Rapid reviews have become a pragmatic alternative to traditional Systematic Reviews by streamlining methodological processes such as literature searches, aiming for faster provision of decision-relevant information to stakeholders within the healthcare sector and health decision making in general. The concordance of treatment effect estimates obtained from abbreviated (as conducted in rapid reviews with searches limited to major bibliographic databases, e.g. MEDLINE) and comprehensive literature searches (as performed in Cochrane systematic reviews and widely considered to be the benchmark) is unknown. Under the lead of Barbara Nußbaumer-Streit (co-director of Cochrane Austria), Thomas L Heise and Stefan K Lhachimi from the ebph-research group as well as other members of Cochrane Rapid Reviews and Cochrane Public Health Europe investigated this methodological research question by including 60 randomly selected Cochrane reviews and applying 14 different abbreviated search strategies (overall sample n = 840) to determine changes in conclusions of main results. To be more precise, the non-inferiority of abbreviated searches compared to original searches of Cochrane reviews was assessed. The main study findings got recently published in the Journal of Clinical Epidemiology. When falsely an opposite conclusion was of concern, combining one database with another (e.g. MEDLINE and CENTRAL) or with searches of reference lists was non-inferior to comprehensive searches as performed in the original Cochrane reviews. However, none of the abbreviated search approaches led to the overall quality of the original comprehensive search approaches, resulting in deviation of the main conclusions that were based on effect estimates of re-calculated meta-analyses. Decisions demanding high certainty should still require comprehensive searches. Nevertheless, some abbreviated searches represent viable options for rapid evidence synthesis.