Table 1.

Study characteristics.

Study	Year	Country	Randomization	Allocation	Dropouts n (%)
Fioravanti [46]	2015	Czech Republic, Italy, Spain	Not described	Unclear	3 (5.6)
Kim [47]	2014	Korea	Matched control design, not randomized	Unconcealed	3 (7.9)a
Logan [48]	2012	Canada	Block randomization using blocks of 4 and 6	Unclear	6 (5.5)
Takenga [49]	2014	Congo, Germany	Not described	Unclear	9 (22.5)
Waki [50]	2014	Japan	Not described	Unclear	5 (9.3)
Zhou [51]	2016	China	Random number table	Unclear	NAb

^aDropout only from the intervention group.

^bNA: not available.