Two-part models for cost with zeros to decompose effects of covariates on probability of cost, mean nonzero cost, and mean total cost.
Liu W, Grunwald GK, Ho PM. Two-part models for cost with zeros to decompose effects of covariates on probability of cost, mean nonzero cost, and mean total cost. Stat Med. 2019 07 10; 38(15):2767-2782.