| Study | Reason for exclusion |
|---|---|
| Abad 2006 | Not a RCT |
| Al‐Saadi 2007 | Not a RCT |
| Arens 2005 | Not a RCT |
| Au 2009 | Not a RCT |
| Bianchi 2007 | Not a RCT |
| Chadha 2009 | Not a RCT |
| Chohan 2015 | Not a RCT |
| Ciprandi 2007 | No objective diagnosis of OSA |
| Cohen‐Gogo 2009 | Not a RCT |
| Criscuoli 2003 | No objective diagnosis of OSA |
| Demirhan 2010 | No objective diagnosis of OSA |
| Economu 2018 | Not a RCT |
| Erler 2004 | Not a RCT |
| Gelardi 2013 | No objective diagnosis of OSA |
| Goldbart 2008 | Not a RCT |
| Gudnadottir 2018 | No objective diagnosis of OSA |
| Hoban 2005 | Not a RCT |
| Hoban 2007 | Not a RCT |
| Hoban 2010 | Not a RCT |
| Kaditis 2006 | Not a RCT |
| Kheirandish‐Gozal 2013 | Not a RCT |
| Kotagal 2005 | Not a RCT |
| Kuhle 2009 | Not a RCT |
| Lam 2007 | Not a RCT |
| Lepcha 2002 | No objective diagnosis of OSA |
| Li 2004 | Not a RCT |
| Lipton 2003 | Not a RCT |
| Ng 2000 | Not a RCT |
| Nixon 2002 | Not a RCT |
| Nixon 2005 | Not a RCT |
| Praud 2008 | Not a RCT |
| Sakarya 2017 | Not a RCT |
| Shen 2014 | Not a RCT |
| Sterni 2003 | Not a RCT |
| Sujanska 2014 | Not a RCT |
| Tapia 2013 | Not a RCT |
| Traeger 2014 | Not a RCT |
| Varricchio 2009 | No objective diagnosis of OSA |
| Verse 2003 | Not a RCT |
| Wang 2017 | Comparison not against placebo |
| Wheeler 2002 | No objective diagnosis of OSA |
| Whitla 2016 | Not a RCT |
| Yang 2017 | Comparison not against placebo |
| Yu 2015 | Comparison not against placebo |
| Zhang 2008 | Not a RCT |
| Zhang 2017 | Not a RCT |
| Zhou 2002 | Not a RCT |
OSA: obstructive sleep apnoea; RCT: randomised controlled trial