title: Guidance for updating clinical practice guidelines: a systematic review of methodological handbooks.
abstract: BACKGROUND
  Updating clinical practice guidelines (CPGs) is a crucial process for maintaining the validity of recommendations. Methodological handbooks should provide guidance on both developing and updating CPGs. However, little is known about the updating guidance provided by these handbooks.
  
  
  METHODS
  We conducted a systematic review to identify and describe the updating guidance provided by CPG methodological handbooks and included handbooks that provide updating guidance for CPGs. We searched in the Guidelines International Network library, US National Guidelines Clearinghouse and MEDLINE (PubMed) from 1966 to September 2013. Two authors independently selected the handbooks and extracted the data. We used descriptive statistics to analyze the extracted data and conducted a narrative synthesis.
  
  
  RESULTS
  We included 35 handbooks. Most handbooks (97.1%) focus mainly on developing CPGs, including variable degrees of information about updating. Guidance on identifying new evidence and the methodology of assessing the need for an update is described in 11 (31.4%) and eight handbooks (22.8%), respectively. The period of time between two updates is described in 25 handbooks (71.4%), two to three years being the most frequent (40.0%). The majority of handbooks do not provide guidance for the literature search, evidence selection, assessment, synthesis, and external review of the updating process.
  
  
  CONCLUSIONS
  Guidance for updating CPGs is poorly described in methodological handbooks. This guidance should be more rigorous and explicit. This could lead to a more optimal updating process, and, ultimately to valid trustworthy guidelines.
authors.forename: Robin W M
authors.initials: RW
authors.lastname: Vernooij
authors.forename: Andrea Juliana
authors.initials: AJ
authors.lastname: Sanabria
authors.forename: Ivan
authors.initials: I
authors.lastname: Solà
authors.affiliation: Iberoamerican Cochrane Centre, Institute of Biomedical Research (IIB Sant Pau), C/ Sant Antoni Maria Claret 167, Barcelona 08025, Spain. palonso@santpau.cat.
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
authors.forename: Laura
authors.initials: L
authors.lastname: Martínez García
mesh_terms: D019317:Evidence-Based Medicine; D006801:Humans; D033181:Information Dissemination; D017410:Practice Guidelines as Topic