title: A systematic literature review of complementary and alternative medicine prevalence in EU.
abstract: BACKGROUND
  Studies suggest that complementary and alternative medicine (CAM) is widely used in the European Union (EU). We systematically reviewed data, reporting research quality and the prevalence of CAM use by citizens in Europe; what it is used for, and why.
  
  
  METHODS
  We searched for general population surveys of CAM use by using Ovid MEDLINE (1948 to September 2010), Cochrane Library (1989 to September 2010), CINAHL (1989 to September 2010), EMBASE (1980 to September 2010), PsychINFO including PsychARTICLES (1989 to September 2010), Web of Science (1989 to September 2010), AMED (1985 to September 2010), and CISCOM (1989 to September 2010). Additional studies were identified through experts and grey literature. Cross-sectional, population-based or cohort studies reporting CAM use in any EU language were included. Data were extracted and reviewed by 2 authors using a pre-designed extraction protocol with quality assessment instrument.
  
  
  RESULTS
  87 studies were included. Inter-rater reliability was good (kappa = 0.8). Study methodology and quality of reporting were poor. The prevalence of CAM use varied widely within and across EU countries (0.3-86%). Prevalence data demonstrated substantial heterogeneity unrelated to report quality; therefore, we were unable to pool data for meta-analysis; our report is narrative and based on descriptive statistics. Herbal medicine was most commonly reported. CAM users were mainly women. The most common reason for use was dissatisfaction with conventional care; CAM was widely used for musculoskeletal problems.
  
  
  CONCLUSIONS
  CAM prevalence across the EU is problematic to estimate because studies are generally poor and heterogeneous. A consistent definition of CAM, a core set of CAMs with country-specific variations and a standardised reporting strategy to enhance the accuracy of data pooling would improve reporting quality.
authors.affiliation: Complementary and Integrated Medicine Research Unit, University of Southampton, UK.
authors.forename: Susan
authors.initials: S
authors.lastname: Eardley
authors.forename: Felicity L
authors.initials: FL
authors.lastname: Bishop
authors.forename: Philip
authors.initials: P
authors.lastname: Prescott
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardini
authors.forename: Benno
authors.initials: B
authors.lastname: Brinkhaus
authors.forename: Koldo
authors.initials: K
authors.lastname: Santos-Rey
authors.forename: Jorge
authors.initials: J
authors.lastname: Vas
authors.forename: Klaus
authors.initials: K
authors.lastname: von Ammon
authors.forename: Gabriella
authors.initials: G
authors.lastname: Hegyi
authors.forename: Simona
authors.initials: S
authors.lastname: Dragan
authors.forename: Bernard
authors.initials: B
authors.lastname: Uehleke
authors.forename: Vinjar
authors.initials: V
authors.lastname: Fønnebø
authors.forename: George
authors.initials: G
authors.lastname: Lewith
mesh_terms: D000529:Complementary Therapies / Q000706:statistics & numerical data*; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D005060:Europe; D005260:Female; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D029001:Herbal Medicine; D006705:Homeopathy; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D015203:Reproducibility of Results; D014600:Utilization Review / Q000706:statistics & numerical data