In this paper, we present a model for imputing timing of mother-to- child transmission (MTCT) of HIV. The method re ects the three modes of MTCT of HIV: in utero, during delivery and via breastfeeding and can accomodate shapes for the baseline hazard that vary between infants. Ad- ditionally, it allows that the majority of infants do not experience MTCT of HIV. Final analyses from the imputed data sets are combined in a mul- tiple imputation framework. The methods is illustrated on a large trial designed to assess the use of antibiotics in preventing MTCT of HIV and is validated using simulations. Additionally, we explore appropriate censoring techniques to account for weaning.


Survival Analysis