title: Advances in meta-analysis: examples from internal medicine to neurology.
abstract: OBJECTIVE
  We review the state of the art in meta-analysis and data pooling following the evolution of the statistical models employed.
  
  
  METHODS
  Starting from a classic definition of meta-analysis of published data, a set of apparent antinomies which characterized the development of the meta-analytic tools are reconciled in dichotomies where the second term represents a possible generalization of the first one. Particular attention is given to the generalized linear mixed models as an overall framework for meta-analysis. Bayesian meta-analysis is discussed as a further possibility of generalization for sensitivity analysis and the use of priors as a data augmentation approach.
  
  
  RESULTS
  We provide relevant examples to underline how the need for adequate methods to solve practical issues in specific areas of research have guided the development of advanced methods in meta-analysis.
  
  
  CONCLUSIONS
  We show how all the advances in meta-analysis naturally merge into the unified framework of generalized linear mixed models and reconcile apparently conflicting approaches. All these complex models can be easily implemented with the standard commercial software available.
authors.affiliation: Unit of Biostatistics, Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Copetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Fontana
authors.forename: Giusi
authors.initials: G
authors.lastname: Graziano
authors.forename: Federica
authors.initials: F
authors.lastname: Veneziani
authors.forename: Federica
authors.initials: F
authors.lastname: Siena
authors.forename: Marco
authors.initials: M
authors.lastname: Scardapane
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lucisano
authors.forename: Fabio
authors.initials: F
authors.lastname: Pellegrini
mesh_terms: D006801:Humans; D007388:Internal Medicine / Q000379:methods / Q000592:standards*; D015201:Meta-Analysis as Topic; D009462:Neurology / Q000379:methods / Q000592:standards*