Study	Reason for exclusion
Arnold 1998	Review paper
Bartolini 2005	Reports data on chronic migraine only
Bavrasad 2010	Serious flaws including selective outcome reporting and concerns about data integrity
Blumenfeld 2008	Comparator is experimental
Cutrer 2001	Basic science paper
Erdemoglu 2000	No control group
Fragoso 2003	Letter to editor
Ghose 1998	No control group
Green 2005	Post hoc analysis of Klapper 1997 (included)
Keyvan 2009	Unknown number of participants were children. Lack of usable outcome data
Klapper 1994	No extractable data published
Krymchantowski 2011	No randomisation
Lenaerts 1996	No control group
Millan‐Guerrero 2007	Comparator is experimental
Rothrock 1994	No control group
Rothrock 1997	Review paper
Silberstein 1993	Conference abstract only
Sørensen 1988	No control group
Togha 2008	Comparator is experimental