title: Inference for case-control studies when exposure status is both informatively missing and misclassified.
abstract: In case-control studies, it is common for a categorical exposure variable to be misclassified. It is also common for exposure status to be informatively missing for some individuals, in that the probability of missingness may be related to exposure. Procedures for addressing the bias due to misclassification via validation data have been extensively studied, and related methods have been proposed for dealing with informative missingness based on supplemental sampling of some of those with missing data. In this paper, we introduce study designs and analytic procedures for dealing with both problems simultaneously in a 2x2 analysis. Results based on convergence in probability illustrate that the combined effects of missingness and misclassification, even when the latter is non-differential, can lead to naïve exposure odds ratio estimates that are inflated or on the wrong side of the null. The motivating example comes from a case-control study of the association between low birth weight and the diagnosis of breast cancer later in life, where self-reported birth weight for some women is supplemented by accurate information from birth certificates.
authors.affiliation: Department of Biostatistics, The Rollins School of Public Health of Emory University, Atlanta, GA 30322, USA. rlyles@sph.emory.edu
authors.forename: Robert H
authors.initials: RH
authors.lastname: Lyles
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Allen
authors.forename: W
authors.initials: W
authors.lastname: Dana Flanders
authors.forename: Lawrence L
authors.initials: LL
authors.lastname: Kupper
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Christensen
mesh_terms: D000328:Adult; D015982:Bias; D001943:Breast Neoplasms / Q000209:etiology; D016022:Case-Control Studies; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D016013:Likelihood Functions; D016017:Odds Ratio