Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13750-020-0187-x/MediaObjects/13750_2020_187_Fig1_HTML.png)
Flow diagram (N = number of articles, n = number of studies) adapted from ROSES [23]. The list of not retrieved full text and not eligible articles, with reasons for exclusion are detailed in Additional file 3. Notes: (1) Only the 10 first items could be saved; this technical problem was reported by contacting the site services but this had not resulted in a response or solution. (2) Priorization for these syntheses but no reason for non-inclusion of the other studies in further syntheses