title: Good practices for quantitative bias analysis.
abstract: Quantitative bias analysis serves several objectives in epidemiological research. First, it provides a quantitative estimate of the direction, magnitude and uncertainty arising from systematic errors. Second, the acts of identifying sources of systematic error, writing down models to quantify them, assigning values to the bias parameters and interpreting the results combat the human tendency towards overconfidence in research results, syntheses and critiques and the inferences that rest upon them. Finally, by suggesting aspects that dominate uncertainty in a particular research result or topic area, bias analysis can guide efficient allocation of sparse research resources. The fundamental methods of bias analyses have been known for decades, and there have been calls for more widespread use for nearly as long. There was a time when some believed that bias analyses were rarely undertaken because the methods were not widely known and because automated computing tools were not readily available to implement the methods. These shortcomings have been largely resolved. We must, therefore, contemplate other barriers to implementation. One possibility is that practitioners avoid the analyses because they lack confidence in the practice of bias analysis. The purpose of this paper is therefore to describe what we view as good practices for applying quantitative bias analysis to epidemiological data, directed towards those familiar with the methods. We focus on answering questions often posed to those of us who advocate incorporation of bias analysis methods into teaching and research. These include the following. When is bias analysis practical and productive? How does one select the biases that ought to be addressed? How does one select a method to model biases? How does one assign values to the parameters of a bias model? How does one present and interpret a bias analysis?. We hope that our guide to good practices for conducting and presenting bias analyses will encourage more widespread use of bias analysis to estimate the potential magnitude and direction of biases, as well as the uncertainty in estimates potentially influenced by the biases.
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA tlash@emory.edu.
authors: Timothy L
authors: TL
authors: Lash
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA.
authors: Matthew P
authors: MP
authors: Fox
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA.
authors: Richard F
authors: RF
authors: MacLehose
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA.
authors: George
authors: G
authors: Maldonado
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA.
authors: Lawrence C
authors: LC
authors: McCandless
authors: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Department of Epidemiology and Center for Global Health & Development, Boston University School of Public Health, Boston, MA, USA, Division of Epidemiology and Community Health and Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN, USA, Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada and Department of Epidemiology and Department of Statistics, University of California Los Angeles, Los Angeles, CA, USA.
authors: Sander
authors: S
authors: Greenland
mesh_terms: D015982:Bias; D004812:Epidemiologic Methods; D017408:Guidelines as Topic; D006801:Humans; D013223:Statistics as Topic
keywords: Epidemiological biases; analysis; best practice