Table 1.

Quality requirements of systematic searches derived from evidence synthesis guidelines

Source	Quality Requirements
Cochrane Handbook, 2011	“The key characteristics of a systematic review are: […] an explicit, reproducible methodology; a systematic search that attempts to identify all studies that would meet the eligibility criteria […].”14
Campbell Methods Guides, 2016	“Systematic reviews of interventions require a thorough, objective and reproducible search of a range of sources to identify as many relevant studies as possible (within resource limits).”15
CEE Guidelines and Standards for Environmental Evidence Synthesis, 2018	“To achieve a rigorous evidence synthesis searches should be transparent and reproducible and minimise biases. A key requirement of a review team engaged in evidence synthesis is to try to gather a maximum of the available relevant documented bibliographic evidence in articles and the studies reported therein.”16