title: Measurement error in dietary assessment: an investigation using covariance structure models. Part I.
abstract: Repeated measures of diet are analysed in an attempt to discover the measurement error properties of various dietary assessment methods. It is customary in such studies to assume that one reference measurement is 'valid' (without error) but this assumption is not tenable. An alternative approach, widely used in social science, is to model the covariance matrix of the repeated measures. We apply this methodology to assessments of nitrogen intake, which is essentially equivalent to protein intake.
authors.affiliation: MRC Biostatistics Unit, Institute of Public Health, University Forvie Site, Cambridge, UK.
authors.forename: M
authors.initials: M
authors.lastname: Plummer
authors.forename: D
authors.initials: D
authors.lastname: Clayton
mesh_terms: D015982:Bias; D004044:Dietary Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D016014:Linear Models; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D009584:Nitrogen / Q000652:urine; D015596:Nutrition Assessment; D009749:Nutrition Surveys; D010865:Pilot Projects; D012016:Reference Values; D012107:Research Design
chemical_list: D004044:Dietary Proteins; D009584:Nitrogen