title: The withdrawal time estimation of veterinary drugs revisited.
abstract: The aim of this article is to review current issues concerning the statistical determination of a withdrawal time for a veterinary drug. Special attention has been paid to the Food and Drug Administration (FDA) approach which consists of using a regression method to estimate a 99th percentile of the population with a 95% confidence level. The different assumptions of the simple regression techniques are reviewed. It is shown, both on theoretical grounds and using Monte Carlo simulations, that the main assumptions for the correct use of linear regression do not hold when a tissue depletion curve is under investigation. Finally, it is suggested that methods other than the regression technique must be evaluated, especially a revised version of the so-called simpler approach, which consists of using a non-parametric strategy to estimate a withdrawal time.
authors.affiliation: Ecole Nationale Vétérinaire de Toulouse-INRA, Unité Associée INRA de Physiopathologie et Toxicologie Expérimentales, France.
authors.forename: D
authors.initials: D
authors.lastname: Concordet
authors.forename: P L
authors.initials: PL
authors.lastname: Toutain
mesh_terms: D000818:Animals; D004350:Drug Residues / Q000032:analysis*; D005602:France; D016014:Linear Models; D008460:Meat / Q000032:analysis*; D008954:Models, Biological; D009010:Monte Carlo Method; D016011:Normal Distribution; D013997:Time Factors; D014481:United States; D014486:United States Food and Drug Administration; D019155:Veterinary Drugs / Q000032:analysis* / Q000493:pharmacokinetics
chemical_list: D019155:Veterinary Drugs