Society for Risk Analysis
Dose Response Specialty Group
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Society for Risk Analysis |
DRSG Teleseminar: Wednesday, March 5, 2008 12:00 - 1:00 pm
Characterizing Dose-Response Model Uncertainty Using Model Averaging
Matthew Wheeler
Risk Evaluation Branch
National Institute for Occupational Safety and Health
Cincinnati, Ohio, USA
Abstract:
Given dose-response data and a suite of different models, each describing the data well (e.g., each model has adequate fit statistics given the data), researchers are frequently confronted with uncertainty in model selection. As selecting any single model disregards plausible information on the nature of the underlying dose-response curve, it is important that the nature of the model uncertainty be appropriately characterized in order to more fully inform risk management decisions. Model Averaging (MA) provides one such tool in characterizing model uncertainty, and has shown promise in effectively accounting for this uncertainty. A comprehensive simulation study of model averaging, in relation to dichotomous dose-response toxicity studies, is described (Wheeler and Bailer, Risk Analysis, 2007); along with software that implements this form of model averaging. Finally the use the MA dose-response curve, in calculating the benchmark dose and bench mark dose lower bound, is compared to using a linear extrapolation from the linearized multistage model at the approximate point of departure.
Slides:
Power-point: http://www.sra.org/drsg/docs/MWheeler_DRG_Talk.ppt
PDF: http://www.sra.org/drsg/docs/MWheeler_DRG_Talk_3-5-08.pdf
Contact Paul Feder for call-in number.
The Dose Response Specialty Group (DRSG), founded in 1994, is a subsection of the Society for Risk Analysis that focuses on the relationships between underlying causal mechanisms for toxic effects, population dose response relationships (including interindividual variability), and implications for regulatory choices. We are interested in probabilistic methods for projecting responses to assist in analyzing the benefits of measures that are expected to alter population exposures to chemical, physical, and microbial hazards. We are also interested in the integrated use of mechanistic, animal, and epidemiologic data to estimate risks at lower doses than can be directly assessed in animal toxicology or human studies. We provide fora for vigorous interdisciplinary exchange in our sponsored symposia and 3 teleseminars per year led by invited speakers. More information is provided in our DRSG poster (pdf files; may take a while to load).
DRSG-endorsed and other "interest" sessions scheduled for this year's SRA Annual Meeting, see:
DRSG 2007 Session Schedule.
Our teleseminars are held in March, June, and September in place of our regular monthly teleconferences from 12:00-1:00 PM (Eastern time) on the first Tuesday of the month. To join the electronic mail notification list on YahooGroups.com, go to http://groups.yahoo.com/group/DRSG/ and hit the "Join this Group!" button. All are welcome to participate in the teleseminars and our monthly discussions of annual meeting symposia, student awards, and other business.
You may also be interested in the report on "Adverse Effects" prepared by the Duke Center for Environmental Solutions.
