Study	Reason for exclusion
Abe 1998	Non randomised, no surgical comparison arm
Al‐Adhami 2012	Retrospective study
Barakate 2002	Retrospective study
Boostrom 2007	Prospective study, non‐randomised
Campos 1994	Only one surgical arm
Candela 2006	Retrospective case series
De Bellis 2012	Non randomised, no surgical comparison arm
Fernandez‐Sanchez 1993	Only one surgical arm
Feroci 2014	Review
Guo 2013	Review
Hughes 2011	Total thyroidectomy both arms, non‐randomised
Hussain 2008	Non‐randomised, no surgical comparison arm
Jarhult 2012	Non randomised
Jukic 2010	Radio‐iodine versus surgery, no surgical comparison arm
Khandra 1992	Retrospective study
Ku 2005	Historical control group, non‐randomised
Kurihara 2002	Retrospective study
Leo 2012	No surgical comparison arm
Lepner 2008	Prospective study, non‐randomised
Ljunggren 1998	No surgical comparison arm
Lofthouse 2006	Review
Marcocci 1992	Retrospective study, no surgical comparison arm
Maschuw 2011	Protocol only, recruitment not complete due to lack of funding
Menconi 2007	Subtotal thyroidectomy in both arms, no comparison of alternative surgical technique
Miccoli 1996	Non‐randomised
Morosini 1988	Retrospective study
Robert 2001	Retrospective study
Rosato 2002	Retrospective study
Sanchez 1999	Retrospective study
Sugino 2008	Non‐randomised, no comparison of alternative surgical techniques
Tallstedt 1992	No alternative surgical technique comparison
Tallstedt 1997	Only one surgical arm
Tian 2012	No surgical comparison arm
Torring 1996	Only one surgical arm
Welch 2011	Consecutive, non‐randomised participants
Woods 2014	Meta‐analysis
Yalcin 2010	Retrospective study
Zaraca 2000	Retrospective study