Evidence reversal-when new evidence contradicts current claims: a systematic overview review of definitions and terms

To explore the terminology and definitions surrounding the phenomenon of evidence reversal (ER)-which occurs when an existing claim is tested and the original evidence is contradicted by new and stronger evidence.

For this systematic overview review, multiple medical and gray literature databases were systematically searched from inception to 2016 as well as hand searches of relevant journals, websites, blogs, article bibliographies, citing articles, and related articles. All reviews directly and indirectly defining ER were included and rated for quality using AMSTAR.

A total of 87 articles met the inclusion criteria. Fifty unique sets of terms related to ER were identified: nine described the phenomenon of reversal; 17 described the consequences of reversal; 20 described targets; four described potential predictors of reversal.

ER has only recently become a topic of formal exploration. There are many terms that relate to the concept of reversal, which fall into the categories of phenomenon, consequences, targets, and potential predictors of reversal. Consensus should be reached on which terms are most appropriate such that subject headings can be developed and cohesion can be brought to this emerging field of meta-research. (PROSPERO Registration number: CRD42014013768).