Study	Reason for exclusion
Abdullah 2001	Not a randomized controlled trial: reported on a case series of brain abscess (60 cases).
British Society 2000	Literature review on the antimicrobial treatment of brain abscess.
Gonzalez‐Garcia 1999	Not a randomized controlled trial: reported on a case series of brain abscess (100 cases).
Hirsch 1983	Not a randomized controlled trial: reported on a case series of brain abscess in children (34 cases).
Jansson 2004	Not a randomized controlled trial: reported on a case series of brain abscess (66 cases).
Lu 2002	Not a randomized controlled trial: reported on a case series of brain abscess (125 cases).
Mampalum 1988	Not a randomized controlled trial: reported on a case series of brain abscess (102 cases).
Seneviratne Rde 2003	Not a randomized controlled trial: reported on a case series of brain abscess (41 cases).
Yang 1981	Not a randomized controlled trial: reported on a case series of brain abscess (400 cases).