All in the Family: systematic reviews, rapid reviews, scoping reviews, realist reviews, and more

Excerpt

Three years ago, we founded this journal focusing on publishing systematic reviews, systematic review protocols, and associated methodological development papers. Systematic reviews, which developed in the social sciences in the 1970s, began to gain rapid momentum during the 1990s in response to concerns by policymakers and clinicians about the scientific validity of the prevailing paradigm of traditional narrative reviews written by authoritative experts. What distinguished systematic reviews was the use of formal explicit methods, in other words pre-specification, of what exactly was the question to be answered, how evidence was searched for and assessed, and how it was synthesized in order to reach the conclusion. Importantly, these formal methods were described as part of the review itself in a Methods section. In turn, these methods themselves became the subject of hypothesis-testing studies, as investigators sought how best to search for evidence, assess studies for quality or risk of bias, determine under what conditions meta-analysis was justified, and how to best determine and characterize our confidence in the conclusions. The results of these hypothesis-testing studies led over time to improvements in the methods we use for systematic reviews. Thus, systematic reviews and this journal are part of an ever-evolving process whose foundations are rooted in the scientific method. …