Title: A general class of quasi-independence tests for left-truncated right-censored data,
Abstract: In survival studies, classical inferences for left-truncated data require
quasi-independence, a property that the joint density of truncation time and
failure time is factorizable into their marginal densities in the observable
region. The quasi-independence hypothesis is testable; many authors have
developed tests for left-truncated data with or without right-censoring. In
this paper, we propose a class of test statistics for testing the
quasi-independence which unifies the existing methods and generates new useful
statistics such as conditional Spearman's rank correlation coefficient.
Asymptotic normality of the proposed class of statistics is given. We show that
a new set of tests can be powerful under certain alternatives by theoretical
and empirical power comparison.