“…Many nonparametric methods have been proposed (Prentice and Cai, 1992; Hsu and Prentice, 1996;Wang and Wells, 2000) over the past twenty years; however, most are subject to complicated estimation or interpretation. Recently, a number of authors (Fan et al, 2000; Bandeen-Roche and Ning, 2008; Cheng and Fine, 2008) have proposed nonparametric estimations of the local conditional hazards ratio (Oakes, 1989), an easily interpreted association measure. However, in this scenario, each association is assumed to be constant over finite time “bins”.…”