Table 2.

Validity of included studies

References	Randomization	Allocation concealment	Masking of participants	Masking of researches	Generation of random numbers reported	Reporting of withdraws	Jadad score
Basu 2011 [22]	Yes	Adequate	Yes	No	Yes	Yes	4
Bogdanski 2012 [23]	Yes	Adequate	Yes	Yes	No	Yes	4
Brown 2009 [24]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Brown 2011 [25]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Chan 2006 [26]	Yes	Unclear	Yes	Yes	Yes	Yes	4
Chen 2016	Yes	Adequate	Yes	Yes	Yes	Yes	5
Diepvens 2006 [28]	Yes	Unclear	Yes	Yes	No	No	2
Dostal 2016	Yes	Adequate	Yes	Yes	Yes	Yes	5
Frank 2009 [30]	Yes	Unclear	Yes	Yes	No	Yes	3
Fukino 2005 [31]	Yes	Unclear	No	No	No	Yes	2
Fukino 2008 [32]	Yes	Unclear	No	No	No	Yes	2
Hill 2007 [33]	Yes	Adequate	No	No	No	Yes	3
Hsu 2008 [34]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Hsu 2011 [35]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Kovacs 2004 [36]	Yes	Unclear	Yes	Yes	No	Yes	3
Liu 2014 [37]	Yes	Unclear	Yes	Yes	No	Yes	3
Lu 2016 [38]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Mielgo-Ayuso 2014 [39]	Yes	Adequate	Yes	Yes	Yes	Yes	5
Mirzaei 2009 [40]	Yes	Unclear	Yes	Yes	No	No	2
Miyazaki 2013 [41]	Yes	Unclear	Yes	Yes	No	Yes	3
Nagao 2007 [42]	Yes	Unclear	Yes	Yes	No	Yes	3
Nagao 2009 [43]	Yes	Unclear	Yes	Yes	No	Yes	3
Ryu 2006 [44]	Yes	Unclear	No	No	No	No	1
Sone 2011 [45]	Yes	Adequate	Yes	Yes	No	Yes	4
Suliburska 2012 [46]	Yes	Unclear	Yes	Yes	Yes	Yes	4
Tadayon 2018	Yes	Adequate	Yes	Yes	Yes	Yes	5
Wu 2012 [48]	Yes	Unclear	Yes	Yes	No	Yes	3