A total of 240 articles (PubMed n = 129, Embase n = 111) were identified. Additionally, a manual search and cited reference search generated another 41 articles leading to a total of 281 articles, of which a title and abstract screening was executed by two authors independently. They identified those articles, which treated specific structural, procedural and evaluation issues of the CNBSS. One hundred and twenty-nine potentially relevant articles were saved for full text screening, while 53 articles were duplicates, 97 articles did not meet the inclusion criteria, and two articles were not available. These 129 articles were screened for the following topics: inclusion criteria, randomisation process, contamination of the control group, quality of mammograms, mammographic reading, and diagnostic chain. Forty-three articles were excluded, as they did not meet these inclusion criteria. Finally, 86 articles were selected for review (Fig. 1).
Fig. 1 Flow diagram of systematic literature search