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Measurement error in dietary assessment: An investigation using covariance structure models. Part I
Author(s) -
Plummer Martyn,
Clayton David
Publication year - 1993
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.4780121004
Subject(s) - covariance , observational error , covariance matrix , statistics , repeated measures design , computer science , econometrics , errors in variables models , mathematics
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.