Results
Between March 1st 2003 and December 1st 2023 189 studies started recruitment and were assessed for eligibility. Of these, 106 studies did not fulfil our inclusion criteria, such that in total 83 RCTs were included in the analyses (Figure 1). Characteristics of the included studies are summarized in Table 1. Fifteen RCTs did not have funding at all (18%). A more detailed list of all RCTs can be found as supplementary file Appendix 2(13-89).