title: A statistical model for measurement error that incorporates variation over time in the target measure, with application to nutritional epidemiology.
abstract: Most statistical methods that adjust analyses for measurement error assume that the target exposure T is a fixed quantity for each individual. However, in many applications, the value of T for an individual varies with time. We develop a model that accounts for such variation, describing the model within the framework of a meta-analysis of validation studies of dietary self-report instruments, where the reference instruments are biomarkers. We demonstrate that in this application, the estimates of the attenuation factor and correlation with true intake, key parameters quantifying the accuracy of the self-report instrument, are sometimes substantially modified under the time-varying exposure model compared with estimates obtained under a traditional fixed-exposure model. We conclude that accounting for the time element in measurement error problems is potentially important.
authors.affiliation: Information Management Services, Inc., Rockville, MD, U.S.A.|Gertner Institute, Biostatistics Unit, Tel Hashomer, Israel.
authors.forename: Laurence S
authors.identifier: http://orcid.org/0000-0002-6767-7900
authors.initials: LS
authors.lastname: Freedman
authors.affiliation: National Cancer Institute, Division of Cancer Prevention, Bethesda, MD, U.S.A.
authors.forename: Douglas
authors.initials: D
authors.lastname: Midthune
authors.affiliation: National Cancer Institute, Division of Cancer Prevention, Bethesda, MD, U.S.A.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Dodd
authors.affiliation: Texas A&M University, Department of Statistics, College Station, TX, U.S.A.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Carroll
authors.affiliation: National Cancer Institute, Division of Cancer Prevention, Bethesda, MD, U.S.A.
authors.forename: Victor
authors.initials: V
authors.lastname: Kipnis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015982:Bias; D015415:Biomarkers; D015930:Diet Records; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015233:Models, Statistical; D057566:Self Report; D013997:Time Factors
chemical_list: D015415:Biomarkers
keywords: 24-hour recall; attenuation factor; calibration equations; food frequency questionnaire; recovery biomarker