
Confounder selection strategies targeting stable treatment effect estimators
- Author
- Wen Wei Loh (UGent) and Stijn Vansteelandt (UGent)
- Organization
- Abstract
- Inferring the causal effect of a treatment on an outcome in an observational study requires adjusting for observed baseline confounders to avoid bias. However, adjusting for all observed baseline covariates, when only a subset are confounders of the effect of interest, is known to yield potentially inefficient and unstable estimators of the treatment effect. Furthermore, it raises the risk of finite-sample bias and bias due to model misspecification. For these stated reasons, confounder (or covariate) selection is commonly used to determine a subset of the available covariates that is sufficient for confounding adjustment. In this article, we propose a confounder selection strategy that focuses on stable estimation of the treatment effect. In particular, when the propensity score (PS) model already includes covariates that are sufficient to adjust for confounding, then the addition of covariates that are associated with either treatment or outcome alone, but not both, should not systematically change the effect estimator. The proposal, therefore, entails first prioritizing covariates for inclusion in the PS model, then using a change-in-estimate approach to select the smallest adjustment set that yields a stable effect estimate. The ability of the proposal to correctly select confounders, and to ensure valid inference of the treatment effect following data-driven covariate selection, is assessed empirically and compared with existing methods using simulation studies. We demonstrate the procedure using three different publicly available datasets commonly used for causal inference.
- Keywords
- Statistics and Probability, Epidemiology, covariate selection, double selection, full matching, observational studies, randomization inference, VALID POST-SELECTION, VARIABLE SELECTION, PROPENSITY SCORE, CAUSAL, INFERENCE, UNCERTAINTY, DESIGN
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Citation
Please use this url to cite or link to this publication: http://hdl.handle.net/1854/LU-8688727
- MLA
- Loh, Wen Wei, and Stijn Vansteelandt. “Confounder Selection Strategies Targeting Stable Treatment Effect Estimators.” STATISTICS IN MEDICINE, vol. 40, no. 3, 2021, pp. 607–30, doi:10.1002/sim.8792.
- APA
- Loh, W. W., & Vansteelandt, S. (2021). Confounder selection strategies targeting stable treatment effect estimators. STATISTICS IN MEDICINE, 40(3), 607–630. https://doi.org/10.1002/sim.8792
- Chicago author-date
- Loh, Wen Wei, and Stijn Vansteelandt. 2021. “Confounder Selection Strategies Targeting Stable Treatment Effect Estimators.” STATISTICS IN MEDICINE 40 (3): 607–30. https://doi.org/10.1002/sim.8792.
- Chicago author-date (all authors)
- Loh, Wen Wei, and Stijn Vansteelandt. 2021. “Confounder Selection Strategies Targeting Stable Treatment Effect Estimators.” STATISTICS IN MEDICINE 40 (3): 607–630. doi:10.1002/sim.8792.
- Vancouver
- 1.Loh WW, Vansteelandt S. Confounder selection strategies targeting stable treatment effect estimators. STATISTICS IN MEDICINE. 2021;40(3):607–30.
- IEEE
- [1]W. W. Loh and S. Vansteelandt, “Confounder selection strategies targeting stable treatment effect estimators,” STATISTICS IN MEDICINE, vol. 40, no. 3, pp. 607–630, 2021.
@article{8688727, abstract = {{Inferring the causal effect of a treatment on an outcome in an observational study requires adjusting for observed baseline confounders to avoid bias. However, adjusting for all observed baseline covariates, when only a subset are confounders of the effect of interest, is known to yield potentially inefficient and unstable estimators of the treatment effect. Furthermore, it raises the risk of finite-sample bias and bias due to model misspecification. For these stated reasons, confounder (or covariate) selection is commonly used to determine a subset of the available covariates that is sufficient for confounding adjustment. In this article, we propose a confounder selection strategy that focuses on stable estimation of the treatment effect. In particular, when the propensity score (PS) model already includes covariates that are sufficient to adjust for confounding, then the addition of covariates that are associated with either treatment or outcome alone, but not both, should not systematically change the effect estimator. The proposal, therefore, entails first prioritizing covariates for inclusion in the PS model, then using a change-in-estimate approach to select the smallest adjustment set that yields a stable effect estimate. The ability of the proposal to correctly select confounders, and to ensure valid inference of the treatment effect following data-driven covariate selection, is assessed empirically and compared with existing methods using simulation studies. We demonstrate the procedure using three different publicly available datasets commonly used for causal inference.}}, author = {{Loh, Wen Wei and Vansteelandt, Stijn}}, issn = {{0277-6715}}, journal = {{STATISTICS IN MEDICINE}}, keywords = {{Statistics and Probability,Epidemiology,covariate selection,double selection,full matching,observational studies,randomization inference,VALID POST-SELECTION,VARIABLE SELECTION,PROPENSITY SCORE,CAUSAL,INFERENCE,UNCERTAINTY,DESIGN}}, language = {{eng}}, number = {{3}}, pages = {{607--630}}, title = {{Confounder selection strategies targeting stable treatment effect estimators}}, url = {{http://doi.org/10.1002/sim.8792}}, volume = {{40}}, year = {{2021}}, }
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