title: Systematic reviews of spinal manipulations for headaches: an attempt to clear up the confusion.
abstract: BACKGROUND
  Spinal manipulation (SM) is a therapy which is frequently used for headaches. During the last decade, several systematic reviews (SRs) of this topic have been published. Confusingly, their conclusions are far from uniform. The aim of this article is to identify the reasons for this confusion and to create more clarity about the therapeutic value of SM.
  
  
  METHODS
  SRs were identified through searches of Medline, Embase, Cochrane Library, Amed, Cinahl, and PsychInfo. They were considered if they were recent, systematic, and evaluated the effectiveness of SM for headache disorders.
  
  
  RESULTS
  Six SRs were included. Their methodological quality was assessed using the Oxman criteria for SRs. Five SRs were of high quality and one was associated with a high risk of bias. The findings of the SRs differed considerably. This variance seemed to be caused by several factors: differences in conditions included, treatments assessed, or primary studies analyzed.
  
  
  CONCLUSIONS
  We conclude that high-quality SRs with a clear focus are required before the value of SM for headaches can be defined.
authors: University of Exeter - Complementary Medicine, Exeter, Devon, UK.
authors: Paul
authors: P
authors: Posadzki
authors: Edzard
authors: E
authors: Ernst
mesh_terms: D000529:Complementary Therapies / Q000379:methods* / Q000592:standards / Q000639:trends*; D020773:Headache Disorders / Q000628:therapy*; D006801:Humans; D020393:Manipulation, Spinal / Q000379:methods* / Q000592:standards / Q000639:trends*; D015203:Reproducibility of Results