CICI – An R package for causal inference with continuous (multiple time point) interventions.
This package facilitates the estimation of counterfactual outcomes for multiple values of continuous interventions at different time points and allows plotting of causal dose–response curves.
It provides implementations of both the (semi-)parametric g-formula and the sequential g-computation formula.
Positivity violations can be detected using diagnostics and addressed either through feasible intervention strategies or outcome weights.
Further details are provided in the manual and references below.
Author: Michael Schomaker
Contributors: Han Bao, Leo Fuhrhop, Katharina Ring
You can install the CICI package from CRAN:
install.packages("CICI")A comprehensive manual describing the functionality of the package is available here.
The R-code for the examples presented in the manual is here.
Additional examples are available on my homepage.
-
Schomaker, M., McIlleron, H., Denti, P., and Díaz, I. (2024).
Causal Inference for Continuous Multiple Time Point Interventions.
Statistics in Medicine, 43(28), 5380–5400. https://onlinelibrary.wiley.com/doi/full/10.1002/sim.10246 -
Bao, H. and Schomaker, M. (2026).
Feasible Dose-Response Curves for Continuous Treatments Under Positivity Violations.
ArXiv e-prints.
https://arxiv.org/abs/2502.14566 -
Ring, K. and Schomaker, M. (2026).
A Diagnostic to Find and Help Combat Stochastic Positivity Issues — with a Focus on Continuous Treatments.
Journal of Causal Inference, 14(1), 2026, pp. 20250007.
https://arxiv.org/abs/2502.11820 -
Holovchak, A., McIlleron, H., Denti, P., and Schomaker, M. (2025).
Recoverability of causal effects under presence of missing data: a longitudinal case study.
Biostatistics, 26(1), in press.
https://doi.org/10.1093/biostatistics/kxae044 -
Schomaker, M., Denti, P., Bienczak, A., Burger, D., Diaz, I., Gibb, D., Walker, S., and McIlleron, H. (2024).
Determining Targets for Antiretroviral Drug Concentrations: a Causal Framework Illustrated with Pediatric Efavirenz Data from the CHAPAS-3 Trial.
Pharmacoepidemiology and Drug Safety, 33, e70051. https://onlinelibrary.wiley.com/doi/full/10.1002/pds.70051