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STATISTICS IN MEDICINEStatist. Med. 2002; 21:1663–1680 (DOI: 10.1002/sim.1110)Commentary on‘Using inverse weighting and predictive inference to estimatethe ects of time-varying treatments on the discrete-timehazard’∗;†James M. RobinsDepartments of Epidemiology and Biostatistics; Harvard School of Public Health; 677 Huntington Avenue;Boston; MA 02115-6096; U.S.A.1. INTRODUCTIONI would like to begin by thanking the editor Ralph D’Agostino for his recognition of theimportance of the topic considered in Dawson and Lavori’s paper and for inviting this com-mentary. Dawson and Lavori (DL) propose several methods for estimating the ect of amonotone treatment pattern on the hazard function of a discrete failure time variable andcompare their approaches to others previously proposed. In my opinion, DL’s methods intheir Sections 1–3 are interesting and correct but are not the best available. However, I be-lieve the methods DL propose in Sections 4 and 5 are biased without the addition of further,rather implausible, assumptions. Additionally, I feel that certain of DL comments indicatethey are not fully aware of the motivation for and the range of the dirent methods pro-posedbymyselfandcolleagues.Mycommentaryisorganizedasfollows.IstreviewDL’smethodological proposals in the order in which they appear in their paper and compare otherproposals with theirs. In my al section, I review DL’s critique of methodologies proposedby myself and co-authors.2. IGNORABLE ...