Bias Detection Study Identifies Instruments for Evaluating Animal Studies

No good scientist wants to produce, or be accused of producing, a poorly conducted study. Even so, toxicologists conducting animal stud-ies are not widely expected to document the steps they take to ensure internal validity—that is, to prevent their results from being skewed due to a methodological issue (a concept known as risk of bias). This is likely to change soon, and a team of researchers at the University of California, San Francisco (UCSF) has taken a first step toward a solution by conducting a systematic literature review that identifies 30 instruments for evaluating risk of bias in animal research.1 “Risk of bias ” refers specifically to the introduction of systematic errors as a result of the way a study was conducted; it is unrelated to prejudice or manipulation of results to achieve a desired outcome. Other aspects of study quality include external validity (the extent to which results can be generalized) and reporting quality (descriptions of the exper-iment design, conduct, and analysis).2 Tools to assess these other aspect