

Competing risks data with discrete lifetime come up in practice. However, only limited literature exists for such data. In this paper, we propose a non-parametric test based on U-statistics for testing independence of time to failure and cause of failure of competing risks data when the lifetime is a discrete random variable. Asymptotic distribution of the proposed test statistic is derived. An extensive Monte Carlo simulation study is conducted to assess the finite sample performance of the proposed test. The flexibility of the testing procedure is illustrated using real data sets on oral cancer patients and drug-exposed pregnancies.

Keywords:

• Competing risks
• independence
• U-statistics

2010 Mathematics Subject Classification:

• 62G10

Acknowledgments

The authors thank the Associate Editor and anonymous referees for making valuable suggestions which led to a substantial improvement of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

E. P. Sreedevi would like to thank Kerala State Council for Science Technology and Environment for the financial support to carry out this research work.