An introduction to instrumental variables for epidemiologists

Int J Epidemiol. 2000 Aug;29(4):722-9. doi: 10.1093/ije/29.4.722.


Instrumental-variable (IV) methods were invented over 70 years ago, but remain uncommon in epidemiology. Over the past decade or so, non-parametric versions of IV methods have appeared that connect IV methods to causal and measurement-error models important in epidemiological applications. This paper provides an introduction to those developments, illustrated by an application of IV methods to non-parametric adjustment for non-compliance in randomized trials.

MeSH terms

  • Bias*
  • Child
  • Clinical Trials as Topic / statistics & numerical data
  • Confounding Factors, Epidemiologic*
  • Data Interpretation, Statistical
  • Effect Modifier, Epidemiologic*
  • Humans
  • Patient Compliance
  • Reproducibility of Results
  • Research Design / statistics & numerical data
  • Statistics as Topic / methods*
  • Vitamin A / therapeutic use


  • Vitamin A