How to assess for risk of bias


So, you’ve gathered your studies together and you’re ready to assess their risk of bias. What do you do next?

First, find a colleague.

Principle #1: Use the buddy system.
To make your decisions as consistent as possible, never conduct a risk of bias assessment alone. At least two people should assess each study.

The two assessors can either work independently or one person can double check the work of another person. If those people disagree, they discuss or consult a third person so that consensus is reached.

Second, establish clear criteria for assessing each study.

Principle #2: Use clear criteria for your assessment.

To guide your decision making, assess each study using a standardized approach. Be clear about the types of bias you’re looking for and what methods you’re using to find them. If you have no idea where to start, don’t worry. We’ll give you an example of how to do this later in the course.

Third, keep good notes.

Principle #3: Document your approach.

As we’ve mentioned earlier in this course, you’ll have to make a lot of judgement calls during your risk of bias assessment. Just be sure to keep track of your decisions so you can be transparent about the process.  

Let’s get started by describing the approach to risk of bias assessment.