| Study | Reason for exclusion |
|---|---|
| Ali 2015 | Not an RCT |
| Altay 2015 | Not an RCT |
| Bakri 2002 | Duplicate study |
| Boboridis 2004 | Not an RCT |
| Camara 1999 | Not an RCT |
| Carifi 2014 | Not an RCT (letter to the editor) |
| ChiCTR‐INR‐16009702 | Not the intervention of interest |
| ChiCTR‐TRC‐09000721 | Not the intervention of interest |
| Costa 1992 | Duplicate study |
| CTRI/2014/09/004989 | Not an RCT |
| Deka 2006 | Not an RCT |
| Do 2016 | Not an RCT |
| Fan 2009 | Not an RCT |
| Farahani 2008 | Not the intervention of interest |
| IRCT201206216388N3 | Not the intervention of interest |
| IRCT201409166033N4 | Not the intervention of interest |
| Jawad 2015 | Not an RCT |
| Kim 2007 | Not an RCT |
| Leibovitch 2006 | Not an RCT |
| Li 2010 | Not the intervention of interest |
| Liao 2017 | Not the intervention of interest |
| Liu 2003 | Not the intervention of interest |
| Mudhol 2013a | Not the intervention of interest |
| NCT02636257 | Not the intervention of interest |
| NCT03780868 | Not the intervention of interest |
| Patel 2009 | Not an RCT |
| Piaton 2001 | Not an RCT |
| Qin 2010 | Not an RCT |
| Qiu 2016 | Not an RCT |
| Rathore 2009 | Not an RCT |
| Singh 2015 | Not an RCT |
| Tabatabaie 2007 | Not the intervention of interest |
| TCTR20161007003 | Not an RCT |
| Wang 2017 | Not the intervention of interest |
| Zeng 2008 | Not an RCT |
| Zhang 2006 | Not the population of interest |
| Zilelioglu 1998 | Not an RCT |
RCT: randomized controlled trial