TABLE 1.
Quality assessment (a summary of the risk of bias according to Cochrane criteria) of included studies investigating the effects of l-arginine supplementation on blood pressure in adults1
| Study (ref) | Random-sequence generation | Allocation concealment | Selective reporting | Other sources of bias | Blinding (participants and personnel) | Blinding (outcome assessment) | Incomplete outcome data | Random sequence generation | Quality |
|---|---|---|---|---|---|---|---|---|---|
| Chin-Dusting et al., 1996 (15) | U | U | L | U | L | U | L | U | Good |
| Clarkson et al., 1996 (41) | U | U | L | U | L | U | L | U | Good |
| Piatti et al., 2001 (42) | U | U | L | U | L | U | L | U | Good |
| Sydow et al., 2002 (43) | U | U | L | U | L | U | L | U | Good |
| Rytlewski et al., 2005 (12) | U | U | L | H | L | U | L | U | Good |
| West et al., 2005 (44) | U | U | L | U | L | U | L | U | Good |
| Hladunewich et al., 2006 (45) | L | L | L | U | L | U | L | L | Good |
| Lucotti et al., 2006 (47) | U | U | L | U | L | U | L | U | Good |
| Facchinetti et al., 2007 (48) | U | U | L | U | L | U | L | U | Good |
| Fontanive et al., 2009 (49) | U | U | L | U | L | U | H | U | Fair |
| Lucotti et al., 2009 (46) | U | U | L | U | L | U | L | U | Good |
| Ast et al. 2010 (11) | U | U | L | U | L | U | L | U | Good |
| Neri et al., 2010 (14) | U | U | L | U | L | U | L | U | Good |
| Battaglia et al., 2010 (50) | L | L | L | U | L | U | L | L | Good |
| Willoughby et al., 2011 (51) | U | L | H | L | L | U | L | U | Good |
| Ast et al., 2012(52) | U | U | L | U | L | U | L | U | Good |
| de Lima et al., 2012 (39) | U | U | L | U | U | U | L | U | Fair |
| Malfatti et al., 2014 (53) | U | U | H | U | U | U | H | U | Bad |
| Pahlavani et al., 2014 (54) | L | L | L | L | L | U | L | L | Good |
| Camarena Pulido et al., 2016 (55) | U | L | L | U | L | U | L | U | Good |
| McNeal et al., 2018 (56) | U | L | L | L | L | U | L | U | Good |
| Salmani et al., 2021 (40) | L | L | L | U | L | L | L | L | Good |
1
Bad, <2 low risk of bias; Good, >2 low risk of bias; Fair, = 2 low risk of bias. H, high risk of bias; L, low risk of bias; ref, reference; U, unclear risk of bias.