Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/260

Title: Litter-based methods in developmental toxicity risk assessment
Authors: Declerck, Lieven
Molenberghs, Geert
Aerts, Marc
Ryan, Louise
Keywords: Clustered data
Categorical data
Issue Date: 2000
Publisher: KLUWER
Citation: Environmental and Ecological Statistics, 7(1). p. 57-76
Abstract: Developmental toxicity experiments are designed to assess potential adverse effects of drugs and other exposures on developing fetuses from pregnant dams. Extrapolation to humans is a very difficult problem. An important issue here is whether risk assessment should be based on the fetus or the litter level. In this paper, fetus and litter-based risks that properly account for cluster size are defined and compared for the beta-binomial model and a conditional model for clustered binary data. It is shown how the hierarchical structure of non-viable implants and viable but malformed offspring can be incorporated. Risks based on a joint model for death/resorption and malformation are contrasted with risks based on an adverse event defined as either death/resorption or malformation. The estimation of safe exposure levels for all risk types is discussed and it is shown how estimation of the cluster size distribution affects variance estimation. The methods are applied to data collected under the National Toxicology Program and in large sample simulations.
URI: http://hdl.handle.net/1942/260
DOI: 10.1023/A:1009658829383
ISI #: 000086412900005
ISSN: 1352-8505
Category: A1
Type: Journal Contribution
Validation: ecoom, 2001
Appears in Collections: Research publications

Files in This Item:

Description SizeFormat
Published version178.66 kBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.