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Abstract Instrumental variables is a popular method in epidemiology and related fields, to estimate causal effects in the presence of unmeasured confounding. Traditionally, instrumental variable analyses have been confined to linear models, in which the causal parameter of interest is typically...
Persistent link: https://www.econbiz.de/10014590645
We describe analytic approaches for study designs that, like large simple trials, can be better characterized as longitudinal studies with baseline randomization than as either a pure randomized experiment or a purely observational study. We (i) discuss the intention-to-treat effect as an effect...
Persistent link: https://www.econbiz.de/10005752622
This article describes the stgest command, which implements G-estimation (as proposed by Robins) to estimate the effect of a time-varying exposure on survival time, allowing for time-varying confounders. Copyright 2002 by Stata Corporation.
Persistent link: https://www.econbiz.de/10005583298
Abstract Unobserved confounding is a well-known threat to causal inference in non-experimental studies. The instrumental variable design can under certain conditions be used to recover an unbiased estimator of a treatment effect even if unobserved confounding cannot be ruled out with certainty....
Persistent link: https://www.econbiz.de/10014590602
Abstract The prognostic score, or disease risk score (DRS), is a summary score that is used to control for confounding in non-experimental studies. While the DRS has been shown to effectively control for measured confounders, unmeasured confounding continues to be a fundamental obstacle in...
Persistent link: https://www.econbiz.de/10014610811
Abstract Propensity score weighting is a tool for causal inference to adjust for measured confounders in observational studies. In practice, data often present complex structures, such as clustering, which make propensity score modeling and estimation challenging. In addition, for clustered...
Persistent link: https://www.econbiz.de/10014610867
Abstract The E-value is defined as the minimum strength of association on the risk ratio scale that an unmeasured confounder would have to have with both the exposure and the outcome, conditional on the measured covariates, to explain away the observed exposure-outcome association. We have...
Persistent link: https://www.econbiz.de/10014610871
In this paper, some new statistical methods are proposed, for making inferences about the parameter indexing a Cox proportional hazards marginal structural model for point exposure. Under the key assumption that unmeasured confounding is absent, we propose a new class of closed-form estimators...
Persistent link: https://www.econbiz.de/10011039989
Persistent link: https://www.econbiz.de/10014557447
In population based genetic association studies, confounding due to population stratification (PS) arises when differences in both allele and disease frequencies exist in a population of mixed racial/ethnic subpopulations. Propensity scores are often used to address confounding in observational...
Persistent link: https://www.econbiz.de/10009438626