Bayesian Network Modeling for Causal Inference: Cardiovascular Risk under Uncertainty
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Abstract
Causal inference under uncertainty remains difficult in applied health research because real-world systems contain interacting variables, incomplete information, and probabilistic pathways that cannot always be tested through direct experimentation. This study develops and empirically evaluates a Bayesian network framework for causal-informed inference using the Framingham cardiovascular-risk dataset. The dataset includes 4,240 participants, 16 variables, and a binary ten-year coronary heart disease (CHD) outcome, with 644 positive cases (15.19% of the sample). The proposed approach combines an expert-guided directed acyclic graph with data-estimated conditional probability tables to represent relationships among demographic, behavioral, metabolic, cardiovascular, and disease-outcome variables. We handled missing values using mode and median imputation, discretized continuous variables into clinically meaningful states, and performed posterior inference through evidence propagation. We evaluated the Bayesian network using a stratified 70/30 train-test split and probability-based measures. The model achieved an area under the receiver operating characteristic curve (ROC-AUC) of 0.674, a Brier score of 0.123, a log-loss of 0.404, and an accuracy of 0.846, indicating useful probabilistic discrimination and strong average calibration for a transparent graphical model. Evidence-scenario analysis showed that posterior CHD probability increased from 2.04% in a low-risk profile to 39.13% in an older hypertensive profile and 75.00% in a combined high-risk profile. Sensitivity analysis identified age, systolic blood pressure, diabetes, hypertension, and glucose status as the most influential sources of posterior risk change. The study contributes a reproducible Bayesian network workflow for uncertainty-aware causal reasoning and demonstrates how directed probabilistic graphs can improve explainability in cardiovascular decision support while avoiding unsupported causal certainty from observational data.
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1. Arora, P., Boyne, D., Slater, J. J., Gupta, A., Brenner, D. R., & Druzdzel, M. J. (2019). Bayesian networks for risk prediction using real-world data: A tool for precision medicine. Value in Health, 22(4), 439-445. DOI: https://doi.org/10.1016/j.jval.2019.01.006
2. Austin, P. C., & Steyerberg, E. W. (2019). The integrated calibration index for evaluating prediction models. Statistics in Medicine, 38(21), 4051-4065. DOI: https://doi.org/10.1002/sim.8281
3. Collins, G. S., Reitsma, J. B., Altman, D. G., & Moons, K. G. M. (2015). Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis: The TRIPOD statement. Annals of Internal Medicine, 162(1), 55-63. DOI: https://doi.org/10.7326/M14-0697
4. Fenton, N., & Neil, M. (2018). Risk assessment and decision analysis with Bayesian networks (2nd ed.). CRC Press. DOI: https://doi.org/10.1201/b21982
5. Gerds, T. A., & Kattan, M. W. (2021). Medical risk prediction models and statistical validation. Biometrical Journal, 63(7), 1-17. DOI: https://doi.org/10.1201/9781138384484-1
6. Glymour, C., Zhang, K., & Spirtes, P. (2019). Review of causal discovery methods based on graphical models. Frontiers in Genetics, 10, Article 524. DOI: https://doi.org/10.3389/fgene.2019.00524
7. Hauser, A., & Buhlmann, P. (2015). Jointly interventional and observational data: Estimation of interventional Markov equivalence classes of directed acyclic graphs. Journal of the Royal Statistical Society: Series B, 77(1), 291-318. DOI: https://doi.org/10.1111/rssb.12071
8. Heinze-Deml, C., Maathuis, M. H., & Meinshausen, N. (2018). Causal structure learning. Annual Review of Statistics and Its Application, 5, 371-391. DOI: https://doi.org/10.1146/annurev-statistics-031017-100630
9. Hernan, M. A., & Robins, J. M. (2020). Causal inference: What if. Chapman & Hall/CRC.
10. Hunte, J., Neil, M., & Fenton, N. (2022). A hybrid Bayesian network for medical device risk assessment and management. arXiv preprint arXiv:2209.03352.
11. Kuipers, J., Moffa, G., & Heckerman, D. (2014). Addendum on the scoring of Gaussian directed acyclic graphical models. The Annals of Statistics, 42(4), 1689-1691. DOI: https://doi.org/10.1214/14-AOS1217
12. Leckie, G., & Goldstein, H. (2019). The importance of uncertainty in modeling complex health data. Statistical Methods in Medical Research, 28(1), 1-14.
13. McLachlan, S., Dube, K., & Gallagher, T. (2020). Bayesian networks in healthcare: Distribution by clinical area and methodological properties. Health Informatics Journal, 26(1), 1-18.
