Framework for Use of Screening Tools for Potentially Toxic Chemicals in Context-Based Decision-Making
Goal
The goal of the project is to develop a framework for evaluating the utility and application of screening tools for decision-making.
Project Rationale
Definitive information about the safety of an agent in a given human exposure scenario of interest is rarely available, so decisions are usually made on the basis of limited information. The extent of the information required depends on the context; in some situations, decisions may be made based on the results of short term assays while other decisions may be made on the basis of extensive information, including chronic bioassays. Screening tools are usually simple and rapid tests, studies or models that are designed to assist either in decision-making or in determining the need for additional testing. They are used in medicine for diagnostic purposes to detect disease and abnormal function and to guide and monitor therapy. In toxicology, screening methods are often designed and conducted for the purpose of identifying those agents that exhibit a set of attributes that either exclude them from further testing or cause them to undergo more rigorous evaluation. Screens are also used to conserve resources (animals, test agent, time), as range-finding tests or as surrogates for conventional toxicity studies and to provide supplemental information about specific adverse effects. The outputs from screening tests often identify a specific trait (or limited set of characteristics) that are associated with a known outcome in more in-depth testing.
Approach
ILSI RF/RSI initially established a steering committee to help frame the specific objectives and scope of the project, to identify the questions that should be answered by an Expert Panel and to provide input on the selection of the panel. The Expert Panel was convened in February 2003, and met four times to produce the report. A general framework for decision-making has been developed, which includes:
- Formulate and define the problem
- Identify tools to address specific questions
- Develop a plan on how to proceed
- List assumptions and caveats
- Assess degree of confidence in plan to address questions
- Make “Context-Based” decision
- Evaluate decision
Case studies have been developed to illustrate how the framework can be used effectively to address specific questions for cancer and non-cancer endpoints.
Current Status
The report has been submitted to Food and Chemical Toxicology.
This project was supported financially through a cooperative agreement with the US Environmental Protection Agency, Office of Pollution Prevention and Toxics.