Mendelian randomization in health research: Using appropriate genetic variants and avoiding biased estimates

Amy E Taylor, Neil M Davies, Jennifer J Ware, Tyler Vanderweele, George Davey Smith, Marcus R Munafò

Research output: Contribution to journalArticle (Academic Journal)

62 Citations (Scopus)

Abstract

Mendelian randomization methods, which use genetic variants as instrumental variables for exposures of interest to overcome problems of confounding and reverse causality, are becoming widespread for assessing causal relationships in epidemiological studies. The main purpose of this paper is to demonstrate how results can be biased if researchers select genetic variants on the basis of their association with the exposure in their own dataset, as often happens in candidate gene analyses. This can lead to estimates that indicate apparent "causal" relationships, despite there being no true effect of the exposure. In addition, we discuss the potential bias in estimates of magnitudes of effect from Mendelian randomization analyses when the measured exposure is a poor proxy for the true underlying exposure. We illustrate these points with specific reference to tobacco research.
Original languageEnglish
Pages (from-to)99-106
Number of pages8
JournalEconomics and Human Biology
Volume13
DOIs
Publication statusPublished - Mar 2014

Bibliographical note

Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Structured keywords

  • Brain and Behaviour
  • Tobacco and Alcohol

Keywords

  • Smoking
  • Tobacco
  • Mendelian randomization
  • Causal inference
  • Instrumental variable
  • DENSITY-LIPOPROTEIN CHOLESTEROL
  • INSTRUMENTAL VARIABLE ANALYSIS
  • CORONARY-HEART-DISEASE
  • C-REACTIVE PROTEIN
  • BODY-MASS INDEX
  • WEAK INSTRUMENTS
  • SMOKING QUANTITY
  • WEIGHT EVIDENCE
  • BIRTH-WEIGHT
  • LUNG-CANCER

Fingerprint Dive into the research topics of 'Mendelian randomization in health research: Using appropriate genetic variants and avoiding biased estimates'. Together they form a unique fingerprint.

  • Projects

    MRC UoB UNITE Unit - Programme 6

    Munafo, M. R. & Munafo, M. R.

    1/06/1331/03/18

    Project: Research

    IEU Theme 3

    Windmeijer, F., Tilling, K. M. & Tilling, K. M.

    1/06/1331/03/18

    Project: Research

    MRC UoB UNITE Unit - Programme 1

    Davey Smith, G.

    1/06/1331/03/18

    Project: Research

    Cite this