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https://ntp.niehs.nih.gov/go/riskbias

Risk of Bias Tool

The Risk of Bias Tool applies a parallel approach to the evaluation of study quality, or "risk of bias," for human and non-human animal studies, facilitating consideration of potential bias across evidence streams with common terminology and domains.

The Risk of Bias Tool evaluates the internal validity of a given study—that is, whether the study's design and conduct compromised the credibility of the link between exposure and outcome.

The risk of bias questions are followed by detailed criteria that define aspects of the study design, conduct, and reporting required to reach each risk-of-bias rating. This tool can be applied to many research questions, but in all cases should be tailored to the specifics of the systematic review.

We will refine and update the risk-of-bias tool as practices evolve and as empirical evidence is developed to support risk of bias elements.