Isotontic regression for interval censored survival data using an e-m algorithm

Abstract

This paper develops a nonparametric model of the relationship between survival S and a dichotomous random variable X under the order constraint that P(X=1|S=s) is increasing (or decreasing) with s. The estimation procedure, called isotonic regression, has been studied in some depth for the case of uncensored data, but we give a methodology which is appropriate in the more general context of right, left, and interval censored data. An E-M Algorithm (Dempster et. al., 1977) is used for maximum likelihood estimation.

Keywords:

• nonparametric
• isotonic regression
• order constraint
• left censored
• interval censored
• carcinogenicity
• E-M algorithm
• marinnun likelihood
• survival data