Sensitivity Analysis: Distributional Assumptions and Confounding Assumptions
- 28 June 2008
- journal article
- Published by Oxford University Press (OUP) in Biometrics
- Vol. 64 (2) , 645-649
Abstract
SummaryIn a presentation of various methods for assessing the sensitivity of regression results to unmeasured confounding,Lin, Psaty, and Kronmal(1998,Biometrics54, 948–963) use a conditional independence assumption to derive algebraic relationships between the true exposure effect and the apparent exposure effect in a reduced model that does not control for the unmeasured confounding variable. However,Hernán and Robins(1999,Biometrics55, 1316–1317) have noted that if the measured covariates and the unmeasured confounder both affect the exposure of interest then the principal conditional independence assumption that is used to derive these algebraic relationships cannot hold. One particular result of Lin et al. does not rely on the conditional independence assumption but only on assumptions concerning additivity. It can be shown that this assumption is satisfied for an entire family of distributions even if both the measured covariates and the unmeasured confounder affect the exposure of interest. These considerations clarify the appropriate contexts in which relevant sensitivity analysis techniques can be applied.Keywords
This publication has 12 references indexed in Scilit:
- The Sign of the Bias of Unmeasured ConfoundingBiometrics, 2008
- Bounding Causal Effects Under Uncontrolled Confounding Using CounterfactualsEpidemiology, 2005
- Sensitivity analyses for unmeasured confounding assuming a marginal structural model for repeated measuresStatistics in Medicine, 2004
- Sensitivity Analysis for Selection bias and unmeasured Confounding in missing Data and Causal inference models2000
- To the Editor of Biometrics:Biometrics, 1999
- Assessing the Sensitivity of Regression Results to Unmeasured Confounders in Observational Studies1998
- Bounds on Treatment Effects From Studies With Imperfect ComplianceJournal of the American Statistical Association, 1997
- Bounds on Treatment Effects from Studies with Imperfect ComplianceJournal of the American Statistical Association, 1997
- Inference for Non-random SamplesJournal of the Royal Statistical Society Series B: Statistical Methodology, 1997
- Causal diagrams for empirical researchBiometrika, 1995