An Introduction to Instrumental Variables
نویسنده
چکیده
Instrumental variables (IVs) are used to control for confounding and measurement error in observational studies. They allow for the possibility of making causal inferences with observational data. Like propensity scores, IVs can adjust for both observed and unobserved confounding effects. Other methods of adjusting for confounding effects, which include stratification, matching and multiple regression methods, can only adjust for observed confounders. IVs have primarily been used in economics research, but have recently begun to appear in epidemiological studies.
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