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Evidence Synthesis & Systematic Review Program @ SJSU

This guide is intended to link SJSU faculty to the Evidence Synthesis & Systematic Review Program @ SJSU Library, as well as point them to resources that support systematic reviews and other forms of evidence synthesis.

Bias, Quality Assessment, and Conflicts of Interest in Included Studies

Systematic reviews strive to minimize bias in all aspects of its methodology. Cochrane defines bias as a "systematic error, or deviation from the truth, in results." Biases can skew the results of your study, such as by over- or under-estimating the effect of an intervention. Bias does not necessarily mean bad intentions on the part of the primary investigator; bias can be unavoidable due to constraints on how the study could be designed.

It is impossible for a systematic reviewer to know for sure whether bias has affected an included study. But you can assess a study's risk of bias. 

 
Guideline

MECIR C52 Assessing Risk of Bias (Mandatory) - "Assess the risk of bias for each study result contributing to an outcome in the ‘summary of findings’ table. For randomized trials, the RoB 2 tool should be used, involving judgements and support for those judgements across a series of domains of bias, as described in the Handbook." (Cochrane Handbook, MECIR Box 7.1.a Relevant expectations for conduct of intervention reviews

Quality and Bias Tools

Popular risk of bias tools include the following:

Find more risk of bias tools for specific study types, including observational and qualitative studies, at the following websites: