| Study | Reason for exclusion |
|---|---|
| Afyounian 2017 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Alentorn 2014 | Concordance only data. |
| Aoki 2015a | 1p19q not assessed by ≥ 2 DNA techniques. |
| Aoki 2015b | 1p19q not assessed by ≥ 2 DNA techniques. |
| Assem 2009 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Assem 2012 | No results. |
| Bady 2013 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Ballester 2017 | Single case report. |
| Becker 2017 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Bienkowski 2018 | No results. |
| Boudreau 2004 | Not a primary study. |
| Brat 2015 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Buckley 2011 | Concordance only data. |
| Burgenske 2017 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Bystricka 2011 | Concordance only data. |
| Carrato 2006 | Concordance only data. |
| Carrato 2010 | Recruited based on 1p/19q status. |
| Carter 2016 | Concordance only data. |
| Castilla 2003 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Chernova 2003 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Cieply 2005 | Concordance only data. |
| Durand 2010 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Eckel‐Passow 2017 | Concordance only data. |
| Fontaine 2007 | Concordance only data. |
| Franco‐Hernandez 2009a | Concordance only data. |
| Franco‐Hernandez 2009b | 1p19q not assessed by ≥ 2 DNA techniques. |
| French 2005 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Garber 2016 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Hartmann 2005 | Not a primary study. |
| Hashimoto 2002 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Hench 2018 | Concordance only data. |
| Horbinski 2008 | Single case report. |
| Horbinski 2011 | Concordance only data. |
| Ida 2018 | Participants aged < 18 years. |
| Idbaih 2008 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Joo 2013 | Single case report. |
| Juratli 2012 | No results. |
| Kamoun 2015 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kashofer 2018 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kim 2016 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kitange 2004 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kitange 2005 | No results. |
| Klink 2010 | No results. |
| Klink 2011 | No results |
| Kouwenhoven 2009 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kuo 2009 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kuo 2013 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Kwon 2019 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Lautenschlaeger 2013 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Levine 2018 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Liu 2014 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Magnani 2003 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Martinez 2005 | Single case report. |
| Marucci 2012 | 1p19q not assessed by ≥ 2 DNA techniques. |
| McDonald 2005 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Mohapatra 2011 | No results. |
| Molinari 2010 | Concordance only data. |
| Mrachek 2018 | Recruited based on 1p/19q status. |
| Mur 2013 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Myung 2011 | Not a glioma. |
| Narasimhaiah 2010 | Concordance only data. |
| Neill 2015 | Single case report. |
| Nielsen 2007 | Not a primary study. |
| Parizi‐Robinson 2004 | Concordance only data. |
| Payne 2008 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Pekmezci 2016 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Pietsch 2015 | Participants aged < 18 years. |
| Pina‐Oviedo 2012 | Concordance only data. |
| Pinkham 2015 | Not a primary study. |
| Pinto 2008 | No results. |
| Ramkissoon 2015 | No results. |
| Rolston 2002 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Roy 2012 | Concordance only data. |
| Satomi 2018 | Concordance only data. |
| Satomi 2019 | Concordance only data. |
| Scheinin 2014 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Schiavo 2009 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Serrano 2015 | Concordance only data. |
| Tauziede‐Espariat 2018 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Walker 2000 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Woehrer 2015 | Not a primary study. |
| Xiu 2015 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Yokogami 2018 | Concordance only data. |
| Yoshimoto 2002 | 1p19q not assessed by ≥ 2 DNA techniques. |
| Zacher 2017 | Recruited based on 1p/19q status. |
| Zheng 2019 | Concordance only data. |
DNA: deoxyribonucleic acid.