Skip to main content

Effects of Adjusting for Instrumental Variables on Bias and Precision of Effect Estimates

    Basic Details

    The authors present results from two simulation studies to provide insight into the problem of conditioning on potential IVs in routine epidemiologic practice. The simulations explored the effects of conditioning on IVs, near IVs (predictors of exposure that are weakly associated with outcome), and confounders on the bias and variance of a binary exposure effect estimate.


    Jessica A. Myers PhD, ScD; Jeremy A. Rassen ScD; Joshua J. Gagne PharmD, MS; Krista F. Huybrechts PhD, MS; Sebastian Schneeweiss MD, ScD; Kenneth J. Rothman MPH, DrPH; Marshall M. Joffe MD, PhD, MPH; Robert J. Glynn PhD, ScD

    Corresponding Author

    J. A. Myers, Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, 1620 Tremont Street, Suite 3030, Boston, MA 02120, USA. Email: