HTEBayes

In this repository, we provide the code for the function and simulation study of the paper "Confounder-Dependent Bayesian Mixture Model: Characterizing Heterogeneity of Causal Effects in Air Pollution Epidemiology" by D. Zorzetto, F.J. Bargagli-Stoffi, A. Canale, and F. Dominici, Biometrics, Volume 80, Issue 2, 2024.

Examples:

Load functions: R source("src/functions_simulations.R") source("src/model_CDBMM.R") Information for simulation data: ```R

sample size

n = 500

set seed

seed = 1 Parameters for the model: R

iterations

R = 3000 R_burnin = 2000

number of maximum groups for the two treatment levels

L0 = 20 L1 = 20 ```

Example 1 (3 groups)

Generation dataset and estimation CDBMM: ```R dataset <- simulationsample3groups(seed=seed, eta0=c(2,4,6), eta1=c(0,3,6), sigma0=rep(0.3,3), sigma1=rep(0.3,3), n=n)

cdbmmresults <- CDBMMGibbs(c=1, data_sample=list(dataset), n=n) ```

Visualize ITEs and GATEs for discovered groups: ```R hist(cdbmm_results$tau, nclass = 50, main = "ITEs")

groupallocation<-paste0(cdbmmresults$partition[,1],"-",cdbmm_results$partition[,1])

sapply(unique(groupallocation), function(g) cdbmmresults$atoms$p1[as.integer(substr(g, 3, 3))]- cdbmmresults$atoms$p_0[as.integer(substr(g, 1, 1))]) ```

Example 2 (5 groups)

Generation dataset and estimation CDBMM: ```R dataset <- simulationsample5cov(seed=seed, eta0=c(2,2,3,4.5,6.5), eta1=c(0,1,2.5,5,7.5), sigma0=rep(0.2,5), sigma1=rep(0.2,5), n=n)

cdbmmresults <- CDBMMGibbs(c=1, datasample=list(dataset), n=n) Visualize ITEs and GATEs for discovered groups: R hist(cdbmmresults$tau, nclass = 50, main = "ITEs")

groupallocation<-paste0(cdbmmresults$partition[,1],"-",cdbmm_results$partition[,1])

sapply(unique(groupallocation), function(g) cdbmmresults$atoms$p1[as.integer(substr(g, 3, 3))]- cdbmmresults$atoms$p_0[as.integer(substr(g, 1, 1))]) ```

Cite

bibtex @article{zorzetto2024confounder, title={Confounder-dependent Bayesian mixture model: Characterizing heterogeneity of causal effects in air pollution epidemiology}, author={Zorzetto, Dafne and Bargagli-Stoffi, Falco J and Canale, Antonio and Dominici, Francesca}, journal={Biometrics}, volume={80}, number={2}, year={2024}, publisher={Oxford University Press} }