Importance: A systematic assessment of existing research should justify the conduct and inform the design of new clinical research but is often lacking. There is little research on the barriers to and factors facilitating systematic evidence assessments. Objective: To examine the practices and attitudes of Swiss stakeholders and international funders regarding conducting systematic evidence assessments in academic clinical trials. Design, Setting, and Participants: In this qualitative study, individual semistructured qualitative interviews were conducted between February and August 2020 with 48 Swiss stakeholder groups (27 primary investigators, 9 funders and sponsors, 6 clinical trial support organizations, and 6 ethics committee members) and between January and March 2021 with 9 international funders of clinical trials from North America and Europe with a reputation for requiring systematic evidence synthesis in applications for academic clinical trials. Main Outcomes and Measures: The main outcomes were practices and attitudes of Swiss stakeholders and international funders regarding conducting systematic evidence assessments in academic clinical trials. Interviews were analyzed using conventional content analysis. Results: Of the 57 participants, 40 (70.2%) were male. Participants universally acknowledged that a comprehensive understanding of the previous evidence is important but reported wide variation regarding how this should be achieved. Participants reported that the conduct of formal systematic reviews was currently not expected before most clinical trials, but most international funders reported expecting a systematic search for the existing evidence. Whereas time and resources were reported by all participants as barriers to conducting systematic reviews, the Swiss research ecosystem was reported not to be as supportive of a systematic approach compared with international settings. Conclusions and Relevance: In this qualitative study, Swiss stakeholders and international funders generally agreed that new clinical trials should be justified by a systematic evidence assessment but that barriers on individual, organizational, and political levels kept them from implementing it. More explicit requirements from funders appear to be needed to clarify the required level of comprehensiveness in summarizing existing evidence for different types of clinical trials.      «

Importance: A systematic assessment of existing research should justify the conduct and inform the design of new clinical research but is often lacking. There is little research on the barriers to and factors facilitating systematic evidence assessments. Objective: To examine the practices and attitudes of Swiss stakeholders and international funders regarding conducting systematic evidence assessments in academic clinical trials. Design, Setting, and Participants: In this qualitative study, ind...     »