Gianluca Baio from University College London has just published a new R library called BCEs0 that is specifically designed to run a full Bayesian cost-effectiveness analysis of individual data in the presence of structural zero costs for some subjects. He has previously written other Bayesian CEA code that we featured on the blog.
The package implements a framework developed previously. The framework assumes that data are available for n0 and n1 subjects, that are respectively given some treatment t0 and t1. Typically, costs and clinical benefits should be modelled assuming some form of correlation. But in the case of structural zeros, the model gets even more complicated, since the population average costs need to be computed accounting for the fact that there are two "components" in the population - one made by the individuals who actually accrue some positive cost and the other by the subjects that have no cost.