Date	Event	Description
19 May 2017	New search has been performed	The previous version contained 48 trials (12 included, 32 excluded, three ongoing, one awaiting classification) (Guay 2015). We reran the search 19 May 2017. We found 15 new trials. We excluded seven of the new trials (Arora 2017; Cui 2015; Ding 2016; Ferrando 2015; Hosten 2017; Jain 2016; Liu 2016). Two of the new trials are ongoing (NCT01003730; NCT03157479). We included six new trials in the review (Kuzkov 2016; Park 2016a; Sato 2016; Shen 2015; Soh 2018; Xiong 2016). One trial that we classified as ongoing (NCT00747045) in the previous version of this review (Guay 2015), is now included (Bates 2015). We reran the search again 3 January 2018. Two additional trials published between May 2017 and January 2018 were also added to the list of studies awaiting classification for formal evaluation at the next update. However these two last trials do not mention any outcome of interest measured in their reports. This update contains 63 trials (19 included, 47 excluded, four awaiting classification, three ongoing)
19 May 2017	New citation required but conclusions have not changed	Conclusions unchanged by inclusion of seven additional trials (six new trials and publication of one of the ongoing trials of the previous version). Since the last publication, one author (SK) joined the review and no authors left the review. Methodology unchanged.