14. Nagarajan, R., Scutari, M., & Lebre, S. (2013). Bayesian networks in R with applications in systems biology. Springer. DOI: https://doi.org/10.1007/978-1-4614-6446-4
15. Nandy, P., Maathuis, M. H., & Richardson, T. S. (2017). Estimating the effect of joint interventions from observational data in sparse high-dimensional settings. The Annals of Statistics, 45(2), 647-674. DOI: https://doi.org/10.1214/16-AOS1462
16. Ordovas, J. M., Rios Insua, D., Santos-Lozano, A., Lucia, A., Torres, A., Kosgodagan, A., & Camacho, J. M. (2021). A Bayesian network model for predicting cardiovascular risk. arXiv preprint arXiv:2112.13963.
17. Pearl, J., Glymour, M., & Jewell, N. P. (2016). Causal inference in statistics: A primer. Wiley.
18. Peters, J., Buhlmann, P., & Meinshausen, N. (2016). Causal inference by using invariant prediction: Identification and confidence intervals. Journal of the Royal Statistical Society: Series B, 78(5), 947-1012. DOI: https://doi.org/10.1111/rssb.12167
19. Peters, J., Janzing, D., & Scholkopf, B. (2017). Elements of causal inference: Foundations and learning algorithms. MIT Press.
20. Raskutti, G., & Uhler, C. (2018). Learning directed acyclic graph models based on sparsest permutations. Stat, 7(1), e183. DOI: https://doi.org/10.1002/sta4.183
21. Scutari, M., & Denis, J.-B. (2021). Bayesian networks: With examples in R (2nd ed.). CRC Press. DOI: https://doi.org/10.1201/9780429347436
22. Scutari, M., Vitolo, C., & Tucker, A. (2019). Learning Bayesian networks from big data with greedy search: Computational complexity and efficient implementation. Statistics and Computing, 29, 1095-1108. DOI: https://doi.org/10.1007/s11222-019-09857-1
23. Steyerberg, E. W., & Harrell, F. E. (2016). Prediction models need appropriate internal, internal-external, and external validation. Journal of Clinical Epidemiology, 69, 245-247. DOI: https://doi.org/10.1016/j.jclinepi.2015.04.005
24. Tennant, P. W. G., Murray, E. J., Arnold, K. F., Berrie, L., Fox, M. P., Gadd, S. C., Harrison, W. J., Keeble, C., Ranker, L. R., Textor, J., Tomova, G. D., Gilthorpe, M. S., & Ellison, G. T. H. (2021). Use of directed acyclic graphs in applied health research: Review and recommendations. International Journal of Epidemiology, 50(2), 620-632. DOI: https://doi.org/10.1093/ije/dyaa213
25. Textor, J., van der Zander, B., Gilthorpe, M. S., Liskiewicz, M., & Ellison, G. T. H. (2016). Robust causal inference using directed acyclic graphs: The R package dagitty. International Journal of Epidemiology, 45(6), 1887-1894. DOI: https://doi.org/10.1093/ije/dyw341
26. Tikka, S., & Karvanen, J. (2017). Identifying causal effects with the R package causaleffect. Journal of Statistical Software, 76(12), 1-30. DOI: https://doi.org/10.18637/jss.v076.i12
27. Van Calster, B., McLernon, D. J., van Smeden, M., Wynants, L., & Steyerberg, E. W. (2019). Calibration: The Achilles heel of predictive analytics. BMC Medicine, 17, Article 230. DOI: https://doi.org/10.1186/s12916-019-1466-7
28. Vowels, M. J., Camgoz, N. C., & Bowden, R. (2022). D’ya like DAGs? A survey on structure learning and causal discovery. ACM Computing Surveys, 55(4), 1-36. DOI: https://doi.org/10.1145/3527154
29. Wynants, L., Van Calster, B., Collins, G. S., Riley, R. D., Heinze, G., Schuit, E., Bonten, M. M. J., Damen, J. A. A., Debray, T. P. A., De Vos, M., Dhiman, P., Haller, M. C., Harhay, M. O., Henckaerts, L., Lohmann, A., Jenniskens, K., Kreuzberger, N., Luijken, K., Ma, J., ... Van Smeden, M. (2020). Prediction models for diagnosis and prognosis of COVID-19: Systematic review and critical appraisal. BMJ, 369, Article m1328. https://doi.org/10.1136/bmj.m1328 DOI: https://doi.org/10.1136/bmj.m1328
30. Zheng, X., Aragam, B., Ravikumar, P. K., & Xing, E. P. (2018). DAGs with no tears: Continuous optimization for structure learning. Conference proceedings, 9472-9483.