Measuring bias is tricky

When you’re evaluating a study for its risk of bias, what you’re really doing is asking yourself, “Can I trust the results from this study?”

But how do you measure trust? It’s not easy because what we are trying to measure is not quantifiable. We have to do a lot of thinking to decide whether we can trust the results of a study. And different systematic reviewers take different approaches, ranging from the simple to the complex.