title: Fitness-for-purpose of dietary survey duration: a case-study with the assessment of exposure to ochratoxin A.
abstract: The duration of food consumption survey may have a marked effect on estimates of usual nutrient intakes in individuals and groups. This arises from a high degree of within-person variability in food intakes, primarily on a day-to-day basis. Both the level of observation-populations versus individuals-and the desirable level of precision decide upon the 'fitness-for-purpose' of dietary survey duration. Though similar from a methodological standpoint, the question was rarely addressed in the case of non-nutrients. Our work aims at estimating the number of days of food records needed for the assessment of usual intakes of food chemicals as a function of research purpose. Focusing on the French population exposure to food mycotoxin ochratoxin A, we implement a range of well-established methods borrowed from the field of nutrient intakes assessment. Our results on OTA show that: (a) at the population level, as low as three days give satisfactory distributional estimates; yet, the implementation of variance reduction methods is of particular relevance when higher percentiles of exposure are at stake; (b) the estimation of individual usual intakes based on food records is behind practical possibilities, which calls for alternative options such as biomarkers of exposure.
authors.affiliation: INRA-Mét@risk, Méthodologie d'analyse du risque alimentaire, INA P-G, 16 rue Claude Bernard, 75231 Paris Cedex 5, France. Emilie.Counil@inapg.inra.f
authors.forename: E
authors.initials: E
authors.lastname: Counil
authors.forename: P
authors.initials: P
authors.lastname: Verger
authors.forename: J-L
authors.initials: JL
authors.lastname: Volatier
mesh_terms: D004034:Diet Surveys; D005247:Feeding Behavior; D005260:Female; D005506:Food Contamination; D005602:France; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009793:Ochratoxins / Q000032:analysis / Q000633:toxicity*; D013997:Time Factors
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A