Table 2.

Newcastle-Ottawa Score for the included studies

Study	Selection				Comparability		Outcome			Total
Ekerstad 2011	1	1	1	1	1	0	1	0	1	7
Ekerstad 2014	1	1	1	1	1	0	1	1	1	8
Graham 2013	1	1	1	1	1	1	1	0	1	8
Sanchis 2014	1	1	1	1	1	1	1	1	0	8
Sanchis 2018	1	1	1	1	1	0	1	1	0	7
Kang 2015	1	1	1	1	1	0	1	0	1	7
Sujino 2015	0	1	1	1	1	0	1	0	0	5
White 2016	1	1	1	1	1	1	1	1	1	9
Alonso 2016 a	1	1	1	1	1	1	1	0	1	8
Alonso 2016 b	1	1	1	1	1	0	1	0	1	7
Alonso 2017	1	1	1	1	1	1	1	0	1	8
Alonso 2018	1	1	1	1	1	1	1	1	1	9
Kirill 2017	1	1	0	1	0	0	1	1	1	6
Blanco 2017	0	1	1	1	1	1	1	1	1	8
Alegre 2018	0	1	1	1	1	0	1	0	1	6