From the Editors’ Desk: Bias in Systematic Reviews—Let the Reader Beware

Excerpt

Systematic reviews are relied upon by clinicians and policymakers as high-quality evidence for decision-making. In some hierarchies of evidence quality, systematic reviews are ranked at the top, higher than randomized controlled trials. A properly conducted systematic review that is based on high-quality articles provides very strong evidence; policymakers recognize this value and solicit many such reviews. Busy clinicians rely on well-executed systematic reviews to quickly synthesize the literature and guide them in managing patients. However, there are important inherent weaknesses that can limit the quality of systematic reviews and can lead to erroneous conclusions. Consumers of systematic reviews should approach them with a healthy sense of skepticism. Unfortunately, many of these weaknesses may not be obvious to the various stakeholders who routinely invest their trust in such reviews. …