Instrumental variable (IV) methods have been proposed as a potential approach to the
common problem of uncontrolled confounding in comparative studies of medical …

Purpose Instrumental variable (IV) methods are used increasingly in pharmacoepidemiology
to address unmeasured confounding. In this tutorial, we review the steps used in IV analyses …

Instrumental variable analyses are increasingly used in epidemiologic studies. For
dichotomous exposures and outcomes, the typical 2-stage least squares approach produces …

The gold standard of study design for treatment evaluation is widely acknowledged to be the
randomized controlled trial (RCT). Trials allow for the estimation of causal effect by randomly …

Confounding by indication poses a significant threat to the validity of nonexperimental
studies assessing effectiveness and safety of medical interventions. While no different from …

Bias due to unobserved confounding can seldom be ruled out with certainty when estimating
the causal effect of a nonrandomized treatment. The instrumental variable (IV) design offers …

Observational studies of prescription medications and other medical interventions based on
administrative data are increasingly used to inform regulatory and clinical decision making …

© 2013 Lippincott Williams & Wilkins www. epidem. com| 371 via risk differences, odds
ratios, or partial r2 or F statistics like Davies et al5 did and several authors have …

Objectives: The goal of comparative effectiveness analysis is to examine the relationship
between two variables, treatment, or exposure and effectiveness or outcome. Unlike data …

OBJECTIVE: Instrumental variable (IV) analysis may offer a useful approach to the problem
of unmeasured confounding in prescription drug research if the IV is:(1) strongly and …